Fix the logic of setting read_amp_bytes_per_bit from OPTIONS file (#7680 )

Summary: Instead of using `EncodeFixed32` which always serialize a integer to little endian, we should use the local machine's endianness when populating a native data structure during options parsing. Without this fix, `read_amp_bytes_per_bit` may be populated incorrectly on big-endian machines. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7680 Test Plan: make check Reviewed By: pdillinger Differential Revision: D24999166 Pulled By: riversand963 fbshipit-source-id: dc603cff6e17f8fa32479ce6df93b93082e6b0c4
Bump version and update HISTORY
2026-07-07 22:55:23 +08:00 · 2020-11-17 10:18:19 -08:00 · 2020-11-15 15:04:28 -08:00 · 2020-11-15 14:52:54 -08:00 · 2020-11-11 12:21:58 -08:00 · 2020-10-12 13:15:15 -07:00
439 changed files with 27439 additions and 6560 deletions
@@ -6,12 +6,64 @@ orbs:
 executors:
  windows-2xlarge:
    machine:
-      image: 'windows-server-2019-vs2019:stable'
+      image: 'windows-server-2019-vs2019:201908-06'
      resource_class: windows.2xlarge
      shell: bash.exe

 jobs:
-  build:
+  build-linux:
+    machine:
+      image: ubuntu-1604:201903-01
+    resource_class: 2xlarge
+    steps:
+      - checkout # check out the code in the project directory
+      - run: pyenv global 3.5.2
+      - run: sudo apt-get update -y
+      - run: sudo apt-get install -y libgflags-dev
+      - run: SKIP_FORMAT_BUCK_CHECKS=1 PRINT_PARALLEL_OUTPUTS=1 make J=32 all check -j32
+
+  build-linux-release:
+    machine:
+      image: ubuntu-1604:201903-01
+    resource_class: 2xlarge
+    steps:
+      - checkout # check out the code in the project directory
+      - run: make release -j32
+
+  build-linux-lite:
+    machine:
+      image: ubuntu-1604:201903-01 
+    resource_class: 2xlarge
+    steps:
+      - checkout # check out the code in the project directory
+      - run: pyenv global 3.5.2
+      - run: SKIP_FORMAT_BUCK_CHECKS=1 PRINT_PARALLEL_OUTPUTS=1 LITE=1 make J=32 all check -j32
+
+  build-linux-lite-release:
+    machine:
+      image: ubuntu-1604:201903-01
+    resource_class: large
+    steps:
+      - checkout # check out the code in the project directory
+      - run: make release -j32
+
+  build-linux-clang-no-test:
+    machine:
+      image: ubuntu-1604:201903-01
+    resource_class: 2xlarge
+    steps:
+      - checkout # check out the code in the project directory
+      - run: USE_CLANG=1 make all -j32
+
+  build-linux-cmake:
+    machine:
+      image: ubuntu-1604:201903-01
+    resource_class: 2xlarge
+    steps:
+      - checkout # check out the code in the project directory
+      - run: mkdir build && cd build && cmake -DWITH_GFLAGS=0 .. && make -j32
+
+  build-windows:
    executor: windows-2xlarge
    
    environment:
@@ -54,3 +106,26 @@ jobs:
          shell: powershell.exe
          command: |
            build_tools\run_ci_db_test.ps1 -SuiteRun db_basic_test,db_test,db_test2,env_basic_test,env_test,db_merge_operand_test -Concurrency 16
+
+workflows:
+  build-linux:
+    jobs:
+      - build-linux
+  build-linux-lite:
+    jobs:
+      - build-linux-lite
+  build-linux-release:
+    jobs:
+      - build-linux-release
+  build-linux-lite-release:
+    jobs:
+      - build-linux-lite-release
+  build-linux-clang-no-test:
+    jobs:
+      - build-linux-clang-no-test
+  build-linux-cmake:
+    jobs:
+      - build-linux-cmake
+  build-windows:
+    jobs:
+      - build-windows
@@ -0,0 +1,41 @@
+name: Check buck targets and code format
+on: [push, pull_request]
+jobs:
+  check:
+    name: Check TARGETS file and code format
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout feature branch
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - name: Fetch from upstream
+      run: |
+        git remote add upstream https://github.com/facebook/rocksdb.git && git fetch upstream
+
+    - name: Where am I
+      run: |
+        echo git status && git status
+        echo "git remote -v" && git remote -v
+        echo git branch && git branch
+
+    - name: Setup Python
+      uses: actions/setup-python@v1
+
+    - name: Install Dependencies
+      run: python -m pip install --upgrade pip
+
+    - name: Install argparse
+      run: pip install argparse
+
+    - name: Download clang-format-diff.py
+      uses: wei/wget@v1
+      with:
+        args: https://raw.githubusercontent.com/llvm-mirror/clang/master/tools/clang-format/clang-format-diff.py
+
+    - name: Check format
+      run: VERBOSE_CHECK=1 make check-format
+
+    - name: Compare buckify output
+      run: make check-buck-targets
@@ -85,3 +85,5 @@ buckifier/*.pyc
 buckifier/__pycache__

 compile_commands.json
+clang-format-diff.py
+.py3/
@@ -50,14 +50,24 @@ env:
  - JOB_NAME=examples # 5-7 minutes
  - JOB_NAME=cmake # 3-5 minutes
  - JOB_NAME=cmake-gcc8 # 3-5 minutes
+  - JOB_NAME=cmake-gcc9 # 3-5 minutes
+  - JOB_NAME=cmake-gcc9-c++20 # 3-5 minutes
  - JOB_NAME=cmake-mingw # 3 minutes
+  - JOB_NAME=make-gcc4.8
+  - JOB_NAME=status_checked

 matrix:
  exclude:
  - os: osx
    env: JOB_NAME=cmake-gcc8
+  - os: osx
+    env: JOB_NAME=cmake-gcc9
+  - os: osx
+    env: JOB_NAME=cmake-gcc9-c++20
  - os: osx
    env: JOB_NAME=cmake-mingw
+  - os: osx
+    env: JOB_NAME=make-gcc4.8
  - os: osx
    arch: ppc64le
  - os: osx
@@ -65,88 +75,149 @@ matrix:
  - os : linux
    arch: arm64
    env: JOB_NAME=cmake-mingw
+  - os : linux
+    arch: arm64
+    env: JOB_NAME=make-gcc4.8
  - os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-mingw
+  - os: linux
+    arch: ppc64le
+    env: JOB_NAME=make-gcc4.8
  - os: linux
    compiler: clang
+  # Exclude all but most unique cmake variants for pull requests, but build all in branches
+  - if: type = pull_request
+    os : linux
+    arch: amd64
+    env: JOB_NAME=cmake
+  - if: type = pull_request
+    os : linux
+    arch: amd64
+    env: JOB_NAME=cmake-gcc8
+  - if: type = pull_request
+    os : linux
+    arch: amd64
+    env: JOB_NAME=cmake-gcc9
  # Exclude most osx, arm64 and ppc64le tests for pull requests, but build in branches
-  - if: type != pull_request
+  # Temporarily disable ppc64le unit tests in PRs until Travis gets its act together (#6653)
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: TEST_GROUP=platform_dependent
+  # NB: the cmake build is a partial java test
+  - if: type = pull_request
    os: osx
    env: TEST_GROUP=1
-  - if: type != pull_request
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: TEST_GROUP=1
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: TEST_GROUP=1
-  - if: type != pull_request
+  - if: type = pull_request
    os: osx
    env: TEST_GROUP=2
-  - if: type != pull_request
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: TEST_GROUP=2
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: TEST_GROUP=2
-  - if: type != pull_request
+  - if: type = pull_request
    os: osx
    env: TEST_GROUP=3
-  - if: type != pull_request
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: TEST_GROUP=3
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: TEST_GROUP=3
-  - if: type != pull_request
+  - if: type = pull_request
    os: osx
    env: TEST_GROUP=4
-  - if: type != pull_request
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: TEST_GROUP=4
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: TEST_GROUP=4
-  - if: type != pull_request
+  - if: type = pull_request AND commit_message !~ /java/
+    os : osx
+    env: JOB_NAME=java_test
+  - if: type = pull_request AND commit_message !~ /java/
    os : linux
    arch: arm64
-    env: JOB_NAME=java-test
-  - if: type != pull_request
+    env: JOB_NAME=java_test
+  - if: type = pull_request AND commit_message !~ /java/
    os: linux
    arch: ppc64le
-    env: JOB_NAME=java-test
-  - if: type != pull_request
+    env: JOB_NAME=java_test
+  - if: type = pull_request
+    os : osx
+    env: JOB_NAME=lite_build
+  - if: type = pull_request
    os : linux
    arch: arm64
-    env: JOB_NAME=lite-build
-  - if: type != pull_request
+    env: JOB_NAME=lite_build
+  - if: type = pull_request
    os: linux
    arch: ppc64le
-    env: JOB_NAME=lite-build
-  - if: type != pull_request
+    env: JOB_NAME=lite_build
+  - if: type = pull_request
+    os : osx
+    env: JOB_NAME=examples
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: JOB_NAME=examples
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: JOB_NAME=examples
-  - if: type != pull_request
+  - if: type = pull_request
    os : linux
    arch: arm64
    env: JOB_NAME=cmake-gcc8
-  - if: type != pull_request
+  - if: type = pull_request
    os: linux
    arch: ppc64le
    env: JOB_NAME=cmake-gcc8
+  - if: type = pull_request
+    os : linux
+    arch: arm64
+    env: JOB_NAME=cmake-gcc9
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: JOB_NAME=cmake-gcc9
+  - if: type = pull_request
+    os : linux
+    arch: arm64
+    env: JOB_NAME=cmake-gcc9-c++20
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: JOB_NAME=cmake-gcc9-c++20
+  - if: type = pull_request
+    os : osx
+    env: JOB_NAME=status_checked
+  - if: type = pull_request
+    os : linux
+    arch: arm64
+    env: JOB_NAME=status_checked
+  - if: type = pull_request
+    os: linux
+    arch: ppc64le
+    env: JOB_NAME=status_checked

 install:
  - if [ "${TRAVIS_OS_NAME}" == osx ]; then
@@ -156,9 +227,17 @@ install:
      sudo apt-get install -y g++-8;
      CC=gcc-8 && CXX=g++-8;
    fi
+  - if [ "${JOB_NAME}" == cmake-gcc9 ] || [ "${JOB_NAME}" == cmake-gcc9-c++20 ]; then
+      sudo apt-get install -y g++-9;
+      CC=gcc-9 && CXX=g++-9;
+    fi
  - if [ "${JOB_NAME}" == cmake-mingw ]; then
      sudo apt-get install -y mingw-w64 ;
    fi
+  - if [ "${JOB_NAME}" == make-gcc4.8 ]; then
+      sudo apt-get install -y g++-4.8 ;
+      CC=gcc-4.8 && CXX=g++-4.8;
+    fi
  - if [[ "${JOB_NAME}" == cmake* ]] && [ "${TRAVIS_OS_NAME}" == linux ]; then
      CMAKE_DIST_URL="https://rocksdb-deps.s3-us-west-2.amazonaws.com/cmake/cmake-3.14.5-Linux-$(uname -m).tar.bz2";
      TAR_OPT="--strip-components=1 -xj";
@@ -215,7 +294,7 @@ script:
      OPT=-DTRAVIS V=1 make rocksdbjava jtest
      ;;
    lite_build)
-      OPT='-DTRAVIS -DROCKSDB_LITE' V=1 make -j4 static_lib tools
+      OPT='-DTRAVIS -DROCKSDB_LITE' V=1 make -j4 all
      ;;
    examples)
      OPT=-DTRAVIS V=1 make -j4 static_lib && cd examples && make -j4
@@ -225,7 +304,19 @@ script:
      mkdir build && cd build && cmake -DJNI=1 -DWITH_GFLAGS=OFF .. -DCMAKE_C_COMPILER=x86_64-w64-mingw32-gcc -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++ -DCMAKE_SYSTEM_NAME=Windows && make -j4 rocksdb rocksdbjni
      ;;
    cmake*)
-      mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release && make -j4 rocksdb rocksdbjni
+      case $JOB_NAME in
+        *-c++20)
+          OPT=-DCMAKE_CXX_STANDARD=20
+          ;;
+      esac
+
+      mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j4 && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j4 rocksdb rocksdbjni
+      ;;
+    make-gcc4.8)
+      OPT=-DTRAVIS V=1 SKIP_LINK=1 make -j4 all && [ "Linking broken because libgflags compiled with newer ABI" ]
+      ;;
+    status_checked)
+      OPT=-DTRAVIS V=1 ASSERT_STATUS_CHECKED=1 make -j4 check_some
      ;;
    esac
 notifications:
@@ -83,6 +83,10 @@ else()
  option(WITH_FOLLY_DISTRIBUTED_MUTEX "build with folly::DistributedMutex" OFF)
 endif()

+if( NOT DEFINED CMAKE_CXX_STANDARD )
+  set(CMAKE_CXX_STANDARD 11)
+endif()
+
 include(CMakeDependentOption)
 CMAKE_DEPENDENT_OPTION(WITH_GFLAGS "build with GFlags" ON
  "NOT MSVC;NOT MINGW" OFF)
@@ -103,18 +107,32 @@ else()
    endif()
  endif()

-  # No config file for this
  if(WITH_GFLAGS)
-    find_package(gflags REQUIRED)
+    # Config with namespace available since gflags 2.2.2
+    option(GFLAGS_USE_TARGET_NAMESPACE "Use gflags import target with namespace." ON)
+    find_package(gflags CONFIG)
+    if(gflags_FOUND)
+      if(TARGET ${GFLAGS_TARGET})
+        # Config with GFLAGS_TARGET available since gflags 2.2.0
+        list(APPEND THIRDPARTY_LIBS ${GFLAGS_TARGET})
+      else()
+        # Config with GFLAGS_LIBRARIES available since gflags 2.1.0
+        list(APPEND THIRDPARTY_LIBS ${GFLAGS_LIBRARIES})
+      endif()
+    else()
+      find_package(gflags REQUIRED)
+      list(APPEND THIRDPARTY_LIBS gflags::gflags)
+    endif()
    add_definitions(-DGFLAGS=1)
-    include_directories(${gflags_INCLUDE_DIR})
-    list(APPEND THIRDPARTY_LIBS gflags::gflags)
  endif()

  if(WITH_SNAPPY)
-    find_package(snappy REQUIRED)
+    find_package(Snappy CONFIG)
+    if(NOT Snappy_FOUND)
+      find_package(Snappy REQUIRED)
+    endif()
    add_definitions(-DSNAPPY)
-    list(APPEND THIRDPARTY_LIBS snappy::snappy)
+    list(APPEND THIRDPARTY_LIBS Snappy::snappy)
  endif()

  if(WITH_ZLIB)
@@ -191,7 +209,6 @@ else()
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format -fno-asynchronous-unwind-tables")
    add_definitions(-D_POSIX_C_SOURCE=1)
  endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
  if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
    include(CheckCXXCompilerFlag)
@@ -254,6 +271,7 @@ include(CheckCXXSourceCompiles)
 if(NOT MSVC)
  set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()
+
 CHECK_CXX_SOURCE_COMPILES("
 #include <cstdint>
 #include <nmmintrin.h>
@@ -386,7 +404,15 @@ if(MSVC)
    message(STATUS "Debug optimization is enabled")
    set(CMAKE_CXX_FLAGS_DEBUG "/Oxt")
  else()
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1 /Gm")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Od /RTC1")
+
+    # Minimal Build is deprecated after MSVC 2015
+    if( MSVC_VERSION GREATER 1900 )
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm-")
+    else()
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /Gm")
+    endif()
+
  endif()
  if(WITH_RUNTIME_DEBUG)
    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /${RUNTIME_LIBRARY}d")
@@ -497,7 +523,6 @@ endif()

 include_directories(${PROJECT_SOURCE_DIR})
 include_directories(${PROJECT_SOURCE_DIR}/include)
-include_directories(SYSTEM ${PROJECT_SOURCE_DIR}/third-party/gtest-1.8.1/fused-src)
 if(WITH_FOLLY_DISTRIBUTED_MUTEX)
  include_directories(${PROJECT_SOURCE_DIR}/third-party/folly)
 endif()
@@ -506,12 +531,17 @@ find_package(Threads REQUIRED)
 # Main library source code

 set(SOURCES
+        cache/cache.cc
        cache/clock_cache.cc
        cache/lru_cache.cc
        cache/sharded_cache.cc
        db/arena_wrapped_db_iter.cc
        db/blob/blob_file_addition.cc
        db/blob/blob_file_garbage.cc
+        db/blob/blob_file_meta.cc
+        db/blob/blob_log_format.cc
+        db/blob/blob_log_reader.cc
+        db/blob/blob_log_writer.cc
        db/builder.cc
        db/c.cc
        db/column_family.cc
@@ -565,6 +595,7 @@ set(SOURCES
        db/trim_history_scheduler.cc
        db/version_builder.cc
        db/version_edit.cc
+        db/version_edit_handler.cc
        db/version_set.cc
        db/wal_manager.cc
        db/write_batch.cc
@@ -593,6 +624,7 @@ set(SOURCES
        memory/arena.cc
        memory/concurrent_arena.cc
        memory/jemalloc_nodump_allocator.cc
+        memory/memkind_kmem_allocator.cc
        memtable/alloc_tracker.cc
        memtable/hash_linklist_rep.cc
        memtable/hash_skiplist_rep.cc
@@ -617,7 +649,6 @@ set(SOURCES
        options/options.cc
        options/options_helper.cc
        options/options_parser.cc
-        options/options_sanity_check.cc
        port/stack_trace.cc
        table/adaptive/adaptive_table_factory.cc
        table/block_based/binary_search_index_reader.cc
@@ -702,9 +733,6 @@ set(SOURCES
        utilities/blob_db/blob_db_impl_filesnapshot.cc
        utilities/blob_db/blob_dump_tool.cc
        utilities/blob_db/blob_file.cc
-        utilities/blob_db/blob_log_reader.cc
-        utilities/blob_db/blob_log_writer.cc
-        utilities/blob_db/blob_log_format.cc
        utilities/cassandra/cassandra_compaction_filter.cc
        utilities/cassandra/format.cc
        utilities/cassandra/merge_operator.cc
@@ -775,9 +803,13 @@ if(WIN32)
    port/win/env_win.cc
    port/win/env_default.cc
    port/win/port_win.cc
-    port/win/win_logger.cc
-    port/win/win_thread.cc)
-
+    port/win/win_logger.cc)
+  if(NOT MINGW)
+    # Mingw only supports std::thread when using
+    # posix threads.
+    list(APPEND SOURCES
+      port/win/win_thread.cc)
+  endif()
 if(WITH_XPRESS)
  list(APPEND SOURCES
    port/win/xpress_win.cc)
@@ -824,12 +856,12 @@ else()
 endif()

 add_library(${ROCKSDB_STATIC_LIB} STATIC ${SOURCES})
-target_link_libraries(${ROCKSDB_STATIC_LIB}
+target_link_libraries(${ROCKSDB_STATIC_LIB} PRIVATE
  ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})

 if(ROCKSDB_BUILD_SHARED)
  add_library(${ROCKSDB_SHARED_LIB} SHARED ${SOURCES})
-  target_link_libraries(${ROCKSDB_SHARED_LIB}
+  target_link_libraries(${ROCKSDB_SHARED_LIB} PRIVATE
    ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})

  if(WIN32)
@@ -846,7 +878,6 @@ if(ROCKSDB_BUILD_SHARED)
                          LINKER_LANGUAGE CXX
                          VERSION ${rocksdb_VERSION}
                          SOVERSION ${rocksdb_VERSION_MAJOR}
-                          CXX_STANDARD 11
                          OUTPUT_NAME "rocksdb")
  endif()
 endif()
@@ -858,6 +889,16 @@ else()
 endif()

 option(WITH_JNI "build with JNI" OFF)
+# Tests are excluded from Release builds
+CMAKE_DEPENDENT_OPTION(WITH_TESTS "build with tests" ON
+  "CMAKE_BUILD_TYPE STREQUAL Debug" OFF)
+option(WITH_BENCHMARK_TOOLS "build with benchmarks" ON)
+option(WITH_CORE_TOOLS "build with ldb and sst_dump" ON)
+option(WITH_TOOLS "build with tools" ON)
+
+if(WITH_TESTS OR WITH_BENCHMARK_TOOLS OR WITH_TOOLS OR WITH_JNI OR JNI)
+  include_directories(SYSTEM ${PROJECT_SOURCE_DIR}/third-party/gtest-1.8.1/fused-src)
+endif()
 if(WITH_JNI OR JNI)
  message(STATUS "JNI library is enabled")
  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/java)
@@ -895,6 +936,8 @@ if(NOT WIN32 OR ROCKSDB_INSTALL_ON_WINDOWS)

  install(DIRECTORY include/rocksdb COMPONENT devel DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")

+  install(DIRECTORY "${PROJECT_SOURCE_DIR}/cmake/modules" COMPONENT devel DESTINATION ${package_config_destination})
+
  install(
    TARGETS ${ROCKSDB_STATIC_LIB}
    EXPORT RocksDBTargets
@@ -931,15 +974,11 @@ if(NOT WIN32 OR ROCKSDB_INSTALL_ON_WINDOWS)
  )
 endif()

-# Tests are excluded from Release builds
-CMAKE_DEPENDENT_OPTION(WITH_TESTS "build with tests" ON
-  "CMAKE_BUILD_TYPE STREQUAL Debug" OFF)
 if(WITH_TESTS)
  add_subdirectory(third-party/gtest-1.8.1/fused-src/gtest)
  add_library(testharness STATIC
  test_util/testharness.cc)
  target_link_libraries(testharness gtest)
-
  set(TESTS
        cache/cache_test.cc
        cache/lru_cache_test.cc
@@ -985,6 +1024,7 @@ if(WITH_TESTS)
        db/db_logical_block_size_cache_test.cc
        db/db_universal_compaction_test.cc
        db/db_wal_test.cc
+        db/db_with_timestamp_compaction_test.cc
        db/db_write_test.cc
        db/dbformat_test.cc
        db/deletefile_test.cc
@@ -1022,10 +1062,12 @@ if(WITH_TESTS)
        env/io_posix_test.cc
        env/mock_env_test.cc
        file/delete_scheduler_test.cc
+        file/random_access_file_reader_test.cc
        logging/auto_roll_logger_test.cc
        logging/env_logger_test.cc
        logging/event_logger_test.cc
        memory/arena_test.cc
+        memory/memkind_kmem_allocator_test.cc
        memtable/inlineskiplist_test.cc
        memtable/skiplist_test.cc
        memtable/write_buffer_manager_test.cc
@@ -1036,6 +1078,7 @@ if(WITH_TESTS)
        options/options_settable_test.cc
        options/options_test.cc
        table/block_based/block_based_filter_block_test.cc
+        table/block_based/block_based_table_reader_test.cc
        table/block_based/block_test.cc
        table/block_based/data_block_hash_index_test.cc
        table/block_based/full_filter_block_test.cc
@@ -1046,6 +1089,8 @@ if(WITH_TESTS)
        table/merger_test.cc
        table/sst_file_reader_test.cc
        table/table_test.cc
+        table/block_fetcher_test.cc
+        test_util/testutil_test.cc
        tools/block_cache_analyzer/block_cache_trace_analyzer_test.cc
        tools/ldb_cmd_test.cc
        tools/reduce_levels_test.cc
@@ -1067,8 +1112,10 @@ if(WITH_TESTS)
        util/slice_test.cc
        util/slice_transform_test.cc
        util/timer_queue_test.cc
+        util/timer_test.cc
        util/thread_list_test.cc
        util/thread_local_test.cc
+        util/work_queue_test.cc
        utilities/backupable/backupable_db_test.cc
        utilities/blob_db/blob_db_test.cc
        utilities/cassandra/cassandra_functional_test.cc
@@ -1088,6 +1135,7 @@ if(WITH_TESTS)
        utilities/table_properties_collectors/compact_on_deletion_collector_test.cc
        utilities/transactions/optimistic_transaction_test.cc
        utilities/transactions/transaction_test.cc
+        utilities/transactions/transaction_lock_mgr_test.cc
        utilities/transactions/write_prepared_transaction_test.cc
        utilities/transactions/write_unprepared_transaction_test.cc
        utilities/ttl/ttl_test.cc
@@ -1121,7 +1169,7 @@ if(WITH_TESTS)
        PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD_RELEASE 1
        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
-        )
+  )

  foreach(sourcefile ${TESTS})
      get_filename_component(exename ${sourcefile} NAME_WE)
@@ -1131,12 +1179,16 @@ if(WITH_TESTS)
        EXCLUDE_FROM_DEFAULT_BUILD_MINRELEASE 1
        EXCLUDE_FROM_DEFAULT_BUILD_RELWITHDEBINFO 1
        OUTPUT_NAME ${exename}${ARTIFACT_SUFFIX}
-        )
+      )
      target_link_libraries(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} testharness gtest ${ROCKSDB_LIB})
      if(NOT "${exename}" MATCHES "db_sanity_test")
        add_test(NAME ${exename} COMMAND ${exename}${ARTIFACT_SUFFIX})
        add_dependencies(check ${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX})
      endif()
+      if("${exename}" MATCHES "env_librados_test")
+        # env_librados_test.cc uses librados directly
+        target_link_libraries(${CMAKE_PROJECT_NAME}_${exename}${ARTIFACT_SUFFIX} rados)
+      endif()
  endforeach(sourcefile ${TESTS})

  if(WIN32)
@@ -1160,7 +1212,6 @@ if(WITH_TESTS)
  endif()
 endif()

-option(WITH_BENCHMARK_TOOLS "build with benchmarks" ON)
 if(WITH_BENCHMARK_TOOLS)
  add_executable(db_bench
    tools/db_bench.cc
@@ -1199,8 +1250,6 @@ if(WITH_BENCHMARK_TOOLS)
    ${ROCKSDB_LIB})
 endif()

-option(WITH_CORE_TOOLS "build with ldb and sst_dump" ON)
-option(WITH_TOOLS "build with tools" ON)
 if(WITH_CORE_TOOLS OR WITH_TOOLS)
  add_subdirectory(tools)
  add_custom_target(core_tools
@@ -1,18 +1,130 @@
 # Rocksdb Change Log
-## Unreleased
+## 6.11.7 (11/15/2020)
+### Bug Fixes
+* Fix a bug of encoding and parsing BlockBasedTableOptions::read_amp_bytes_per_bit as a 64-bit integer.
+* Fixed the logic of populating native data structure for `read_amp_bytes_per_bit` during OPTIONS file parsing on big-endian architecture. Without this fix, original code introduced in PR7659, when running on big-endian machine, can mistakenly store read_amp_bytes_per_bit (an uint32) in little endian format. Future access to `read_amp_bytes_per_bit` will give wrong values. Little endian architecture is not affected.
+
+## 6.11.6 (10/12/2020)
+### Bug Fixes
+* Fixed a bug in the following combination of features: indexes with user keys (`format_version >= 3`), indexes are partitioned (`index_type == kTwoLevelIndexSearch`), and some index partitions are pinned in memory (`BlockBasedTableOptions::pin_l0_filter_and_index_blocks_in_cache`). The bug could cause keys to be truncated when read from the index leading to wrong read results or other unexpected behavior.
+* Fixed a bug when indexes are partitioned (`index_type == kTwoLevelIndexSearch`), some index partitions are pinned in memory (`BlockBasedTableOptions::pin_l0_filter_and_index_blocks_in_cache`), and partitions reads could be mixed between block cache and directly from the file (e.g., with `enable_index_compression == 1` and `mmap_read == 1`, partitions that were stored uncompressed due to poor compression ratio would be read directly from the file via mmap, while partitions that were stored compressed would be read from block cache). The bug could cause index partitions to be mistakenly considered empty during reads leading to wrong read results.
+
+## 6.11.5 (7/23/2020)
+### Bug Fixes
+* Memtable lookup should report unrecognized value_type as corruption (#7121).
+
+## 6.11.4 (7/15/2020)
+### Bug Fixes
+* Make compaction report InternalKey corruption while iterating over the input.
+
+## 6.11.3 (7/9/2020)
+### Bug Fixes
+* Fix a bug when index_type == kTwoLevelIndexSearch in PartitionedIndexBuilder to update FlushPolicy to point to internal key partitioner when it changes from user-key mode to internal-key mode in index partition.
+* Disable file deletion after MANIFEST write/sync failure until db re-open or Resume() so that subsequent re-open will not see MANIFEST referencing deleted SSTs.
+
+## 6.11.1 (6/23/2020)
+### Bug Fixes
+* Best-efforts recovery ignores CURRENT file completely. If CURRENT file is missing during recovery, best-efforts recovery still proceeds with MANIFEST file(s).
+* In best-efforts recovery, an error that is not Corruption or IOError::kNotFound or IOError::kPathNotFound will be overwritten silently. Fix this by checking all non-ok cases and return early.
+* Compressed block cache was automatically disabled with read-only DBs by mistake. Now it is fixed: compressed block cache will be in effective with read-only DB too.
+* Fail recovery and report once hitting a physical log record checksum mismatch, while reading MANIFEST. RocksDB should not continue processing the MANIFEST any further.
+* Fix a bug of wrong iterator result if another thread finishes an update and a DB flush between two statement.
+
+### Public API Change
+* `DB::OpenForReadOnly()` now returns `Status::NotFound` when the specified DB directory does not exist. Previously the error returned depended on the underlying `Env`.
+
+## 6.11 (6/12/2020)
+### Bug Fixes
+* Fix consistency checking error swallowing in some cases when options.force_consistency_checks = true.
+* Fix possible false NotFound status from batched MultiGet using index type kHashSearch.
+* Fix corruption caused by enabling delete triggered compaction (NewCompactOnDeletionCollectorFactory) in universal compaction mode, along with parallel compactions. The bug can result in two parallel compactions picking the same input files, resulting in the DB resurrecting older and deleted versions of some keys.
+* Fix a use-after-free bug in best-efforts recovery. column_family_memtables_ needs to point to valid ColumnFamilySet.
+* Let best-efforts recovery ignore corrupted files during table loading.
+* Fix corrupt key read from ingested file when iterator direction switches from reverse to forward at a key that is a prefix of another key in the same file. It is only possible in files with a non-zero global seqno.
+* Fix abnormally large estimate from GetApproximateSizes when a range starts near the end of one SST file and near the beginning of another. Now GetApproximateSizes consistently and fairly includes the size of SST metadata in addition to data blocks, attributing metadata proportionally among the data blocks based on their size.
+* Fix potential file descriptor leakage in PosixEnv's IsDirectory() and NewRandomAccessFile().
+* Fix false negative from the VerifyChecksum() API when there is a checksum mismatch in an index partition block in a BlockBasedTable format table file (index_type is kTwoLevelIndexSearch).
+* Fix sst_dump to return non-zero exit code if the specified file is not a recognized SST file or fails requested checks.
+* Fix incorrect results from batched MultiGet for duplicate keys, when the duplicate key matches the largest key of an SST file and the value type for the key in the file is a merge value.
+
+### Public API Change
+* Flush(..., column_family) may return Status::ColumnFamilyDropped() instead of Status::InvalidArgument() if column_family is dropped while processing the flush request.
+* BlobDB now explicitly disallows using the default column family's storage directories as blob directory.
+* DeleteRange now returns `Status::InvalidArgument` if the range's end key comes before its start key according to the user comparator. Previously the behavior was undefined.
+* ldb now uses options.force_consistency_checks = true by default and "--disable_consistency_checks" is added to disable it.
+* DB::OpenForReadOnly no longer creates files or directories if the named DB does not exist, unless create_if_missing is set to true.
+* The consistency checks that validate LSM state changes (table file additions/deletions during flushes and compactions) are now stricter, more efficient, and no longer optional, i.e. they are performed even if `force_consistency_checks` is `false`.
+* Disable delete triggered compaction (NewCompactOnDeletionCollectorFactory) in universal compaction mode and num_levels = 1 in order to avoid a corruption bug.
+* `pin_l0_filter_and_index_blocks_in_cache` no longer applies to L0 files larger than `1.5 * write_buffer_size` to give more predictable memory usage. Such L0 files may exist due to intra-L0 compaction, external file ingestion, or user dynamically changing `write_buffer_size` (note, however, that files that are already pinned will continue being pinned, even after such a dynamic change).
+* In point-in-time wal recovery mode, fail database recovery in case of IOError while reading the WAL to avoid data loss.
+
+### New Features
+* sst_dump to add a new --readahead_size argument. Users can specify read size when scanning the data. Sst_dump also tries to prefetch tail part of the SST files so usually some number of I/Os are saved there too.
+* Generate file checksum in SstFileWriter if Options.file_checksum_gen_factory is set. The checksum and checksum function name are stored in ExternalSstFileInfo after the sst file write is finished.
+* Add a value_size_soft_limit in read options which limits the cumulative value size of keys read in batches in MultiGet. Once the cumulative value size of found keys exceeds read_options.value_size_soft_limit, all the remaining keys are returned with status Abort without further finding their values. By default the value_size_soft_limit is std::numeric_limits<uint64_t>::max().
+* Enable SST file ingestion with file checksum information when calling IngestExternalFiles(const std::vector<IngestExternalFileArg>& args). Added files_checksums and files_checksum_func_names to IngestExternalFileArg such that user can ingest the sst files with their file checksum information. Added verify_file_checksum to IngestExternalFileOptions (default is True). To be backward compatible, if DB does not enable file checksum or user does not provide checksum information (vectors of files_checksums and files_checksum_func_names are both empty), verification of file checksum is always sucessful. If DB enables file checksum, DB will always generate the checksum for each ingested SST file during Prepare stage of ingestion and store the checksum in Manifest, unless verify_file_checksum is False and checksum information is provided by the application. In this case, we only verify the checksum function name and directly store the ingested checksum in Manifest. If verify_file_checksum is set to True, DB will verify the ingested checksum and function name with the genrated ones. Any mismatch will fail the ingestion. Note that, if IngestExternalFileOptions::write_global_seqno is True, the seqno will be changed in the ingested file. Therefore, the checksum of the file will be changed. In this case, a new checksum will be generated after the seqno is updated and be stored in the Manifest.
+
+### Performance Improvements
+* Eliminate redundant key comparisons during random access in block-based tables.
+
+## 6.10 (5/2/2020)
+### Bug Fixes
+* Fix wrong result being read from ingested file. May happen when a key in the file happen to be prefix of another key also in the file. The issue can further cause more data corruption. The issue exists with rocksdb >= 5.0.0 since DB::IngestExternalFile() was introduced.
+* Finish implementation of BlockBasedTableOptions::IndexType::kBinarySearchWithFirstKey. It's now ready for use. Significantly reduces read amplification in some setups, especially for iterator seeks.
+* Fix a bug by updating CURRENT file so that it points to the correct MANIFEST file after best-efforts recovery.
+* Fixed a bug where ColumnFamilyHandle objects were not cleaned up in case an error happened during BlobDB's open after the base DB had been opened.
+* Fix a potential undefined behavior caused by trying to dereference nullable pointer (timestamp argument) in DB::MultiGet.
+* Fix a bug caused by not including user timestamp in MultiGet LookupKey construction. This can lead to wrong query result since the trailing bytes of a user key, if not shorter than timestamp, will be mistaken for user timestamp.
+* Fix a bug caused by using wrong compare function when sorting the input keys of MultiGet with timestamps.
+* Upgraded version of bzip library (1.0.6 -> 1.0.8) used with RocksJava to address potential vulnerabilities if an attacker can manipulate compressed data saved and loaded by RocksDB (not normal). See issue #6703.
+
+### Public API Change
+* Add a ConfigOptions argument to the APIs dealing with converting options to and from strings and files.  The ConfigOptions is meant to replace some of the options (such as input_strings_escaped and ignore_unknown_options) and allow for more parameters to be passed in the future without changing the function signature.
+* Add NewFileChecksumGenCrc32cFactory to the file checksum public API, such that the builtin Crc32c based file checksum generator factory can be used by applications.
+* Add IsDirectory to Env and FS to indicate if a path is a directory.
+
+### New Features
+* Added support for pipelined & parallel compression optimization for `BlockBasedTableBuilder`. This optimization makes block building, block compression and block appending a pipeline, and uses multiple threads to accelerate block compression. Users can set `CompressionOptions::parallel_threads` greater than 1 to enable compression parallelism. This feature is experimental for now.
+* Provide an allocator for memkind to be used with block cache. This is to work with memory technologies (Intel DCPMM is one such technology currently available) that require different libraries for allocation and management (such as PMDK and memkind). The high capacities available make it possible to provision large caches (up to several TBs in size) beyond what is achievable with DRAM.
+* Option `max_background_flushes` can be set dynamically using DB::SetDBOptions().
+* Added functionality in sst_dump tool to check the compressed file size for different compression levels and print the time spent on compressing files with each compression type. Added arguments `--compression_level_from` and `--compression_level_to` to report size of all compression levels and one compression_type must be specified with it so that it will report compressed sizes of one compression type with different levels.
+* Added statistics for redundant insertions into block cache: rocksdb.block.cache.*add.redundant. (There is currently no coordination to ensure that only one thread loads a table block when many threads are trying to access that same table block.)
+
+### Bug Fixes
+* Fix a bug when making options.bottommost_compression, options.compression_opts and options.bottommost_compression_opts dynamically changeable: the modified values are not written to option files or returned back to users when being queried.
+* Fix a bug where index key comparisons were unaccounted in `PerfContext::user_key_comparison_count` for lookups in files written with `format_version >= 3`.
+* Fix many bloom.filter statistics not being updated in batch MultiGet.
+
+### Performance Improvements
+* Improve performance of batch MultiGet with partitioned filters, by sharing block cache lookups to applicable filter blocks.
+* Reduced memory copies when fetching and uncompressing compressed blocks from sst files.
+
+## 6.9.0 (03/29/2020)
+### Behavior changes
+* Since RocksDB 6.8, ttl-based FIFO compaction can drop a file whose oldest key becomes older than options.ttl while others have not. This fix reverts this and makes ttl-based FIFO compaction use the file's flush time as the criterion. This fix also requires that max_open_files = -1 and compaction_options_fifo.allow_compaction = false to function properly.
+
 ### Public API Change
 * Fix spelling so that API now has correctly spelled transaction state name `COMMITTED`, while the old misspelled `COMMITED` is still available as an alias.
+* Updated default format_version in BlockBasedTableOptions from 2 to 4. SST files generated with the new default can be read by RocksDB versions 5.16 and newer, and use more efficient encoding of keys in index blocks.
+* A new parameter `CreateBackupOptions` is added to both `BackupEngine::CreateNewBackup` and `BackupEngine::CreateNewBackupWithMetadata`, you can decrease CPU priority of `BackupEngine`'s background threads by setting `decrease_background_thread_cpu_priority` and `background_thread_cpu_priority` in `CreateBackupOptions`.
+* Updated the public API of SST file checksum. Introduce the FileChecksumGenFactory to create the FileChecksumGenerator for each SST file, such that the FileChecksumGenerator is not shared and it can be more general for checksum implementations. Changed the FileChecksumGenerator interface from Value, Extend, and GetChecksum to Update, Finalize, and GetChecksum. Finalize should be only called once after all data is processed to generate the final checksum. Temproal data should be maintained by the FileChecksumGenerator object itself and finally it can return the checksum string.

 ### Bug Fixes
 * Fix a bug where range tombstone blocks in ingested files were cached incorrectly during ingestion. If range tombstones were read from those incorrectly cached blocks, the keys they covered would be exposed.
 * Fix a data race that might cause crash when calling DB::GetCreationTimeOfOldestFile() by a small chance. The bug was introduced in 6.6 Release.
+* Fix a bug where a boolean value optimize_filters_for_hits was for max threads when calling load table handles after a flush or compaction. The value is correct to 1. The bug should not cause user visible problems.
+* Fix a bug which might crash the service when write buffer manager fails to insert the dummy handle to the block cache.

 ### Performance Improvements
 * In CompactRange, for levels starting from 0, if the level does not have any file with any key falling in the specified range, the level is skipped. So instead of always compacting from level 0, the compaction starts from the first level with keys in the specified range until the last such level.
+* Reduced memory copy when reading sst footer and blobdb in direct IO mode.
+* When restarting a database with large numbers of sst files, large amount of CPU time is spent on getting logical block size of the sst files, which slows down the starting progress, this inefficiency is optimized away with an internal cache for the logical block sizes.

 ### New Features
 * Basic support for user timestamp in iterator. Seek/SeekToFirst/Next and lower/upper bounds are supported. Reverse iteration is not supported. Merge is not considered.
 * When file lock failure when the lock is held by the current process, return acquiring time and thread ID in the error message.
+* Added a new option, best_efforts_recovery (default: false), to allow database to open in a db dir with missing table files. During best efforts recovery, missing table files are ignored, and database recovers to the most recent state without missing table file. Cross-column-family consistency is not guaranteed even if WAL is enabled.
+* options.bottommost_compression, options.compression_opts and options.bottommost_compression_opts are now dynamically changeable.

 ## 6.8.0 (02/24/2020)
 ### Java API Changes
@@ -8,6 +8,11 @@

 BASH_EXISTS := $(shell which bash)
 SHELL := $(shell which bash)
+# Default to python3. Some distros like CentOS 8 do not have `python`.
+ifeq ($(origin PYTHON), undefined)
+	PYTHON := $(shell which python3 || which python || echo python3)
+endif
+export PYTHON

 CLEAN_FILES = # deliberately empty, so we can append below.
 CFLAGS += ${EXTRA_CFLAGS}
@@ -165,6 +170,12 @@ else
 	CXXFLAGS += -fno-rtti
 endif

+ifdef ASSERT_STATUS_CHECKED
+ifeq ($(filter -DROCKSDB_ASSERT_STATUS_CHECKED,$(OPT)),)
+	OPT += -DROCKSDB_ASSERT_STATUS_CHECKED
+endif
+endif
+
 $(warning Warning: Compiling in debug mode. Don't use the resulting binary in production)
 endif

@@ -186,12 +197,16 @@ AM_V_CC = $(am__v_CC_$(V))
 am__v_CC_ = $(am__v_CC_$(AM_DEFAULT_VERBOSITY))
 am__v_CC_0 = @echo "  CC      " $@;
 am__v_CC_1 =
-CCLD = $(CC)
-LINK = $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+
 AM_V_CCLD = $(am__v_CCLD_$(V))
 am__v_CCLD_ = $(am__v_CCLD_$(AM_DEFAULT_VERBOSITY))
+ifneq ($(SKIP_LINK), 1)
 am__v_CCLD_0 = @echo "  CCLD    " $@;
 am__v_CCLD_1 =
+else
+am__v_CCLD_0 = @echo "  !CCLD   " $@; true skip
+am__v_CCLD_1 = true skip
+endif
 AM_V_AR = $(am__v_AR_$(V))
 am__v_AR_ = $(am__v_AR_$(AM_DEFAULT_VERBOSITY))
 am__v_AR_0 = @echo "  AR      " $@;
@@ -203,8 +218,18 @@ LDFLAGS += -lrados
 endif

 AM_LINK = $(AM_V_CCLD)$(CXX) $^ $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
-# detect what platform we're building on
-dummy := $(shell (export ROCKSDB_ROOT="$(CURDIR)"; export PORTABLE="$(PORTABLE)"; "$(CURDIR)/build_tools/build_detect_platform" "$(CURDIR)/make_config.mk"))
+
+# Detect what platform we're building on.
+# Export some common variables that might have been passed as Make variables
+# instead of environment variables.
+dummy := $(shell (export ROCKSDB_ROOT="$(CURDIR)"; \
+                  export COMPILE_WITH_ASAN="$(COMPILE_WITH_ASAN)"; \
+                  export COMPILE_WITH_TSAN="$(COMPILE_WITH_TSAN)"; \
+                  export COMPILE_WITH_UBSAN="$(COMPILE_WITH_UBSAN)"; \
+                  export PORTABLE="$(PORTABLE)"; \
+                  export ROCKSDB_NO_FBCODE="$(ROCKSDB_NO_FBCODE)"; \
+                  export USE_CLANG="$(USE_CLANG)"; \
+                  "$(CURDIR)/build_tools/build_detect_platform" "$(CURDIR)/make_config.mk"))
 # this file is generated by the previous line to set build flags and sources
 include make_config.mk
 export JAVAC_ARGS
@@ -311,7 +336,7 @@ endif

 export GTEST_THROW_ON_FAILURE=1
 export GTEST_HAS_EXCEPTIONS=1
-GTEST_DIR = ./third-party/gtest-1.8.1/fused-src
+GTEST_DIR = third-party/gtest-1.8.1/fused-src
 # AIX: pre-defined system headers are surrounded by an extern "C" block
 ifeq ($(PLATFORM), OS_AIX)
 	PLATFORM_CCFLAGS += -I$(GTEST_DIR)
@@ -440,7 +465,12 @@ BENCHTOOLOBJECTS = $(BENCH_LIB_SOURCES:.cc=.o) $(LIBOBJECTS) $(TESTUTIL)

 ANALYZETOOLOBJECTS = $(ANALYZER_LIB_SOURCES:.cc=.o)

+ifeq ($(DEBUG_LEVEL),0)
 STRESSTOOLOBJECTS = $(STRESS_LIB_SOURCES:.cc=.o) $(LIBOBJECTS) $(TESTUTIL)
+else
+STRESSTOOLOBJECTS = $(STRESS_LIB_SOURCES:.cc=.o) $(LIBOBJECTS) $(TESTUTIL) \
+	$(TESTHARNESS)
+endif

 EXPOBJECTS = $(LIBOBJECTS) $(TESTUTIL)

@@ -465,6 +495,7 @@ TESTS = \
 	hash_test \
 	random_test \
 	thread_local_test \
+	work_queue_test \
 	rate_limiter_test \
 	perf_context_test \
 	iostats_context_test \
@@ -503,6 +534,7 @@ TESTS = \
 	column_family_test \
 	table_properties_collector_test \
 	arena_test \
+	memkind_kmem_allocator_test \
 	block_test \
 	data_block_hash_index_test \
 	cache_test \
@@ -513,8 +545,10 @@ TESTS = \
 	fault_injection_test \
 	filelock_test \
 	filename_test \
+	random_access_file_reader_test \
 	file_reader_writer_test \
 	block_based_filter_block_test \
+	block_based_table_reader_test \
 	full_filter_block_test \
 	partitioned_filter_block_test \
 	hash_table_test \
@@ -557,6 +591,7 @@ TESTS = \
 	deletefile_test \
 	obsolete_files_test \
 	table_test \
+	block_fetcher_test \
 	delete_scheduler_test \
 	options_test \
 	options_settable_test \
@@ -581,6 +616,7 @@ TESTS = \
 	compaction_job_stats_test \
 	option_change_migration_test \
 	transaction_test \
+	transaction_lock_mgr_test \
 	ldb_cmd_test \
 	persistent_cache_test \
 	statistics_test \
@@ -603,10 +639,9 @@ TESTS = \
 	defer_test \
 	blob_file_addition_test \
 	blob_file_garbage_test \
-
-ifeq ($(USE_FOLLY_DISTRIBUTED_MUTEX),1)
-	TESTS += folly_synchronization_distributed_mutex_test
-endif
+	timer_test \
+	db_with_timestamp_compaction_test \
+	testutil_test \

 PARALLEL_TEST = \
 	backupable_db_test \
@@ -627,13 +662,71 @@ PARALLEL_TEST = \
 	persistent_cache_test \
 	table_test \
 	transaction_test \
+	transaction_lock_mgr_test \
 	write_prepared_transaction_test \
 	write_unprepared_transaction_test \

+ifeq ($(USE_FOLLY_DISTRIBUTED_MUTEX),1)
+	TESTS += folly_synchronization_distributed_mutex_test
+	PARALLEL_TEST += folly_synchronization_distributed_mutex_test
+endif
+
 # options_settable_test doesn't pass with UBSAN as we use hack in the test
 ifdef COMPILE_WITH_UBSAN
        TESTS := $(shell echo $(TESTS) | sed 's/\boptions_settable_test\b//g')
 endif
+ifdef ASSERT_STATUS_CHECKED
+	# This is a new check for which we will add support incrementally. The
+	# whitelist can be removed once support is fully added.
+	TESTS_WHITELIST = \
+		arena_test \
+		autovector_test \
+		blob_file_addition_test \
+		blob_file_garbage_test \
+		bloom_test \
+		cassandra_format_test \
+		cassandra_row_merge_test \
+		cassandra_serialize_test \
+		cleanable_test \
+		coding_test \
+		crc32c_test \
+		dbformat_test \
+		defer_test \
+		dynamic_bloom_test \
+		event_logger_test \
+		file_indexer_test \
+		folly_synchronization_distributed_mutex_test \
+		hash_table_test \
+		hash_test \
+		heap_test \
+		histogram_test \
+		inlineskiplist_test \
+		io_posix_test \
+		iostats_context_test \
+		memkind_kmem_allocator_test \
+		merger_test \
+		mock_env_test \
+		object_registry_test \
+		options_settable_test \
+		options_test \
+		random_test \
+		range_del_aggregator_test \
+		range_tombstone_fragmenter_test \
+		repeatable_thread_test \
+		skiplist_test \
+		slice_test \
+		statistics_test \
+		thread_local_test \
+		timer_queue_test \
+		timer_test \
+		util_merge_operators_test \
+		version_edit_test \
+		work_queue_test \
+		write_controller_test \
+
+	TESTS := $(filter $(TESTS_WHITELIST),$(TESTS))
+	PARALLEL_TEST := $(filter $(TESTS_WHITELIST),$(PARALLEL_TEST))
+endif
 SUBSET := $(TESTS)
 ifdef ROCKSDBTESTS_START
        SUBSET := $(shell echo $(SUBSET) | sed 's/^.*$(ROCKSDBTESTS_START)/$(ROCKSDBTESTS_START)/')
@@ -885,6 +978,12 @@ J ?= 100%
 # Use this regexp to select the subset of tests whose names match.
 tests-regexp = .

+ifeq ($(PRINT_PARALLEL_OUTPUTS), 1)	
+	parallel_com = '{}'
+else
+	parallel_com = '{} >& t/log-{/}'
+endif
+
 .PHONY: check_0
 check_0:
 	$(AM_V_GEN)export TEST_TMPDIR=$(TMPD); \
@@ -898,7 +997,10 @@ check_0:
 	} \
 	  | $(prioritize_long_running_tests)				\
 	  | grep -E '$(tests-regexp)'					\
-	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu '{} >& t/log-{/}'
+	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu  $(parallel_com) ; \
+	parallel_retcode=$$? ; \
+	awk '{ if ($$7 != 0 || $$8 != 0) { if ($$7 == "Exitval") { h = $$0; } else { if (!f) print h; print; f = 1 } } } END { if(f) exit 1; }' < LOG ; \
+	if [ $$parallel_retcode -ne 0 ] ; then exit 1 ; fi

 valgrind-blacklist-regexp = InlineSkipTest.ConcurrentInsert|TransactionStressTest.DeadlockStress|DBCompactionTest.SuggestCompactRangeNoTwoLevel0Compactions|BackupableDBTest.RateLimiting|DBTest.CloseSpeedup|DBTest.ThreadStatusFlush|DBTest.RateLimitingTest|DBTest.EncodeDecompressedBlockSizeTest|FaultInjectionTest.UninstalledCompaction|HarnessTest.Randomized|ExternalSSTFileTest.CompactDuringAddFileRandom|ExternalSSTFileTest.IngestFileWithGlobalSeqnoRandomized|MySQLStyleTransactionTest.TransactionStressTest

@@ -932,6 +1034,9 @@ CLEAN_FILES += t LOG $(TMPD)
 watch-log:
 	$(WATCH) --interval=0 'sort -k7,7nr -k4,4gr LOG|$(quoted_perl_command)'

+dump-log:
+	bash -c '$(quoted_perl_command)' < LOG
+
 # If J != 1 and GNU parallel is installed, run the tests in parallel,
 # via the check_0 rule above.  Otherwise, run them sequentially.
 check: all
@@ -947,12 +1052,18 @@ check: all
 	fi
 	rm -rf $(TMPD)
 ifneq ($(PLATFORM), OS_AIX)
-	python tools/check_all_python.py
+	$(PYTHON) tools/check_all_python.py
 ifeq ($(filter -DROCKSDB_LITE,$(OPT)),)
-	python tools/ldb_test.py
+ifndef ASSERT_STATUS_CHECKED # not yet working with these tests
+	$(PYTHON) tools/ldb_test.py
 	sh tools/rocksdb_dump_test.sh
 endif
 endif
+endif	
+ifndef SKIP_FORMAT_BUCK_CHECKS
+	$(MAKE) check-format
+	$(MAKE) check-buck-targets
+endif

 # TODO add ldb_tests
 check_some: $(SUBSET)
@@ -960,7 +1071,7 @@ check_some: $(SUBSET)

 .PHONY: ldb_tests
 ldb_tests: ldb
-	python tools/ldb_test.py
+	$(PYTHON) tools/ldb_test.py

 crash_test: whitebox_crash_test blackbox_crash_test

@@ -969,31 +1080,31 @@ crash_test_with_atomic_flush: whitebox_crash_test_with_atomic_flush blackbox_cra
 crash_test_with_txn: whitebox_crash_test_with_txn blackbox_crash_test_with_txn

 blackbox_crash_test: db_stress
-	python -u tools/db_crashtest.py --simple blackbox $(CRASH_TEST_EXT_ARGS)
-	python -u tools/db_crashtest.py blackbox $(CRASH_TEST_EXT_ARGS)
+	$(PYTHON) -u tools/db_crashtest.py --simple blackbox $(CRASH_TEST_EXT_ARGS)
+	$(PYTHON) -u tools/db_crashtest.py blackbox $(CRASH_TEST_EXT_ARGS)

 blackbox_crash_test_with_atomic_flush: db_stress
-	python -u tools/db_crashtest.py --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)
+	$(PYTHON) -u tools/db_crashtest.py --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)

 blackbox_crash_test_with_txn: db_stress
-	python -u tools/db_crashtest.py --txn blackbox $(CRASH_TEST_EXT_ARGS)
+	$(PYTHON) -u tools/db_crashtest.py --txn blackbox $(CRASH_TEST_EXT_ARGS)

 ifeq ($(CRASH_TEST_KILL_ODD),)
  CRASH_TEST_KILL_ODD=888887
 endif

 whitebox_crash_test: db_stress
-	python -u tools/db_crashtest.py --simple whitebox --random_kill_odd \
+	$(PYTHON) -u tools/db_crashtest.py --simple whitebox --random_kill_odd \
      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
-	python -u tools/db_crashtest.py whitebox  --random_kill_odd \
+	$(PYTHON) -u tools/db_crashtest.py whitebox  --random_kill_odd \
      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)

 whitebox_crash_test_with_atomic_flush: db_stress
-	python -u tools/db_crashtest.py --cf_consistency whitebox  --random_kill_odd \
+	$(PYTHON) -u tools/db_crashtest.py --cf_consistency whitebox  --random_kill_odd \
      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)

 whitebox_crash_test_with_txn: db_stress
-	python -u tools/db_crashtest.py --txn whitebox --random_kill_odd \
+	$(PYTHON) -u tools/db_crashtest.py --txn whitebox --random_kill_odd \
      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)

 asan_check:
@@ -1173,6 +1284,12 @@ tags0:
 format:
 	build_tools/format-diff.sh

+check-format:
+	build_tools/format-diff.sh -c
+
+check-buck-targets:
+	buckifier/check_buck_targets.sh
+
 package:
 	bash build_tools/make_package.sh $(SHARED_MAJOR).$(SHARED_MINOR)

@@ -1236,6 +1353,9 @@ db_repl_stress: tools/db_repl_stress.o $(LIBOBJECTS) $(TESTUTIL)
 arena_test: memory/arena_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+memkind_kmem_allocator_test: memory/memkind_kmem_allocator_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 autovector_test: util/autovector_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1293,6 +1413,9 @@ histogram_test: monitoring/histogram_test.o $(LIBOBJECTS) $(TESTHARNESS)
 thread_local_test: util/thread_local_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+work_queue_test: util/work_queue_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 corruption_test: db/corruption_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1311,6 +1434,9 @@ db_basic_test: db/db_basic_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
 db_with_timestamp_basic_test: db/db_with_timestamp_basic_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+db_with_timestamp_compaction_test: db/db_with_timestamp_compaction_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 db_encryption_test: db/db_encryption_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1505,12 +1631,18 @@ delete_scheduler_test: file/delete_scheduler_test.o $(LIBOBJECTS) $(TESTHARNESS)
 filename_test: db/filename_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+random_access_file_reader_test: file/random_access_file_reader_test.o $(LIBOBJECTS) $(TESTHARNESS) $(TESTUTIL)
+	$(AM_LINK)
+
 file_reader_writer_test: util/file_reader_writer_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

 block_based_filter_block_test: table/block_based/block_based_filter_block_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+block_based_table_reader_test: table/block_based/block_based_table_reader_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 full_filter_block_test: table/block_based/full_filter_block_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1526,6 +1658,9 @@ cleanable_test: table/cleanable_test.o $(LIBOBJECTS) $(TESTHARNESS)
 table_test: table/table_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+block_fetcher_test: table/block_fetcher_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 block_test: table/block_based/block_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1664,6 +1799,9 @@ write_callback_test: db/write_callback_test.o $(LIBOBJECTS) $(TESTHARNESS)
 heap_test: util/heap_test.o $(GTEST)
 	$(AM_LINK)

+transaction_lock_mgr_test: utilities/transactions/transaction_lock_mgr_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 transaction_test: utilities/transactions/transaction_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1739,6 +1877,12 @@ blob_file_addition_test: db/blob/blob_file_addition_test.o $(LIBOBJECTS) $(TESTH
 blob_file_garbage_test: db/blob/blob_file_garbage_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+timer_test: util/timer_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
+testutil_test: test_util/testutil_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 #-------------------------------------------------
 # make install related stuff
 INSTALL_PATH ?= /usr/local
@@ -1818,9 +1962,9 @@ SHA256_CMD = sha256sum
 ZLIB_VER ?= 1.2.11
 ZLIB_SHA256 ?= c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1
 ZLIB_DOWNLOAD_BASE ?= http://zlib.net
-BZIP2_VER ?= 1.0.6
-BZIP2_SHA256 ?= a2848f34fcd5d6cf47def00461fcb528a0484d8edef8208d6d2e2909dc61d9cd
-BZIP2_DOWNLOAD_BASE ?= https://downloads.sourceforge.net/project/bzip2
+BZIP2_VER ?= 1.0.8
+BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269
+BZIP2_DOWNLOAD_BASE ?= https://sourceware.org/pub/bzip2
 SNAPPY_VER ?= 1.1.8
 SNAPPY_SHA256 ?= 16b677f07832a612b0836178db7f374e414f94657c138e6993cbfc5dcc58651f
 SNAPPY_DOWNLOAD_BASE ?= https://github.com/google/snappy/archive
@@ -2089,7 +2233,7 @@ jtest_run:

 jtest: rocksdbjava
 	cd java;$(MAKE) sample;$(MAKE) test;
-	python tools/check_all_python.py # TODO peterd: find a better place for this check in CI targets
+	$(PYTHON) tools/check_all_python.py # TODO peterd: find a better place for this check in CI targets

 jdb_bench:
 	cd java;$(MAKE) db_bench;
@@ -2147,6 +2291,7 @@ endif
 #  	Source files dependencies detection
 # ---------------------------------------------------------------------------

+# FIXME: nothing checks that entries in MAIN_SOURCES actually exist
 all_sources = $(LIB_SOURCES) $(MAIN_SOURCES) $(MOCK_LIB_SOURCES) $(TOOL_LIB_SOURCES) $(BENCH_LIB_SOURCES) $(TEST_LIB_SOURCES) $(ANALYZER_LIB_SOURCES) $(STRESS_LIB_SOURCES)
 DEPFILES = $(all_sources:.cc=.cc.d)

@@ -24,7 +24,7 @@ The public interface is in `include/`.  Callers should not include or
 rely on the details of any other header files in this package.  Those
 internal APIs may be changed without warning.

-Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/
+Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/ and https://rocksdb.slack.com/

 ## License

@@ -1,4 +1,4 @@
-# This file @generated by `python buckifier/buckify_rocksdb.py`
+# This file @generated by `python3 buckifier/buckify_rocksdb.py`
 # --> DO NOT EDIT MANUALLY <--
 # This file is a Facebook-specific integration for buck builds, so can
 # only be validated by Facebook employees.
@@ -26,7 +26,6 @@ ROCKSDB_EXTERNAL_DEPS = [
    ("lz4", None, "lz4"),
    ("zstd", None),
    ("tbb", None),
-    ("googletest", None, "gtest"),
 ]

 ROCKSDB_OS_DEPS = [
@@ -109,15 +108,25 @@ ROCKSDB_OS_DEPS += ([(
    ["third-party//jemalloc:headers"],
 )] if sanitizer == "" else [])

+ROCKSDB_LIB_DEPS = [
+    ":rocksdb_lib",
+    ":rocksdb_test_lib",
+] if not is_opt_mode else [":rocksdb_lib"]
+
 cpp_library(
    name = "rocksdb_lib",
    srcs = [
+        "cache/cache.cc",
        "cache/clock_cache.cc",
        "cache/lru_cache.cc",
        "cache/sharded_cache.cc",
        "db/arena_wrapped_db_iter.cc",
        "db/blob/blob_file_addition.cc",
        "db/blob/blob_file_garbage.cc",
+        "db/blob/blob_file_meta.cc",
+        "db/blob/blob_log_format.cc",
+        "db/blob/blob_log_reader.cc",
+        "db/blob/blob_log_writer.cc",
        "db/builder.cc",
        "db/c.cc",
        "db/column_family.cc",
@@ -171,6 +180,7 @@ cpp_library(
        "db/trim_history_scheduler.cc",
        "db/version_builder.cc",
        "db/version_edit.cc",
+        "db/version_edit_handler.cc",
        "db/version_set.cc",
        "db/wal_manager.cc",
        "db/write_batch.cc",
@@ -202,6 +212,7 @@ cpp_library(
        "memory/arena.cc",
        "memory/concurrent_arena.cc",
        "memory/jemalloc_nodump_allocator.cc",
+        "memory/memkind_kmem_allocator.cc",
        "memtable/alloc_tracker.cc",
        "memtable/hash_linklist_rep.cc",
        "memtable/hash_skiplist_rep.cc",
@@ -227,7 +238,6 @@ cpp_library(
        "options/options.cc",
        "options/options_helper.cc",
        "options/options_parser.cc",
-        "options/options_sanity_check.cc",
        "port/port_posix.cc",
        "port/stack_trace.cc",
        "table/adaptive/adaptive_table_factory.cc",
@@ -311,9 +321,6 @@ cpp_library(
        "utilities/blob_db/blob_db_impl_filesnapshot.cc",
        "utilities/blob_db/blob_dump_tool.cc",
        "utilities/blob_db/blob_file.cc",
-        "utilities/blob_db/blob_log_format.cc",
-        "utilities/blob_db/blob_log_reader.cc",
-        "utilities/blob_db/blob_log_writer.cc",
        "utilities/cassandra/cassandra_compaction_filter.cc",
        "utilities/cassandra/format.cc",
        "utilities/cassandra/merge_operator.cc",
@@ -391,7 +398,9 @@ cpp_library(
    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
    deps = [":rocksdb_lib"],
-    external_deps = ROCKSDB_EXTERNAL_DEPS,
+    external_deps = ROCKSDB_EXTERNAL_DEPS + [
+        ("googletest", None, "gtest"),
+    ],
 )

 cpp_library(
@@ -434,10 +443,31 @@ cpp_library(
    os_deps = ROCKSDB_OS_DEPS,
    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-    deps = [":rocksdb_lib"],
+    deps = ROCKSDB_LIB_DEPS,
    external_deps = ROCKSDB_EXTERNAL_DEPS,
 )

+if not is_opt_mode:
+    cpp_binary(
+        name = "c_test_bin",
+        srcs = ["db/c_test.c"],
+        arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
+        os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
+        compiler_flags = ROCKSDB_COMPILER_FLAGS,
+        preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
+        deps = [":rocksdb_test_lib"],
+    )
+
+if not is_opt_mode:
+    custom_unittest(
+        "c_test",
+        command = [
+            native.package_name() + "/buckifier/rocks_test_runner.sh",
+            "$(location :{})".format("c_test_bin"),
+        ],
+        type = "simple",
+    )
+
 cpp_library(
    name = "env_basic_test_lib",
    srcs = ["env/env_basic_test.cc"],
@@ -509,6 +539,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "block_based_table_reader_test",
+        "table/block_based/block_based_table_reader_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "block_cache_trace_analyzer_test",
        "tools/block_cache_analyzer/block_cache_trace_analyzer_test.cc",
@@ -523,6 +560,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "block_fetcher_test",
+        "table/block_fetcher_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "block_test",
        "table/block_based/block_test.cc",
@@ -537,13 +581,6 @@ ROCKS_TESTS = [
        [],
        [],
    ],
-    [
-        "c_test",
-        "db/c_test.c",
-        "serial",
-        [],
-        [],
-    ],
    [
        "cache_simulator_test",
        "utilities/simulator_cache/cache_simulator_test.cc",
@@ -929,6 +966,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "db_with_timestamp_compaction_test",
+        "db/db_with_timestamp_compaction_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "db_write_test",
        "db/db_write_test.cc",
@@ -1167,6 +1211,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "memkind_kmem_allocator_test",
+        "memory/memkind_kmem_allocator_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "memory_test",
        "utilities/memory/memory_test.cc",
@@ -1300,6 +1351,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "random_access_file_reader_test",
+        "file/random_access_file_reader_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "random_test",
        "util/random_test.cc",
@@ -1426,6 +1484,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "testutil_test",
+        "test_util/testutil_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "thread_list_test",
        "util/thread_list_test.cc",
@@ -1447,6 +1512,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "timer_test",
+        "util/timer_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "trace_analyzer_test",
        "tools/trace_analyzer_test.cc",
@@ -1454,6 +1526,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "transaction_lock_mgr_test",
+        "utilities/transactions/transaction_lock_mgr_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
    [
        "transaction_test",
        "utilities/transactions/transaction_test.cc",
@@ -1503,6 +1582,13 @@ ROCKS_TESTS = [
        [],
        [],
    ],
+    [
+        "work_queue_test",
+        "util/work_queue_test.cc",
+        "serial",
+        [],
+        [],
+    ],
    [
        "write_batch_test",
        "db/write_batch_test.cc",
@@ -1558,18 +1644,17 @@ ROCKS_TESTS = [
 # Do not build the tests in opt mode, since SyncPoint and other test code
 # will not be included.
 [
-    test_binary(
-        extra_compiler_flags = extra_compiler_flags,
-        extra_deps = extra_deps,
-        parallelism = parallelism,
-        rocksdb_arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-        rocksdb_compiler_flags = ROCKSDB_COMPILER_FLAGS,
-        rocksdb_external_deps = ROCKSDB_EXTERNAL_DEPS,
-        rocksdb_os_deps = ROCKSDB_OS_DEPS,
-        rocksdb_os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-        rocksdb_preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-        test_cc = test_cc,
-        test_name = test_name,
+    cpp_unittest(
+        name = test_name,
+        srcs = [test_cc],
+        arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
+        os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
+        compiler_flags = ROCKSDB_COMPILER_FLAGS,
+        preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
+        deps = [":rocksdb_test_lib"] + extra_deps,
+        external_deps = ROCKSDB_EXTERNAL_DEPS + [
+            ("googletest", None, "gtest"),
+        ],
    )
    for test_name, test_cc, parallelism, extra_deps, extra_compiler_flags in ROCKS_TESTS
    if not is_opt_mode
@@ -106,3 +106,6 @@ LzLabs is using RocksDB as a storage engine in their multi-database distributed
 ## Nebula Graph

 [Nebula Graph](https://github.com/vesoft-inc/nebula) is a distributed, scalable, lightning-fast, open source graph database capable of hosting super large scale graphs with dozens of billions of vertices (nodes) and trillions of edges, with milliseconds of latency.
+
+## YugabyteDB
+[YugabyteDB](https://www.yugabyte.com/) is an open source, high performance, distributed SQL database that uses RocksDB as its storage layer. For more information, please see https://github.com/yugabyte/yugabyte-db/.
@@ -1,6 +1,6 @@
 version: 1.0.{build}

-image: Visual Studio 2017
+image: Visual Studio 2019

 environment:
  JAVA_HOME: C:\Program Files\Java\jdk1.8.0
@@ -24,6 +24,15 @@ environment:
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
      CMAKE_GENERATOR: Visual Studio 15 Win64
      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.com
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      CMAKE_GENERATOR: Visual Studio 16
+      CMAKE_PLATEFORM_NAME: x64
+      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\IDE\devenv.com
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      CMAKE_GENERATOR: Visual Studio 16
+      CMAKE_PLATEFORM_NAME: x64
+      CMAKE_OPT: -DCMAKE_CXX_STANDARD=20
+      DEV_ENV: C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\IDE\devenv.com

 install:
  - md %THIRDPARTY_HOME%
@@ -34,7 +43,8 @@ install:
  - cd snappy-1.1.7
  - mkdir build
  - cd build
-  - cmake -G "%CMAKE_GENERATOR%" ..
+  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
+  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT%
  - msbuild Snappy.sln /p:Configuration=Debug /p:Platform=x64
  - msbuild Snappy.sln /p:Configuration=Release /p:Platform=x64
  - echo "Building LZ4 dependency..."
@@ -57,7 +67,8 @@ install:
 before_build:
  - md %APPVEYOR_BUILD_FOLDER%\build
  - cd %APPVEYOR_BUILD_FOLDER%\build
-  - cmake -G "%CMAKE_GENERATOR%" -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE=1 -DSNAPPY=1 -DLZ4=1 -DZSTD=1 -DXPRESS=1 -DJNI=1 ..
+  - if DEFINED CMAKE_PLATEFORM_NAME (set "PLATEFORM_OPT=-A %CMAKE_PLATEFORM_NAME%")
+  - cmake .. -G "%CMAKE_GENERATOR%" %PLATEFORM_OPT% %CMAKE_OPT% -DCMAKE_BUILD_TYPE=Debug -DOPTDBG=1 -DPORTABLE=1 -DSNAPPY=1 -DLZ4=1 -DZSTD=1 -DXPRESS=1 -DJNI=1
  - cd ..

 build:
@@ -20,10 +20,10 @@ from util import ColorString
 # User can pass extra dependencies as a JSON object via command line, and this
 # script can include these dependencies in the generate TARGETS file.
 # Usage:
-# $python buckifier/buckify_rocksdb.py
+# $python3 buckifier/buckify_rocksdb.py
 # (This generates a TARGET file without user-specified dependency for unit
 # tests.)
-# $python buckifier/buckify_rocksdb.py \
+# $python3 buckifier/buckify_rocksdb.py \
 #        '{"fake": { \
 #                      "extra_deps": [":test_dep", "//fakes/module:mock1"],  \
 #                      "extra_compiler_flags": ["-DROCKSDB_LITE", "-Os"], \
@@ -64,8 +64,6 @@ def get_cc_files(repo_path):
            continue
        for filename in fnmatch.filter(filenames, '*.cc'):
            cc_files.append(os.path.join(root, filename))
-        for filename in fnmatch.filter(filenames, '*.c'):
-            cc_files.append(os.path.join(root, filename))
    return cc_files


@@ -108,7 +106,6 @@ def get_tests(repo_path):

    return tests

-
 # Parse extra dependencies passed by user from command line
 def get_dependencies():
    deps_map = {
@@ -147,6 +144,7 @@ def generate_targets(repo_path, deps_map):
        return False

    TARGETS = TARGETSBuilder("%s/TARGETS" % repo_path)
+
    # rocksdb_lib
    TARGETS.add_library(
        "rocksdb_lib",
@@ -159,7 +157,10 @@ def generate_targets(repo_path, deps_map):
        src_mk.get("TEST_LIB_SOURCES", []) +
        src_mk.get("EXP_LIB_SOURCES", []) +
        src_mk.get("ANALYZER_LIB_SOURCES", []),
-        [":rocksdb_lib"])
+        [":rocksdb_lib"],
+        extra_external_deps=""" + [
+        ("googletest", None, "gtest"),
+    ]""")
    # rocksdb_tools_lib
    TARGETS.add_library(
        "rocksdb_tools_lib",
@@ -168,18 +169,25 @@ def generate_targets(repo_path, deps_map):
        ["test_util/testutil.cc"],
        [":rocksdb_lib"])
    # rocksdb_stress_lib
-    TARGETS.add_library(
+    TARGETS.add_rocksdb_library(
        "rocksdb_stress_lib",
        src_mk.get("ANALYZER_LIB_SOURCES", [])
        + src_mk.get('STRESS_LIB_SOURCES', [])
-        + ["test_util/testutil.cc"],
-        [":rocksdb_lib"])
+        + ["test_util/testutil.cc"])

-    print("Extra dependencies:\n{0}".format(str(deps_map)))
-    # test for every test we found in the Makefile
+    print("Extra dependencies:\n{0}".format(json.dumps(deps_map)))
+
+    # c_test.c is added through TARGETS.add_c_test(). If there
+    # are more than one .c test file, we need to extend
+    # TARGETS.add_c_test() to include other C tests too.
+    TARGETS.add_c_test()
+
+    # test for every .cc test we found in the Makefile
    for target_alias, deps in deps_map.items():
        for test in sorted(tests):
-            match_src = [src for src in cc_files if ("/%s.c" % test) in src]
+            if test == 'c_test':
+                continue
+            match_src = [src for src in cc_files if ("/%s.cc" % test) in src]
            if len(match_src) == 0:
                print(ColorString.warning("Cannot find .cc file for %s" % test))
                continue
@@ -196,8 +204,8 @@ def generate_targets(repo_path, deps_map):
                test_target_name,
                match_src[0],
                is_parallel,
-                deps['extra_deps'],
-                deps['extra_compiler_flags'])
+                json.dumps(deps['extra_deps']),
+                json.dumps(deps['extra_compiler_flags']))

            if test in _EXPORTED_TEST_LIBS:
                test_library = "%s_lib" % test_target_name
@@ -220,6 +228,7 @@ def get_rocksdb_path():

    return rocksdb_path

+
 def exit_with_error(msg):
    print(ColorString.error(msg))
    sys.exit(1)
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+# If clang_format_diff.py command is not specfied, we assume we are able to
+# access directly without any path.
+
+TGT_DIFF=`git diff TARGETS | head -n 1`
+
+if [ ! -z "$TGT_DIFF" ]
+then
+  echo "TARGETS file has uncommitted changes. Skip this check."
+  exit 0
+fi
+
+echo Backup original TARGETS file.
+
+cp TARGETS TARGETS.bkp
+
+${PYTHON:-python3} buckifier/buckify_rocksdb.py
+
+TGT_DIFF=`git diff TARGETS | head -n 1`
+
+if [ -z "$TGT_DIFF" ]
+then
+  mv TARGETS.bkp TARGETS
+  exit 0
+else
+  echo "Please run '${PYTHON:-python3} buckifier/buckify_rocksdb.py' to update TARGETS file."
+  echo "Do not manually update TARGETS file."
+  ${PYTHON:-python3} --version
+  mv TARGETS.bkp TARGETS
+  exit 1
+fi
@@ -28,7 +28,8 @@ class TARGETSBuilder(object):
    def __init__(self, path):
        self.path = path
        self.targets_file = open(path, 'w')
-        self.targets_file.write(targets_cfg.rocksdb_target_header)
+        header = targets_cfg.rocksdb_target_header_template
+        self.targets_file.write(header)
        self.total_lib = 0
        self.total_bin = 0
        self.total_test = 0
@@ -37,17 +38,35 @@ class TARGETSBuilder(object):
    def __del__(self):
        self.targets_file.close()

-    def add_library(self, name, srcs, deps=None, headers=None):
+    def add_library(self, name, srcs, deps=None, headers=None,
+                    extra_external_deps=""):
        headers_attr_prefix = ""
        if headers is None:
            headers_attr_prefix = "auto_"
            headers = "AutoHeaders.RECURSIVE_GLOB"
+        else:
+            headers = "[" + pretty_list(headers) + "]"
        self.targets_file.write(targets_cfg.library_template.format(
            name=name,
            srcs=pretty_list(srcs),
            headers_attr_prefix=headers_attr_prefix,
            headers=headers,
-            deps=pretty_list(deps)))
+            deps=pretty_list(deps),
+            extra_external_deps=extra_external_deps))
+        self.total_lib = self.total_lib + 1
+
+    def add_rocksdb_library(self, name, srcs, headers=None):
+        headers_attr_prefix = ""
+        if headers is None:
+            headers_attr_prefix = "auto_"
+            headers = "AutoHeaders.RECURSIVE_GLOB"
+        else:
+            headers = "[" + pretty_list(headers) + "]"
+        self.targets_file.write(targets_cfg.rocksdb_library_template.format(
+            name=name,
+            srcs=pretty_list(srcs),
+            headers_attr_prefix=headers_attr_prefix,
+            headers=headers))
        self.total_lib = self.total_lib + 1

    def add_binary(self, name, srcs, deps=None):
@@ -57,6 +76,30 @@ class TARGETSBuilder(object):
            pretty_list(deps)))
        self.total_bin = self.total_bin + 1

+    def add_c_test(self):
+        self.targets_file.write("""
+if not is_opt_mode:
+    cpp_binary(
+        name = "c_test_bin",
+        srcs = ["db/c_test.c"],
+        arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
+        os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
+        compiler_flags = ROCKSDB_COMPILER_FLAGS,
+        preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
+        deps = [":rocksdb_test_lib"],
+    )
+
+if not is_opt_mode:
+    custom_unittest(
+        "c_test",
+        command = [
+            native.package_name() + "/buckifier/rocks_test_runner.sh",
+            "$(location :{})".format("c_test_bin"),
+        ],
+        type = "simple",
+    )
+""")
+
    def register_test(self,
                      test_name,
                      src,
@@ -4,7 +4,8 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals

-rocksdb_target_header = """# This file \100generated by `python buckifier/buckify_rocksdb.py`
+rocksdb_target_header_template = \
+    """# This file \100generated by `python3 buckifier/buckify_rocksdb.py`
 # --> DO NOT EDIT MANUALLY <--
 # This file is a Facebook-specific integration for buck builds, so can
 # only be validated by Facebook employees.
@@ -32,7 +33,6 @@ ROCKSDB_EXTERNAL_DEPS = [
    ("lz4", None, "lz4"),
    ("zstd", None),
    ("tbb", None),
-    ("googletest", None, "gtest"),
 ]

 ROCKSDB_OS_DEPS = [
@@ -114,6 +114,11 @@ ROCKSDB_OS_DEPS += ([(
    "linux",
    ["third-party//jemalloc:headers"],
 )] if sanitizer == "" else [])
+
+ROCKSDB_LIB_DEPS = [
+    ":rocksdb_lib",
+    ":rocksdb_test_lib",
+] if not is_opt_mode else [":rocksdb_lib"]
 """


@@ -128,6 +133,21 @@ cpp_library(
    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
    deps = [{deps}],
+    external_deps = ROCKSDB_EXTERNAL_DEPS{extra_external_deps},
+)
+"""
+
+rocksdb_library_template = """
+cpp_library(
+    name = "{name}",
+    srcs = [{srcs}],
+    {headers_attr_prefix}headers = {headers},
+    arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
+    compiler_flags = ROCKSDB_COMPILER_FLAGS,
+    os_deps = ROCKSDB_OS_DEPS,
+    os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
+    preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
+    deps = ROCKSDB_LIB_DEPS,
    external_deps = ROCKSDB_EXTERNAL_DEPS,
 )
 """
@@ -162,18 +182,17 @@ ROCKS_TESTS = [
 # Do not build the tests in opt mode, since SyncPoint and other test code
 # will not be included.
 [
-    test_binary(
-        extra_compiler_flags = extra_compiler_flags,
-        extra_deps = extra_deps,
-        parallelism = parallelism,
-        rocksdb_arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
-        rocksdb_compiler_flags = ROCKSDB_COMPILER_FLAGS,
-        rocksdb_external_deps = ROCKSDB_EXTERNAL_DEPS,
-        rocksdb_os_deps = ROCKSDB_OS_DEPS,
-        rocksdb_os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
-        rocksdb_preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
-        test_cc = test_cc,
-        test_name = test_name,
+    cpp_unittest(
+        name = test_name,
+        srcs = [test_cc],
+        arch_preprocessor_flags = ROCKSDB_ARCH_PREPROCESSOR_FLAGS,
+        os_preprocessor_flags = ROCKSDB_OS_PREPROCESSOR_FLAGS,
+        compiler_flags = ROCKSDB_COMPILER_FLAGS,
+        preprocessor_flags = ROCKSDB_PREPROCESSOR_FLAGS,
+        deps = [":rocksdb_test_lib"] + extra_deps,
+        external_deps = ROCKSDB_EXTERNAL_DEPS + [
+            ("googletest", None, "gtest"),
+        ],
    )
    for test_name, test_cc, parallelism, extra_deps, extra_compiler_flags in ROCKS_TESTS
    if not is_opt_mode
@@ -28,6 +28,7 @@
 #       -DZSTD                      if the ZSTD library is present
 #       -DNUMA                      if the NUMA library is present
 #       -DTBB                       if the TBB library is present
+#       -DMEMKIND                   if the memkind library is present
 #
 # Using gflags in rocksdb:
 # Our project depends on gflags, which requires users to take some extra steps
@@ -245,6 +246,10 @@ JAVAC_ARGS="-source 7"
 if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
    # Cross-compiling; do not try any compilation tests.
    # Also don't need any compilation tests if compiling on fbcode
+    if [ "$FBCODE_BUILD" = "true" ]; then
+      # Enable backtrace on fbcode since the necessary libraries are present
+      COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_BACKTRACE"
+    fi
    true
 else
    if ! test $ROCKSDB_DISABLE_FALLOCATE; then
@@ -425,7 +430,23 @@ EOF
            COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_MALLOC_USABLE_SIZE"
        fi
    fi
-
+    
+    if ! test $ROCKSDB_DISABLE_MEMKIND; then
+        # Test whether memkind library is installed
+        $CXX $CFLAGS $COMMON_FLAGS -lmemkind -x c++ - -o /dev/null 2>/dev/null  <<EOF
+          #include <memkind.h>
+          int main() {
+            memkind_malloc(MEMKIND_DAX_KMEM, 1024);
+            return 0;
+          }
+EOF
+        if [ "$?" = 0 ]; then
+            COMMON_FLAGS="$COMMON_FLAGS -DMEMKIND"
+            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lmemkind"
+            JAVA_LDFLAGS="$JAVA_LDFLAGS -lmemkind"
+        fi
+    fi
+    
    if ! test $ROCKSDB_DISABLE_PTHREAD_MUTEX_ADAPTIVE_NP; then
        # Test whether PTHREAD_MUTEX_ADAPTIVE_NP mutex type is available
        $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
@@ -684,6 +705,7 @@ EOF
  fi
 fi

+
 if [ "$FBCODE_BUILD" != "true" -a "$PLATFORM" = OS_LINUX ]; then
  $CXX $COMMON_FLAGS $PLATFORM_SHARED_CFLAGS -x c++ -c - -o test_dl.o 2>/dev/null <<EOF
  void dummy_func() {}
@@ -2,41 +2,99 @@
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
 # If clang_format_diff.py command is not specfied, we assume we are able to
 # access directly without any path.
-if [ -z $CLANG_FORMAT_DIFF ]
-then
-CLANG_FORMAT_DIFF="clang-format-diff.py"
-fi

-# Check clang-format-diff.py
-if ! which $CLANG_FORMAT_DIFF &> /dev/null
-then
-  echo "You didn't have clang-format-diff.py and/or clang-format available in your computer!"
-  echo "You can download clang-format-diff.py by running: "
-  echo "    curl --location http://goo.gl/iUW1u2 -o ${CLANG_FORMAT_DIFF}"
-  echo "You can download clang-format by running:"
-  echo "    brew install clang-format"
-  echo "  Or"
-  echo "    apt install clang-format"
-  echo "  This might work too:"
-  echo "    yum install git-clang-format"
-  echo "Then, move both files (i.e. ${CLANG_FORMAT_DIFF} and clang-format) to some directory within PATH=${PATH}"
-  echo "and make sure ${CLANG_FORMAT_DIFF} is executable."
-  exit 128
-fi
+print_usage () {
+  echo "Usage:"
+  echo "format-diff.sh [OPTIONS]"
+  echo "-c: check only."
+  echo "-h: print this message."
+}

-# Check argparse, a library that clang-format-diff.py requires.
-python 2>/dev/null << EOF
-import argparse
-EOF
+while getopts ':ch' OPTION; do
+  case "$OPTION" in
+    c)
+      CHECK_ONLY=1
+      ;;
+    h)
+      print_usage
+      exit 1
+      ;;
+    ?)
+      print_usage
+      exit 1
+      ;;
+  esac
+done

-if [ "$?" != 0 ]
-then
-  echo "To run clang-format-diff.py, we'll need the library "argparse" to be"
-  echo "installed. You can try either of the follow ways to install it:"
-  echo "  1. Manually download argparse: https://pypi.python.org/pypi/argparse"
-  echo "  2. easy_install argparse (if you have easy_install)"
-  echo "  3. pip install argparse (if you have pip)"
-  exit 129
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+
+if [ "$CLANG_FORMAT_DIFF" ]; then
+  echo "Note: CLANG_FORMAT_DIFF='$CLANG_FORMAT_DIFF'"
+  # Dry run to confirm dependencies like argparse
+  if $CLANG_FORMAT_DIFF --help >/dev/null < /dev/null; then
+    true #Good
+  else
+    exit 128
+  fi
+else
+  # First try directly executing the possibilities
+  if clang-format-diff.py --help &> /dev/null < /dev/null; then
+    CLANG_FORMAT_DIFF=clang-format-diff.py
+  elif $REPO_ROOT/clang-format-diff.py --help &> /dev/null < /dev/null; then
+    CLANG_FORMAT_DIFF=$REPO_ROOT/clang-format-diff.py
+  else
+    # This probably means we need to directly invoke the interpreter.
+    # But first find clang-format-diff.py
+    if [ -f "$REPO_ROOT/clang-format-diff.py" ]; then
+      CFD_PATH="$REPO_ROOT/clang-format-diff.py"
+    elif which clang-format-diff.py &> /dev/null; then
+      CFD_PATH="$(which clang-format-diff.py)"
+    else
+      echo "You didn't have clang-format-diff.py and/or clang-format available in your computer!"
+      echo "You can download clang-format-diff.py by running: "
+      echo "    curl --location http://goo.gl/iUW1u2 -o ${CLANG_FORMAT_DIFF}"
+      echo "You can download clang-format by running:"
+      echo "    brew install clang-format"
+      echo "  Or"
+      echo "    apt install clang-format"
+      echo "  This might work too:"
+      echo "    yum install git-clang-format"
+      echo "Then, move both files (i.e. ${CLANG_FORMAT_DIFF} and clang-format) to some directory within PATH=${PATH}"
+      echo "and make sure ${CLANG_FORMAT_DIFF} is executable."
+      exit 128
+    fi
+    # Check argparse pre-req on interpreter, or it will fail
+    if echo import argparse | ${PYTHON:-python3}; then
+      true # Good
+    else
+      echo "To run clang-format-diff.py, we'll need the library "argparse" to be"
+      echo "installed. You can try either of the follow ways to install it:"
+      echo "  1. Manually download argparse: https://pypi.python.org/pypi/argparse"
+      echo "  2. easy_install argparse (if you have easy_install)"
+      echo "  3. pip install argparse (if you have pip)"
+      exit 129
+    fi
+    # Unfortunately, some machines have a Python2 clang-format-diff.py
+    # installed but only a Python3 interpreter installed. Rather than trying
+    # different Python versions that might be installed, we can try migrating
+    # the code to Python3 if it looks like Python2
+    if grep -q "print '" "$CFD_PATH" && \
+       ${PYTHON:-python3} --version | grep -q 'ython 3'; then
+      if [ ! -f "$REPO_ROOT/.py3/clang-format-diff.py" ]; then
+        echo "Migrating $CFD_PATH to Python3 in a hidden file"
+        mkdir -p "$REPO_ROOT/.py3"
+        ${PYTHON:-python3} -m lib2to3 -w -n -o "$REPO_ROOT/.py3" "$CFD_PATH" > /dev/null || exit 128
+      fi
+      CFD_PATH="$REPO_ROOT/.py3/clang-format-diff.py"
+    fi
+    CLANG_FORMAT_DIFF="${PYTHON:-python3} $CFD_PATH"
+    # This had better work after all those checks
+    if $CLANG_FORMAT_DIFF --help >/dev/null < /dev/null; then
+      true #Good
+    else
+      exit 128
+    fi
+  fi
 fi

 # TODO(kailiu) following work is not complete since we still need to figure
@@ -87,6 +145,14 @@ if [ -z "$diffs" ]
 then
  echo "Nothing needs to be reformatted!"
  exit 0
+elif [ $CHECK_ONLY ]
+then
+  echo "Your change has unformatted code. Please run make format!"
+  if [ $VERBOSE_CHECK ]; then
+    clang-format --version
+    echo "$diffs"
+  fi
+  exit 1
 fi

 # Highlight the insertion/deletion from the clang-format-diff.py's output
@@ -121,7 +187,7 @@ if [ -z "$uncommitted_code" ]
 then
  git diff -U0 "$FORMAT_UPSTREAM_MERGE_BASE" | $CLANG_FORMAT_DIFF -i -p 1
 else
-  git diff -U0 HEAD^ | $CLANG_FORMAT_DIFF -i -p 1
+  git diff -U0 HEAD | $CLANG_FORMAT_DIFF -i -p 1
 fi
 echo "Files reformatted!"

@@ -818,6 +818,8 @@ run_format_compatible()
  rm -rf /dev/shm/rocksdb
  mkdir /dev/shm/rocksdb

+  export https_proxy="fwdproxy:8080"
+  
  tools/check_format_compatible.sh
 }

@@ -1,9 +1,9 @@
 #!/bin/bash
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
-set -e
+set -ex

-ROCKSDB_VERSION="5.10.3"
-ZSTD_VERSION="1.1.3"
+ROCKSDB_VERSION="6.7.3"
+ZSTD_VERSION="1.4.4"

 echo "This script configures CentOS with everything needed to build and run RocksDB"

@@ -40,5 +40,6 @@ cd /usr/local/rocksdb
 chown -R vagrant:vagrant /usr/local/rocksdb/
 sudo -u vagrant make static_lib
 cd examples/
-sudo -u vagrant make all
-sudo -u vagrant ./c_simple_example
+sudo -u vagrant LD_LIBRARY_PATH=/usr/local/lib/ make all
+sudo -u vagrant LD_LIBRARY_PATH=/usr/local/lib/ ./c_simple_example
+
@@ -0,0 +1,66 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "rocksdb/cache.h"
+
+#include "cache/lru_cache.h"
+#include "options/options_helper.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+#ifndef ROCKSDB_LITE
+static std::unordered_map<std::string, OptionTypeInfo>
+    lru_cache_options_type_info = {
+        {"capacity",
+         {offsetof(struct LRUCacheOptions, capacity), OptionType::kSizeT,
+          OptionVerificationType::kNormal, OptionTypeFlags::kMutable,
+          offsetof(struct LRUCacheOptions, capacity)}},
+        {"num_shard_bits",
+         {offsetof(struct LRUCacheOptions, num_shard_bits), OptionType::kInt,
+          OptionVerificationType::kNormal, OptionTypeFlags::kMutable,
+          offsetof(struct LRUCacheOptions, num_shard_bits)}},
+        {"strict_capacity_limit",
+         {offsetof(struct LRUCacheOptions, strict_capacity_limit),
+          OptionType::kBoolean, OptionVerificationType::kNormal,
+          OptionTypeFlags::kMutable,
+          offsetof(struct LRUCacheOptions, strict_capacity_limit)}},
+        {"high_pri_pool_ratio",
+         {offsetof(struct LRUCacheOptions, high_pri_pool_ratio),
+          OptionType::kDouble, OptionVerificationType::kNormal,
+          OptionTypeFlags::kMutable,
+          offsetof(struct LRUCacheOptions, high_pri_pool_ratio)}}};
+#endif  // ROCKSDB_LITE
+
+Status Cache::CreateFromString(const ConfigOptions& config_options,
+                               const std::string& value,
+                               std::shared_ptr<Cache>* result) {
+  Status status;
+  std::shared_ptr<Cache> cache;
+  if (value.find('=') == std::string::npos) {
+    cache = NewLRUCache(ParseSizeT(value));
+  } else {
+#ifndef ROCKSDB_LITE
+    LRUCacheOptions cache_opts;
+    status = OptionTypeInfo::ParseStruct(
+        config_options, "", &lru_cache_options_type_info, "", value,
+        reinterpret_cast<char*>(&cache_opts));
+    if (status.ok()) {
+      cache = NewLRUCache(cache_opts);
+    }
+#else
+    (void)config_options;
+    status = Status::NotSupported("Cannot load cache in LITE mode ", value);
+#endif  //! ROCKSDB_LITE
+  }
+  if (status.ok()) {
+    result->swap(cache);
+  }
+  return status;
+}
+}  // namespace ROCKSDB_NAMESPACE
@@ -14,34 +14,47 @@ int main() {
 #include <stdio.h>
 #include <sys/types.h>
 #include <cinttypes>
+#include <limits>

 #include "port/port.h"
 #include "rocksdb/cache.h"
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
+#include "util/coding.h"
 #include "util/gflags_compat.h"
+#include "util/hash.h"
 #include "util/mutexlock.h"
 #include "util/random.h"

 using GFLAGS_NAMESPACE::ParseCommandLineFlags;

-static const uint32_t KB = 1024;
+static constexpr uint32_t KiB = uint32_t{1} << 10;
+static constexpr uint32_t MiB = KiB << 10;
+static constexpr uint64_t GiB = MiB << 10;

-DEFINE_int32(threads, 16, "Number of concurrent threads to run.");
-DEFINE_int64(cache_size, 8 * KB * KB,
-             "Number of bytes to use as a cache of uncompressed data.");
-DEFINE_int32(num_shard_bits, 4, "shard_bits.");
+DEFINE_uint32(threads, 16, "Number of concurrent threads to run.");
+DEFINE_uint64(cache_size, 1 * GiB,
+              "Number of bytes to use as a cache of uncompressed data.");
+DEFINE_uint32(num_shard_bits, 6, "shard_bits.");

-DEFINE_int64(max_key, 1 * KB * KB * KB, "Max number of key to place in cache");
-DEFINE_uint64(ops_per_thread, 1200000, "Number of operations per thread.");
+DEFINE_double(resident_ratio, 0.25,
+              "Ratio of keys fitting in cache to keyspace.");
+DEFINE_uint64(ops_per_thread, 0,
+              "Number of operations per thread. (Default: 5 * keyspace size)");
+DEFINE_uint32(value_bytes, 8 * KiB, "Size of each value added.");

-DEFINE_bool(populate_cache, false, "Populate cache before operations");
-DEFINE_int32(insert_percent, 40,
-             "Ratio of insert to total workload (expressed as a percentage)");
-DEFINE_int32(lookup_percent, 50,
-             "Ratio of lookup to total workload (expressed as a percentage)");
-DEFINE_int32(erase_percent, 10,
-             "Ratio of erase to total workload (expressed as a percentage)");
+DEFINE_uint32(skew, 5, "Degree of skew in key selection");
+DEFINE_bool(populate_cache, true, "Populate cache before operations");
+
+DEFINE_uint32(lookup_insert_percent, 87,
+              "Ratio of lookup (+ insert on not found) to total workload "
+              "(expressed as a percentage)");
+DEFINE_uint32(insert_percent, 2,
+              "Ratio of insert to total workload (expressed as a percentage)");
+DEFINE_uint32(lookup_percent, 10,
+              "Ratio of lookup to total workload (expressed as a percentage)");
+DEFINE_uint32(erase_percent, 1,
+              "Ratio of erase to total workload (expressed as a percentage)");

 DEFINE_bool(use_clock_cache, false, "");

@@ -49,21 +62,15 @@ namespace ROCKSDB_NAMESPACE {

 class CacheBench;
 namespace {
-void deleter(const Slice& /*key*/, void* value) {
-    delete reinterpret_cast<char *>(value);
-}
-
 // State shared by all concurrent executions of the same benchmark.
 class SharedState {
 public:
  explicit SharedState(CacheBench* cache_bench)
      : cv_(&mu_),
-        num_threads_(FLAGS_threads),
        num_initialized_(0),
        start_(false),
        num_done_(0),
-        cache_bench_(cache_bench) {
-  }
+        cache_bench_(cache_bench) {}

  ~SharedState() {}

@@ -87,13 +94,9 @@ class SharedState {
    num_done_++;
  }

-  bool AllInitialized() const {
-    return num_initialized_ >= num_threads_;
-  }
+  bool AllInitialized() const { return num_initialized_ >= FLAGS_threads; }

-  bool AllDone() const {
-    return num_done_ >= num_threads_;
-  }
+  bool AllDone() const { return num_done_ >= FLAGS_threads; }

  void SetStart() {
    start_ = true;
@@ -107,7 +110,6 @@ class SharedState {
  port::Mutex mu_;
  port::CondVar cv_;

-  const uint64_t num_threads_;
  uint64_t num_initialized_;
  bool start_;
  uint64_t num_done_;
@@ -118,17 +120,69 @@ class SharedState {
 // Per-thread state for concurrent executions of the same benchmark.
 struct ThreadState {
  uint32_t tid;
-  Random rnd;
+  Random64 rnd;
  SharedState* shared;

  ThreadState(uint32_t index, SharedState* _shared)
      : tid(index), rnd(1000 + index), shared(_shared) {}
 };
+
+struct KeyGen {
+  char key_data[27];
+
+  Slice GetRand(Random64& rnd, uint64_t max_key) {
+    uint64_t raw = rnd.Next();
+    // Skew according to setting
+    for (uint32_t i = 0; i < FLAGS_skew; ++i) {
+      raw = std::min(raw, rnd.Next());
+    }
+    uint64_t key = fastrange64(raw, max_key);
+    // Variable size and alignment
+    size_t off = key % 8;
+    key_data[0] = char{42};
+    EncodeFixed64(key_data + 1, key);
+    key_data[9] = char{11};
+    EncodeFixed64(key_data + 10, key);
+    key_data[18] = char{4};
+    EncodeFixed64(key_data + 19, key);
+    return Slice(&key_data[off], sizeof(key_data) - off);
+  }
+};
+
+char* createValue(Random64& rnd) {
+  char* rv = new char[FLAGS_value_bytes];
+  // Fill with some filler data, and take some CPU time
+  for (uint32_t i = 0; i < FLAGS_value_bytes; i += 8) {
+    EncodeFixed64(rv + i, rnd.Next());
+  }
+  return rv;
+}
+
+void deleter(const Slice& /*key*/, void* value) {
+  delete[] static_cast<char*>(value);
+}
 }  // namespace

 class CacheBench {
+  static constexpr uint64_t kHundredthUint64 =
+      std::numeric_limits<uint64_t>::max() / 100U;
+
 public:
-  CacheBench() : num_threads_(FLAGS_threads) {
+  CacheBench()
+      : max_key_(static_cast<uint64_t>(FLAGS_cache_size / FLAGS_resident_ratio /
+                                       FLAGS_value_bytes)),
+        lookup_insert_threshold_(kHundredthUint64 *
+                                 FLAGS_lookup_insert_percent),
+        insert_threshold_(lookup_insert_threshold_ +
+                          kHundredthUint64 * FLAGS_insert_percent),
+        lookup_threshold_(insert_threshold_ +
+                          kHundredthUint64 * FLAGS_lookup_percent),
+        erase_threshold_(lookup_threshold_ +
+                         kHundredthUint64 * FLAGS_erase_percent) {
+    if (erase_threshold_ != 100U * kHundredthUint64) {
+      fprintf(stderr, "Percentages must add to 100.\n");
+      exit(1);
+    }
    if (FLAGS_use_clock_cache) {
      cache_ = NewClockCache(FLAGS_cache_size, FLAGS_num_shard_bits);
      if (!cache_) {
@@ -138,18 +192,19 @@ class CacheBench {
    } else {
      cache_ = NewLRUCache(FLAGS_cache_size, FLAGS_num_shard_bits);
    }
+    if (FLAGS_ops_per_thread == 0) {
+      FLAGS_ops_per_thread = 5 * max_key_;
+    }
  }

  ~CacheBench() {}

  void PopulateCache() {
-    Random rnd(1);
-    for (int64_t i = 0; i < FLAGS_cache_size; i++) {
-      uint64_t rand_key = rnd.Next() % FLAGS_max_key;
-      // Cast uint64* to be char*, data would be copied to cache
-      Slice key(reinterpret_cast<char*>(&rand_key), 8);
-      // do insert
-      cache_->Insert(key, new char[10], 1, &deleter);
+    Random64 rnd(1);
+    KeyGen keygen;
+    for (uint64_t i = 0; i < 2 * FLAGS_cache_size; i += FLAGS_value_bytes) {
+      cache_->Insert(keygen.GetRand(rnd, max_key_), createValue(rnd),
+                     FLAGS_value_bytes, &deleter);
    }
  }

@@ -158,10 +213,10 @@ class CacheBench {

    PrintEnv();
    SharedState shared(this);
-    std::vector<ThreadState*> threads(num_threads_);
-    for (uint32_t i = 0; i < num_threads_; i++) {
-      threads[i] = new ThreadState(i, &shared);
-      env->StartThread(ThreadBody, threads[i]);
+    std::vector<std::unique_ptr<ThreadState> > threads(FLAGS_threads);
+    for (uint32_t i = 0; i < FLAGS_threads; i++) {
+      threads[i].reset(new ThreadState(i, &shared));
+      env->StartThread(ThreadBody, threads[i].get());
    }
    {
      MutexLock l(shared.GetMutex());
@@ -192,10 +247,15 @@ class CacheBench {

 private:
  std::shared_ptr<Cache> cache_;
-  uint32_t num_threads_;
+  const uint64_t max_key_;
+  // Cumulative thresholds in the space of a random uint64_t
+  const uint64_t lookup_insert_threshold_;
+  const uint64_t insert_threshold_;
+  const uint64_t lookup_threshold_;
+  const uint64_t erase_threshold_;

  static void ThreadBody(void* v) {
-    ThreadState* thread = reinterpret_cast<ThreadState*>(v);
+    ThreadState* thread = static_cast<ThreadState*>(v);
    SharedState* shared = thread->shared;

    {
@@ -220,40 +280,78 @@ class CacheBench {
  }

  void OperateCache(ThreadState* thread) {
+    // To use looked-up values
+    uint64_t result = 0;
+    // To hold handles for a non-trivial amount of time
+    Cache::Handle* handle = nullptr;
+    KeyGen gen;
    for (uint64_t i = 0; i < FLAGS_ops_per_thread; i++) {
-      uint64_t rand_key = thread->rnd.Next() % FLAGS_max_key;
-      // Cast uint64* to be char*, data would be copied to cache
-      Slice key(reinterpret_cast<char*>(&rand_key), 8);
-      int32_t prob_op = thread->rnd.Uniform(100);
-      if (prob_op >= 0 && prob_op < FLAGS_insert_percent) {
-        // do insert
-        cache_->Insert(key, new char[10], 1, &deleter);
-      } else if (prob_op -= FLAGS_insert_percent &&
-                 prob_op < FLAGS_lookup_percent) {
-        // do lookup
-        auto handle = cache_->Lookup(key);
+      Slice key = gen.GetRand(thread->rnd, max_key_);
+      uint64_t random_op = thread->rnd.Next();
+      if (random_op < lookup_insert_threshold_) {
        if (handle) {
          cache_->Release(handle);
+          handle = nullptr;
        }
-      } else if (prob_op -= FLAGS_lookup_percent &&
-                 prob_op < FLAGS_erase_percent) {
+        // do lookup
+        handle = cache_->Lookup(key);
+        if (handle) {
+          // do something with the data
+          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
+                             FLAGS_value_bytes);
+        } else {
+          // do insert
+          cache_->Insert(key, createValue(thread->rnd), FLAGS_value_bytes,
+                         &deleter, &handle);
+        }
+      } else if (random_op < insert_threshold_) {
+        if (handle) {
+          cache_->Release(handle);
+          handle = nullptr;
+        }
+        // do insert
+        cache_->Insert(key, createValue(thread->rnd), FLAGS_value_bytes,
+                       &deleter, &handle);
+      } else if (random_op < lookup_threshold_) {
+        if (handle) {
+          cache_->Release(handle);
+          handle = nullptr;
+        }
+        // do lookup
+        handle = cache_->Lookup(key);
+        if (handle) {
+          // do something with the data
+          result += NPHash64(static_cast<char*>(cache_->Value(handle)),
+                             FLAGS_value_bytes);
+        }
+      } else if (random_op < erase_threshold_) {
        // do erase
        cache_->Erase(key);
+      } else {
+        // Should be extremely unlikely (noop)
+        assert(random_op >= kHundredthUint64 * 100U);
      }
    }
+    if (handle) {
+      cache_->Release(handle);
+      handle = nullptr;
+    }
  }

  void PrintEnv() const {
    printf("RocksDB version     : %d.%d\n", kMajorVersion, kMinorVersion);
-    printf("Number of threads   : %d\n", FLAGS_threads);
+    printf("Number of threads   : %u\n", FLAGS_threads);
    printf("Ops per thread      : %" PRIu64 "\n", FLAGS_ops_per_thread);
    printf("Cache size          : %" PRIu64 "\n", FLAGS_cache_size);
-    printf("Num shard bits      : %d\n", FLAGS_num_shard_bits);
-    printf("Max key             : %" PRIu64 "\n", FLAGS_max_key);
-    printf("Populate cache      : %d\n", FLAGS_populate_cache);
-    printf("Insert percentage   : %d%%\n", FLAGS_insert_percent);
-    printf("Lookup percentage   : %d%%\n", FLAGS_lookup_percent);
-    printf("Erase percentage    : %d%%\n", FLAGS_erase_percent);
+    printf("Num shard bits      : %u\n", FLAGS_num_shard_bits);
+    printf("Max key             : %" PRIu64 "\n", max_key_);
+    printf("Resident ratio      : %g\n", FLAGS_resident_ratio);
+    printf("Skew degree         : %u\n", FLAGS_skew);
+    printf("Populate cache      : %d\n", int{FLAGS_populate_cache});
+    printf("Lookup+Insert pct   : %u%%\n", FLAGS_lookup_insert_percent);
+    printf("Insert percentage   : %u%%\n", FLAGS_insert_percent);
+    printf("Lookup percentage   : %u%%\n", FLAGS_lookup_percent);
+    printf("Erase percentage    : %u%%\n", FLAGS_erase_percent);
    printf("----------------------------\n");
  }
 };
@@ -270,6 +368,8 @@ int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::CacheBench bench;
  if (FLAGS_populate_cache) {
    bench.PopulateCache();
+    printf("Population complete\n");
+    printf("----------------------------\n");
  }
  if (bench.Run()) {
    return 0;
@@ -182,7 +182,7 @@ struct CacheHandle {
  void (*deleter)(const Slice&, void* value);

  // Flags and counters associated with the cache handle:
-  //   lowest bit: n-cache bit
+  //   lowest bit: in-cache bit
  //   second lowest bit: usage bit
  //   the rest bits: reference count
  // The handle is unused when flags equals to 0. The thread decreases the count
@@ -341,7 +341,8 @@ class ClockCacheShard final : public CacheShard {
  CacheHandle* Insert(const Slice& key, uint32_t hash, void* value,
                      size_t change,
                      void (*deleter)(const Slice& key, void* value),
-                      bool hold_reference, CleanupContext* context);
+                      bool hold_reference, CleanupContext* context,
+                      bool* overwritten);

  // Guards list_, head_, and recycle_. In addition, updating table_ also has
  // to hold the mutex, to avoid the cache being in inconsistent state.
@@ -564,7 +565,8 @@ void ClockCacheShard::SetStrictCapacityLimit(bool strict_capacity_limit) {
 CacheHandle* ClockCacheShard::Insert(
    const Slice& key, uint32_t hash, void* value, size_t charge,
    void (*deleter)(const Slice& key, void* value), bool hold_reference,
-    CleanupContext* context) {
+    CleanupContext* context, bool* overwritten) {
+  assert(overwritten != nullptr && *overwritten == false);
  size_t total_charge =
      CacheHandle::CalcTotalCharge(key, charge, metadata_charge_policy_);
  MutexLock l(&mutex_);
@@ -597,6 +599,7 @@ CacheHandle* ClockCacheShard::Insert(
  handle->flags.store(flags, std::memory_order_relaxed);
  HashTable::accessor accessor;
  if (table_.find(accessor, CacheKey(key, hash))) {
+    *overwritten = true;
    CacheHandle* existing_handle = accessor->second;
    table_.erase(accessor);
    UnsetInCache(existing_handle, context);
@@ -619,8 +622,9 @@ Status ClockCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
  char* key_data = new char[key.size()];
  memcpy(key_data, key.data(), key.size());
  Slice key_copy(key_data, key.size());
+  bool overwritten = false;
  CacheHandle* handle = Insert(key_copy, hash, value, charge, deleter,
-                               out_handle != nullptr, &context);
+                               out_handle != nullptr, &context, &overwritten);
  Status s;
  if (out_handle != nullptr) {
    if (handle == nullptr) {
@@ -629,6 +633,10 @@ Status ClockCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
      *out_handle = reinterpret_cast<Cache::Handle*>(handle);
    }
  }
+  if (overwritten) {
+    assert(s.ok());
+    s = Status::OkOverwritten();
+  }
  Cleanup(context);
  return s;
 }
@@ -386,6 +386,7 @@ Status LRUCacheShard::Insert(const Slice& key, uint32_t hash, void* value,
      LRUHandle* old = table_.Insert(e);
      usage_ += total_charge;
      if (old != nullptr) {
+        s = Status::OkOverwritten();
        assert(old->InCache());
        old->SetInCache(false);
        if (!old->HasRefs()) {
@@ -1,3 +1,54 @@
@PACKAGE_INIT@
+
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/modules")
+
+include(CMakeFindDependencyMacro)
+
+set(GFLAGS_USE_TARGET_NAMESPACE @GFLAGS_USE_TARGET_NAMESPACE@)
+
+if(@WITH_JEMALLOC@)
+  find_dependency(JeMalloc)
+endif()
+
+if(@WITH_GFLAGS@)
+  find_dependency(gflags CONFIG)
+  if(NOT gflags_FOUND)
+    find_dependency(gflags)
+  endif()
+endif()
+
+if(@WITH_SNAPPY@)
+  find_dependency(Snappy CONFIG)
+  if(NOT Snappy_FOUND)
+    find_dependency(Snappy)
+  endif()
+endif()
+
+if(@WITH_ZLIB@)
+  find_dependency(ZLIB)
+endif()
+
+if(@WITH_BZ2@)
+  find_dependency(BZip2)
+endif()
+
+if(@WITH_LZ4@)
+  find_dependency(lz4)
+endif()
+
+if(@WITH_ZSTD@)
+  find_dependency(zstd)
+endif()
+
+if(@WITH_NUMA@)
+  find_dependency(NUMA)
+endif()
+
+if(@WITH_TBB@)
+  find_dependency(TBB)
+endif()
+
+find_dependency(Threads)
+
 include("${CMAKE_CURRENT_LIST_DIR}/RocksDBTargets.cmake")
 check_required_components(RocksDB)
@@ -0,0 +1,7 @@
+macro(get_cxx_std_flags FLAGS_VARIABLE)
+  if( CMAKE_CXX_STANDARD_REQUIRED )
+    set(${FLAGS_VARIABLE} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION})
+  else()
+    set(${FLAGS_VARIABLE} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_EXTENSION_COMPILE_OPTION})
+  endif()
+endmacro()
@@ -0,0 +1,29 @@
+# - Find Snappy
+# Find the snappy compression library and includes
+#
+# Snappy_INCLUDE_DIRS - where to find snappy.h, etc.
+# Snappy_LIBRARIES - List of libraries when using snappy.
+# Snappy_FOUND - True if snappy found.
+
+find_path(Snappy_INCLUDE_DIRS
+  NAMES snappy.h
+  HINTS ${snappy_ROOT_DIR}/include)
+
+find_library(Snappy_LIBRARIES
+  NAMES snappy
+  HINTS ${snappy_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Snappy DEFAULT_MSG Snappy_LIBRARIES Snappy_INCLUDE_DIRS)
+
+mark_as_advanced(
+  Snappy_LIBRARIES
+  Snappy_INCLUDE_DIRS)
+
+if(Snappy_FOUND AND NOT (TARGET Snappy::snappy))
+  add_library (Snappy::snappy UNKNOWN IMPORTED)
+  set_target_properties(Snappy::snappy
+    PROPERTIES
+      IMPORTED_LOCATION ${Snappy_LIBRARIES}
+      INTERFACE_INCLUDE_DIRECTORIES ${Snappy_INCLUDE_DIRS})
+endif()
@@ -1,8 +1,8 @@
 # - Find gflags library
 # Find the gflags includes and library
 #
-# gflags_INCLUDE_DIR - where to find gflags.h.
-# gflags_LIBRARIES - List of libraries when using gflags.
+# GFLAGS_INCLUDE_DIR - where to find gflags.h.
+# GFLAGS_LIBRARIES - List of libraries when using gflags.
 # gflags_FOUND - True if gflags found.

 find_path(GFLAGS_INCLUDE_DIR
@@ -1,29 +0,0 @@
-# - Find Snappy
-# Find the snappy compression library and includes
-#
-# snappy_INCLUDE_DIRS - where to find snappy.h, etc.
-# snappy_LIBRARIES - List of libraries when using snappy.
-# snappy_FOUND - True if snappy found.
-
-find_path(snappy_INCLUDE_DIRS
-  NAMES snappy.h
-  HINTS ${snappy_ROOT_DIR}/include)
-
-find_library(snappy_LIBRARIES
-  NAMES snappy
-  HINTS ${snappy_ROOT_DIR}/lib)
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(snappy DEFAULT_MSG snappy_LIBRARIES snappy_INCLUDE_DIRS)
-
-mark_as_advanced(
-  snappy_LIBRARIES
-  snappy_INCLUDE_DIRS)
-
-if(snappy_FOUND AND NOT (TARGET snappy::snappy))
-  add_library (snappy::snappy UNKNOWN IMPORTED)
-  set_target_properties(snappy::snappy
-    PROPERTIES
-      IMPORTED_LOCATION ${snappy_LIBRARIES}
-      INTERFACE_INCLUDE_DIRECTORIES ${snappy_INCLUDE_DIRS})
-endif()
@@ -12,21 +12,24 @@ fi
 ROOT=".."
 # Fetch right version of gcov
 if [ -d /mnt/gvfs/third-party -a -z "$CXX" ]; then
-  source $ROOT/build_tools/fbcode_config.sh
+  source $ROOT/build_tools/fbcode_config_platform007.sh
  GCOV=$GCC_BASE/bin/gcov
 else
  GCOV=$(which gcov)
 fi
+echo -e "Using $GCOV"

 COVERAGE_DIR="$PWD/COVERAGE_REPORT"
 mkdir -p $COVERAGE_DIR

 # Find all gcno files to generate the coverage report

+PYTHON=${1:-`which python`}
+echo -e "Using $PYTHON"
 GCNO_FILES=`find $ROOT -name "*.gcno"`
 $GCOV --preserve-paths --relative-only --no-output $GCNO_FILES 2>/dev/null |
  # Parse the raw gcov report to more human readable form.
-  python $ROOT/coverage/parse_gcov_output.py |
+  $PYTHON $ROOT/coverage/parse_gcov_output.py |
  # Write the output to both stdout and report file.
  tee $COVERAGE_DIR/coverage_report_all.txt &&
 echo -e "Generated coverage report for all files: $COVERAGE_DIR/coverage_report_all.txt\n"
@@ -41,7 +44,7 @@ RECENT_REPORT=$COVERAGE_DIR/coverage_report_recent.txt

 echo -e "Recently updated files: $LATEST_FILES\n" > $RECENT_REPORT
 $GCOV --preserve-paths --relative-only --no-output $GCNO_FILES 2>/dev/null |
-  python $ROOT/coverage/parse_gcov_output.py -interested-files $LATEST_FILES |
+  $PYTHON $ROOT/coverage/parse_gcov_output.py -interested-files $LATEST_FILES |
  tee -a $RECENT_REPORT &&
 echo -e "Generated coverage report for recently updated files: $RECENT_REPORT\n"

@@ -1,10 +1,12 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python
 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+
+from __future__ import print_function
+
+import optparse
 import re
 import sys

-from optparse import OptionParser
-
 # the gcov report follows certain pattern. Each file will have two lines
 # of report, from which we can extract the file name, total lines and coverage
 # percentage.
@@ -48,7 +50,7 @@ def parse_gcov_report(gcov_input):
 def get_option_parser():
    usage = "Parse the gcov output and generate more human-readable code " +\
            "coverage report."
-    parser = OptionParser(usage)
+    parser = optparse.OptionParser(usage)

    parser.add_option(
        "--interested-files", "-i",
@@ -73,8 +75,8 @@ def display_file_coverage(per_file_coverage, total_coverage):
    header_template = \
        "%" + str(max_file_name_length) + "s\t%s\t%s"
    separator = "-" * (max_file_name_length + 10 + 20)
-    print header_template % ("Filename", "Coverage", "Lines")  # noqa: E999 T25377293 Grandfathered in
-    print separator
+    print(header_template % ("Filename", "Coverage", "Lines"))  # noqa: E999 T25377293 Grandfathered in
+    print(separator)

    # -- Print body
    # template for printing coverage report for each file.
@@ -82,12 +84,12 @@ def display_file_coverage(per_file_coverage, total_coverage):

    for fname, coverage_info in per_file_coverage.items():
        coverage, lines = coverage_info
-        print record_template % (fname, coverage, lines)
+        print(record_template % (fname, coverage, lines))

    # -- Print footer
    if total_coverage:
-        print separator
-        print record_template % ("Total", total_coverage[0], total_coverage[1])
+        print(separator)
+        print(record_template % ("Total", total_coverage[0], total_coverage[1]))

 def report_coverage():
    parser = get_option_parser()
@@ -111,7 +113,7 @@ def report_coverage():
        total_coverage = None

    if not len(per_file_coverage):
-        print >> sys.stderr, "Cannot find coverage info for the given files."
+        print("Cannot find coverage info for the given files.", file=sys.stderr)
        return
    display_file_coverage(per_file_coverage, total_coverage)

@@ -56,8 +56,9 @@ Status ArenaWrappedDBIter::Refresh() {
  // TODO(yiwu): For last_seq_same_as_publish_seq_==false, this is not the
  // correct behavior. Will be corrected automatically when we take a snapshot
  // here for the case of WritePreparedTxnDB.
-  SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
  uint64_t cur_sv_number = cfd_->GetSuperVersionNumber();
+  TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:1");
+  TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:2");
  if (sv_number_ != cur_sv_number) {
    Env* env = db_iter_->env();
    db_iter_->~DBIter();
@@ -65,6 +66,7 @@ Status ArenaWrappedDBIter::Refresh() {
    new (&arena_) Arena();

    SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_);
+    SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
    if (read_callback_) {
      read_callback_->Refresh(latest_seq);
    }
@@ -75,10 +77,10 @@ Status ArenaWrappedDBIter::Refresh() {

    InternalIterator* internal_iter = db_impl_->NewInternalIterator(
        read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator(),
-        latest_seq);
+        latest_seq, /* allow_unprepared_value */ true);
    SetIterUnderDBIter(internal_iter);
  } else {
-    db_iter_->set_sequence(latest_seq);
+    db_iter_->set_sequence(db_impl_->GetLatestSequenceNumber());
    db_iter_->set_valid(false);
  }
  return Status::OK();
@@ -0,0 +1,55 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_file_meta.h"
+
+#include <ostream>
+#include <sstream>
+
+namespace ROCKSDB_NAMESPACE {
+
+std::string SharedBlobFileMetaData::DebugString() const {
+  std::ostringstream oss;
+  oss << (*this);
+
+  return oss.str();
+}
+
+std::ostream& operator<<(std::ostream& os,
+                         const SharedBlobFileMetaData& shared_meta) {
+  os << "blob_file_number: " << shared_meta.GetBlobFileNumber()
+     << " total_blob_count: " << shared_meta.GetTotalBlobCount()
+     << " total_blob_bytes: " << shared_meta.GetTotalBlobBytes()
+     << " checksum_method: " << shared_meta.GetChecksumMethod()
+     << " checksum_value: " << shared_meta.GetChecksumValue();
+
+  return os;
+}
+
+std::string BlobFileMetaData::DebugString() const {
+  std::ostringstream oss;
+  oss << (*this);
+
+  return oss.str();
+}
+
+std::ostream& operator<<(std::ostream& os, const BlobFileMetaData& meta) {
+  const auto& shared_meta = meta.GetSharedMeta();
+  assert(shared_meta);
+  os << (*shared_meta);
+
+  os << " linked_ssts: {";
+  for (uint64_t file_number : meta.GetLinkedSsts()) {
+    os << ' ' << file_number;
+  }
+  os << " }";
+
+  os << " garbage_blob_count: " << meta.GetGarbageBlobCount()
+     << " garbage_blob_bytes: " << meta.GetGarbageBlobBytes();
+
+  return os;
+}
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -0,0 +1,164 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <cassert>
+#include <iosfwd>
+#include <memory>
+#include <string>
+#include <unordered_set>
+
+#include "rocksdb/rocksdb_namespace.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// SharedBlobFileMetaData represents the immutable part of blob files' metadata,
+// like the blob file number, total number and size of blobs, or checksum
+// method and value. There is supposed to be one object of this class per blob
+// file (shared across all versions that include the blob file in question);
+// hence, the type is neither copyable nor movable. A blob file can be marked
+// obsolete when the corresponding SharedBlobFileMetaData object is destroyed.
+
+class SharedBlobFileMetaData {
+ public:
+  static std::shared_ptr<SharedBlobFileMetaData> Create(
+      uint64_t blob_file_number, uint64_t total_blob_count,
+      uint64_t total_blob_bytes, std::string checksum_method,
+      std::string checksum_value) {
+    return std::shared_ptr<SharedBlobFileMetaData>(new SharedBlobFileMetaData(
+        blob_file_number, total_blob_count, total_blob_bytes,
+        std::move(checksum_method), std::move(checksum_value)));
+  }
+
+  template <typename Deleter>
+  static std::shared_ptr<SharedBlobFileMetaData> Create(
+      uint64_t blob_file_number, uint64_t total_blob_count,
+      uint64_t total_blob_bytes, std::string checksum_method,
+      std::string checksum_value, Deleter deleter) {
+    return std::shared_ptr<SharedBlobFileMetaData>(
+        new SharedBlobFileMetaData(blob_file_number, total_blob_count,
+                                   total_blob_bytes, std::move(checksum_method),
+                                   std::move(checksum_value)),
+        deleter);
+  }
+
+  SharedBlobFileMetaData(const SharedBlobFileMetaData&) = delete;
+  SharedBlobFileMetaData& operator=(const SharedBlobFileMetaData&) = delete;
+
+  SharedBlobFileMetaData(SharedBlobFileMetaData&&) = delete;
+  SharedBlobFileMetaData& operator=(SharedBlobFileMetaData&&) = delete;
+
+  uint64_t GetBlobFileNumber() const { return blob_file_number_; }
+  uint64_t GetTotalBlobCount() const { return total_blob_count_; }
+  uint64_t GetTotalBlobBytes() const { return total_blob_bytes_; }
+  const std::string& GetChecksumMethod() const { return checksum_method_; }
+  const std::string& GetChecksumValue() const { return checksum_value_; }
+
+  std::string DebugString() const;
+
+ private:
+  SharedBlobFileMetaData(uint64_t blob_file_number, uint64_t total_blob_count,
+                         uint64_t total_blob_bytes, std::string checksum_method,
+                         std::string checksum_value)
+      : blob_file_number_(blob_file_number),
+        total_blob_count_(total_blob_count),
+        total_blob_bytes_(total_blob_bytes),
+        checksum_method_(std::move(checksum_method)),
+        checksum_value_(std::move(checksum_value)) {
+    assert(checksum_method_.empty() == checksum_value_.empty());
+  }
+
+  uint64_t blob_file_number_;
+  uint64_t total_blob_count_;
+  uint64_t total_blob_bytes_;
+  std::string checksum_method_;
+  std::string checksum_value_;
+};
+
+std::ostream& operator<<(std::ostream& os,
+                         const SharedBlobFileMetaData& shared_meta);
+
+// BlobFileMetaData contains the part of the metadata for blob files that can
+// vary across versions, like the amount of garbage in the blob file. In
+// addition, BlobFileMetaData objects point to and share the ownership of the
+// SharedBlobFileMetaData object for the corresponding blob file. Similarly to
+// SharedBlobFileMetaData, BlobFileMetaData are not copyable or movable. They
+// are meant to be jointly owned by the versions in which the blob file has the
+// same (immutable *and* mutable) state.
+
+class BlobFileMetaData {
+ public:
+  using LinkedSsts = std::unordered_set<uint64_t>;
+
+  static std::shared_ptr<BlobFileMetaData> Create(
+      std::shared_ptr<SharedBlobFileMetaData> shared_meta,
+      LinkedSsts linked_ssts, uint64_t garbage_blob_count,
+      uint64_t garbage_blob_bytes) {
+    return std::shared_ptr<BlobFileMetaData>(
+        new BlobFileMetaData(std::move(shared_meta), std::move(linked_ssts),
+                             garbage_blob_count, garbage_blob_bytes));
+  }
+
+  BlobFileMetaData(const BlobFileMetaData&) = delete;
+  BlobFileMetaData& operator=(const BlobFileMetaData&) = delete;
+
+  BlobFileMetaData(BlobFileMetaData&&) = delete;
+  BlobFileMetaData& operator=(BlobFileMetaData&&) = delete;
+
+  const std::shared_ptr<SharedBlobFileMetaData>& GetSharedMeta() const {
+    return shared_meta_;
+  }
+
+  uint64_t GetBlobFileNumber() const {
+    assert(shared_meta_);
+    return shared_meta_->GetBlobFileNumber();
+  }
+  uint64_t GetTotalBlobCount() const {
+    assert(shared_meta_);
+    return shared_meta_->GetTotalBlobCount();
+  }
+  uint64_t GetTotalBlobBytes() const {
+    assert(shared_meta_);
+    return shared_meta_->GetTotalBlobBytes();
+  }
+  const std::string& GetChecksumMethod() const {
+    assert(shared_meta_);
+    return shared_meta_->GetChecksumMethod();
+  }
+  const std::string& GetChecksumValue() const {
+    assert(shared_meta_);
+    return shared_meta_->GetChecksumValue();
+  }
+
+  const LinkedSsts& GetLinkedSsts() const { return linked_ssts_; }
+
+  uint64_t GetGarbageBlobCount() const { return garbage_blob_count_; }
+  uint64_t GetGarbageBlobBytes() const { return garbage_blob_bytes_; }
+
+  std::string DebugString() const;
+
+ private:
+  BlobFileMetaData(std::shared_ptr<SharedBlobFileMetaData> shared_meta,
+                   LinkedSsts linked_ssts, uint64_t garbage_blob_count,
+                   uint64_t garbage_blob_bytes)
+      : shared_meta_(std::move(shared_meta)),
+        linked_ssts_(std::move(linked_ssts)),
+        garbage_blob_count_(garbage_blob_count),
+        garbage_blob_bytes_(garbage_blob_bytes) {
+    assert(shared_meta_);
+    assert(garbage_blob_count_ <= shared_meta_->GetTotalBlobCount());
+    assert(garbage_blob_bytes_ <= shared_meta_->GetTotalBlobBytes());
+  }
+
+  std::shared_ptr<SharedBlobFileMetaData> shared_meta_;
+  LinkedSsts linked_ssts_;
+  uint64_t garbage_blob_count_;
+  uint64_t garbage_blob_bytes_;
+};
+
+std::ostream& operator<<(std::ostream& os, const BlobFileMetaData& meta);
+
+}  // namespace ROCKSDB_NAMESPACE
@@ -5,7 +5,7 @@
 //
 #ifndef ROCKSDB_LITE

-#include "utilities/blob_db/blob_log_format.h"
+#include "db/blob/blob_log_format.h"

 #include "util/coding.h"
 #include "util/crc32c.h"
@@ -9,7 +9,6 @@

 #ifndef ROCKSDB_LITE

-#include <limits>
 #include <memory>
 #include <utility>

@@ -23,7 +22,6 @@ namespace blob_db {

 constexpr uint32_t kMagicNumber = 2395959;  // 0x00248f37
 constexpr uint32_t kVersion1 = 1;
-constexpr uint64_t kNoExpiration = std::numeric_limits<uint64_t>::max();

 using ExpirationRange = std::pair<uint64_t, uint64_t>;

@@ -5,7 +5,7 @@
 //
 #ifndef ROCKSDB_LITE

-#include "utilities/blob_db/blob_log_reader.h"
+#include "db/blob/blob_log_reader.h"

 #include <algorithm>

@@ -26,8 +26,8 @@ Reader::Reader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,

 Status Reader::ReadSlice(uint64_t size, Slice* slice, char* buf) {
  StopWatch read_sw(env_, statistics_, BLOB_DB_BLOB_FILE_READ_MICROS);
-  Status s =
-      file_->Read(next_byte_, static_cast<size_t>(size), slice, buf, nullptr);
+  Status s = file_->Read(IOOptions(), next_byte_, static_cast<size_t>(size),
+                         slice, buf, nullptr);
  next_byte_ += size;
  if (!s.ok()) {
    return s;
@@ -10,12 +10,12 @@
 #include <memory>
 #include <string>

+#include "db/blob/blob_log_format.h"
 #include "file/random_access_file_reader.h"
 #include "rocksdb/env.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/statistics.h"
 #include "rocksdb/status.h"
-#include "utilities/blob_db/blob_log_format.h"

 namespace ROCKSDB_NAMESPACE {

@@ -4,17 +4,17 @@
 //  (found in the LICENSE.Apache file in the root directory).
 #ifndef ROCKSDB_LITE

-#include "utilities/blob_db/blob_log_writer.h"
+#include "db/blob/blob_log_writer.h"

 #include <cstdint>
 #include <string>

+#include "db/blob/blob_log_format.h"
 #include "file/writable_file_writer.h"
 #include "monitoring/statistics.h"
 #include "rocksdb/env.h"
 #include "util/coding.h"
 #include "util/stop_watch.h"
-#include "utilities/blob_db/blob_log_format.h"

 namespace ROCKSDB_NAMESPACE {
 namespace blob_db {
@@ -10,12 +10,12 @@
 #include <memory>
 #include <string>

+#include "db/blob/blob_log_format.h"
 #include "rocksdb/env.h"
 #include "rocksdb/slice.h"
 #include "rocksdb/statistics.h"
 #include "rocksdb/status.h"
 #include "rocksdb/types.h"
-#include "utilities/blob_db/blob_log_format.h"

 namespace ROCKSDB_NAMESPACE {

@@ -81,10 +81,11 @@ Status BuildTable(
    SnapshotChecker* snapshot_checker, const CompressionType compression,
    uint64_t sample_for_compression, const CompressionOptions& compression_opts,
    bool paranoid_file_checks, InternalStats* internal_stats,
-    TableFileCreationReason reason, EventLogger* event_logger, int job_id,
-    const Env::IOPriority io_priority, TableProperties* table_properties,
-    int level, const uint64_t creation_time, const uint64_t oldest_key_time,
-    Env::WriteLifeTimeHint write_hint, const uint64_t file_creation_time) {
+    TableFileCreationReason reason, IOStatus* io_status,
+    EventLogger* event_logger, int job_id, const Env::IOPriority io_priority,
+    TableProperties* table_properties, int level, const uint64_t creation_time,
+    const uint64_t oldest_key_time, Env::WriteLifeTimeHint write_hint,
+    const uint64_t file_creation_time) {
  assert((column_family_id ==
          TablePropertiesCollectorFactory::Context::kUnknownColumnFamily) ==
         column_family_name.empty());
@@ -133,7 +134,7 @@ Status BuildTable(

      file_writer.reset(new WritableFileWriter(
          std::move(file), fname, file_options, env, ioptions.statistics,
-          ioptions.listeners, ioptions.sst_file_checksum_func));
+          ioptions.listeners, ioptions.file_checksum_gen_factory));

      builder = NewTableBuilder(
          ioptions, mutable_cf_options, internal_comparator,
@@ -182,14 +183,15 @@ Status BuildTable(
    }

    // Finish and check for builder errors
-    tp = builder->GetTableProperties();
-    bool empty = builder->NumEntries() == 0 && tp.num_range_deletions == 0;
+    bool empty = builder->IsEmpty();
    s = c_iter.status();
+    TEST_SYNC_POINT("BuildTable:BeforeFinishBuildTable");
    if (!s.ok() || empty) {
      builder->Abandon();
    } else {
      s = builder->Finish();
    }
+    *io_status = builder->io_status();

    if (s.ok() && !empty) {
      uint64_t file_size = builder->FileSize();
@@ -200,20 +202,28 @@ Status BuildTable(
      if (table_properties) {
        *table_properties = tp;
      }
-      // Add the checksum information to file metadata.
-      meta->file_checksum = builder->GetFileChecksum();
-      meta->file_checksum_func_name = builder->GetFileChecksumFuncName();
    }
    delete builder;

    // Finish and check for file errors
    if (s.ok() && !empty) {
      StopWatch sw(env, ioptions.statistics, TABLE_SYNC_MICROS);
-      s = file_writer->Sync(ioptions.use_fsync);
+      *io_status = file_writer->Sync(ioptions.use_fsync);
    }
-    if (s.ok() && !empty) {
-      s = file_writer->Close();
+    if (io_status->ok() && !empty) {
+      *io_status = file_writer->Close();
    }
+    if (io_status->ok() && !empty) {
+      // Add the checksum information to file metadata.
+      meta->file_checksum = file_writer->GetFileChecksum();
+      meta->file_checksum_func_name = file_writer->GetFileChecksumFuncName();
+    }
+
+    if (!io_status->ok()) {
+      s = *io_status;
+    }
+
+    // TODO Also check the IO status when create the Iterator.

    if (s.ok() && !empty) {
      // Verify that the table is usable
@@ -229,8 +239,11 @@ Status BuildTable(
          (internal_stats == nullptr) ? nullptr
                                      : internal_stats->GetFileReadHist(0),
          TableReaderCaller::kFlush, /*arena=*/nullptr,
-          /*skip_filter=*/false, level, /*smallest_compaction_key=*/nullptr,
-          /*largest_compaction_key*/ nullptr));
+          /*skip_filter=*/false, level,
+          MaxFileSizeForL0MetaPin(mutable_cf_options),
+          /*smallest_compaction_key=*/nullptr,
+          /*largest_compaction_key*/ nullptr,
+          /*allow_unprepared_value*/ false));
      s = it->status();
      if (s.ok() && paranoid_file_checks) {
        for (it->SeekToFirst(); it->Valid(); it->Next()) {
@@ -78,7 +78,7 @@ extern Status BuildTable(
    const uint64_t sample_for_compression,
    const CompressionOptions& compression_opts, bool paranoid_file_checks,
    InternalStats* internal_stats, TableFileCreationReason reason,
-    EventLogger* event_logger = nullptr, int job_id = 0,
+    IOStatus* io_status, EventLogger* event_logger = nullptr, int job_id = 0,
    const Env::IOPriority io_priority = Env::IO_HIGH,
    TableProperties* table_properties = nullptr, int level = -1,
    const uint64_t creation_time = 0, const uint64_t oldest_key_time = 0,
@@ -1466,6 +1466,11 @@ void rocksdb_writebatch_delete(
  b->rep.Delete(Slice(key, klen));
 }

+void rocksdb_writebatch_singledelete(rocksdb_writebatch_t* b, const char* key,
+                                     size_t klen) {
+  b->rep.SingleDelete(Slice(key, klen));
+}
+
 void rocksdb_writebatch_delete_cf(
    rocksdb_writebatch_t* b,
    rocksdb_column_family_handle_t* column_family,
@@ -1473,6 +1478,12 @@ void rocksdb_writebatch_delete_cf(
  b->rep.Delete(column_family->rep, Slice(key, klen));
 }

+void rocksdb_writebatch_singledelete_cf(
+    rocksdb_writebatch_t* b, rocksdb_column_family_handle_t* column_family,
+    const char* key, size_t klen) {
+  b->rep.SingleDelete(column_family->rep, Slice(key, klen));
+}
+
 void rocksdb_writebatch_deletev(
    rocksdb_writebatch_t* b,
    int num_keys, const char* const* keys_list,
@@ -1723,6 +1734,11 @@ void rocksdb_writebatch_wi_delete(
  b->rep->Delete(Slice(key, klen));
 }

+void rocksdb_writebatch_wi_singledelete(rocksdb_writebatch_wi_t* b,
+                                        const char* key, size_t klen) {
+  b->rep->SingleDelete(Slice(key, klen));
+}
+
 void rocksdb_writebatch_wi_delete_cf(
    rocksdb_writebatch_wi_t* b,
    rocksdb_column_family_handle_t* column_family,
@@ -1730,6 +1746,12 @@ void rocksdb_writebatch_wi_delete_cf(
  b->rep->Delete(column_family->rep, Slice(key, klen));
 }

+void rocksdb_writebatch_wi_singledelete_cf(
+    rocksdb_writebatch_wi_t* b, rocksdb_column_family_handle_t* column_family,
+    const char* key, size_t klen) {
+  b->rep->SingleDelete(column_family->rep, Slice(key, klen));
+}
+
 void rocksdb_writebatch_wi_deletev(
    rocksdb_writebatch_wi_t* b,
    int num_keys, const char* const* keys_list,
@@ -2154,6 +2176,10 @@ void rocksdb_options_destroy(rocksdb_options_t* options) {
  delete options;
 }

+rocksdb_options_t* rocksdb_options_create_copy(rocksdb_options_t* options) {
+  return new rocksdb_options_t(*options);
+}
+
 void rocksdb_options_increase_parallelism(
    rocksdb_options_t* opt, int total_threads) {
  opt->rep.IncreaseParallelism(total_threads);
@@ -2179,6 +2205,10 @@ void rocksdb_options_set_allow_ingest_behind(
  opt->rep.allow_ingest_behind = v;
 }

+unsigned char rocksdb_options_get_allow_ingest_behind(rocksdb_options_t* opt) {
+  return opt->rep.allow_ingest_behind;
+}
+
 void rocksdb_options_set_compaction_filter(
    rocksdb_options_t* opt,
    rocksdb_compactionfilter_t* filter) {
@@ -2196,6 +2226,10 @@ void rocksdb_options_compaction_readahead_size(
  opt->rep.compaction_readahead_size = s;
 }

+size_t rocksdb_options_get_compaction_readahead_size(rocksdb_options_t* opt) {
+  return opt->rep.compaction_readahead_size;
+}
+
 void rocksdb_options_set_comparator(
    rocksdb_options_t* opt,
    rocksdb_comparator_t* cmp) {
@@ -2208,27 +2242,43 @@ void rocksdb_options_set_merge_operator(
  opt->rep.merge_operator = std::shared_ptr<MergeOperator>(merge_operator);
 }

-
 void rocksdb_options_set_create_if_missing(
    rocksdb_options_t* opt, unsigned char v) {
  opt->rep.create_if_missing = v;
 }

+unsigned char rocksdb_options_get_create_if_missing(rocksdb_options_t* opt) {
+  return opt->rep.create_if_missing;
+}
+
 void rocksdb_options_set_create_missing_column_families(
    rocksdb_options_t* opt, unsigned char v) {
  opt->rep.create_missing_column_families = v;
 }

+unsigned char rocksdb_options_get_create_missing_column_families(
+    rocksdb_options_t* opt) {
+  return opt->rep.create_missing_column_families;
+}
+
 void rocksdb_options_set_error_if_exists(
    rocksdb_options_t* opt, unsigned char v) {
  opt->rep.error_if_exists = v;
 }

+unsigned char rocksdb_options_get_error_if_exists(rocksdb_options_t* opt) {
+  return opt->rep.error_if_exists;
+}
+
 void rocksdb_options_set_paranoid_checks(
    rocksdb_options_t* opt, unsigned char v) {
  opt->rep.paranoid_checks = v;
 }

+unsigned char rocksdb_options_get_paranoid_checks(rocksdb_options_t* opt) {
+  return opt->rep.paranoid_checks;
+}
+
 void rocksdb_options_set_db_paths(rocksdb_options_t* opt,
                                  const rocksdb_dbpath_t** dbpath_values,
                                  size_t num_paths) {
@@ -2254,52 +2304,98 @@ void rocksdb_options_set_info_log_level(
  opt->rep.info_log_level = static_cast<InfoLogLevel>(v);
 }

+int rocksdb_options_get_info_log_level(rocksdb_options_t* opt) {
+  return static_cast<int>(opt->rep.info_log_level);
+}
+
 void rocksdb_options_set_db_write_buffer_size(rocksdb_options_t* opt,
                                              size_t s) {
  opt->rep.db_write_buffer_size = s;
 }

+size_t rocksdb_options_get_db_write_buffer_size(rocksdb_options_t* opt) {
+  return opt->rep.db_write_buffer_size;
+}
+
 void rocksdb_options_set_write_buffer_size(rocksdb_options_t* opt, size_t s) {
  opt->rep.write_buffer_size = s;
 }

+size_t rocksdb_options_get_write_buffer_size(rocksdb_options_t* opt) {
+  return opt->rep.write_buffer_size;
+}
+
 void rocksdb_options_set_max_open_files(rocksdb_options_t* opt, int n) {
  opt->rep.max_open_files = n;
 }

+int rocksdb_options_get_max_open_files(rocksdb_options_t* opt) {
+  return opt->rep.max_open_files;
+}
+
 void rocksdb_options_set_max_file_opening_threads(rocksdb_options_t* opt, int n) {
  opt->rep.max_file_opening_threads = n;
 }

+int rocksdb_options_get_max_file_opening_threads(rocksdb_options_t* opt) {
+  return opt->rep.max_file_opening_threads;
+}
+
 void rocksdb_options_set_max_total_wal_size(rocksdb_options_t* opt, uint64_t n) {
  opt->rep.max_total_wal_size = n;
 }

+uint64_t rocksdb_options_get_max_total_wal_size(rocksdb_options_t* opt) {
+  return opt->rep.max_total_wal_size;
+}
+
 void rocksdb_options_set_target_file_size_base(
    rocksdb_options_t* opt, uint64_t n) {
  opt->rep.target_file_size_base = n;
 }

+uint64_t rocksdb_options_get_target_file_size_base(rocksdb_options_t* opt) {
+  return opt->rep.target_file_size_base;
+}
+
 void rocksdb_options_set_target_file_size_multiplier(
    rocksdb_options_t* opt, int n) {
  opt->rep.target_file_size_multiplier = n;
 }

+int rocksdb_options_get_target_file_size_multiplier(rocksdb_options_t* opt) {
+  return opt->rep.target_file_size_multiplier;
+}
+
 void rocksdb_options_set_max_bytes_for_level_base(
    rocksdb_options_t* opt, uint64_t n) {
  opt->rep.max_bytes_for_level_base = n;
 }

+uint64_t rocksdb_options_get_max_bytes_for_level_base(rocksdb_options_t* opt) {
+  return opt->rep.max_bytes_for_level_base;
+}
+
 void rocksdb_options_set_level_compaction_dynamic_level_bytes(
    rocksdb_options_t* opt, unsigned char v) {
  opt->rep.level_compaction_dynamic_level_bytes = v;
 }

+unsigned char rocksdb_options_get_level_compaction_dynamic_level_bytes(
+    rocksdb_options_t* opt) {
+  return opt->rep.level_compaction_dynamic_level_bytes;
+}
+
 void rocksdb_options_set_max_bytes_for_level_multiplier(rocksdb_options_t* opt,
                                                        double n) {
  opt->rep.max_bytes_for_level_multiplier = n;
 }

+double rocksdb_options_get_max_bytes_for_level_multiplier(
+    rocksdb_options_t* opt) {
+  return opt->rep.max_bytes_for_level_multiplier;
+}
+
 void rocksdb_options_set_max_compaction_bytes(rocksdb_options_t* opt,
                                              uint64_t n) {
  opt->rep.max_compaction_bytes = n;
@@ -2322,30 +2418,57 @@ void rocksdb_options_set_skip_stats_update_on_db_open(rocksdb_options_t* opt,
  opt->rep.skip_stats_update_on_db_open = val;
 }

+unsigned char rocksdb_options_get_skip_stats_update_on_db_open(
+    rocksdb_options_t* opt) {
+  return opt->rep.skip_stats_update_on_db_open;
+}
+
 void rocksdb_options_set_skip_checking_sst_file_sizes_on_db_open(
    rocksdb_options_t* opt, unsigned char val) {
  opt->rep.skip_checking_sst_file_sizes_on_db_open = val;
 }

+unsigned char rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(
+    rocksdb_options_t* opt) {
+  return opt->rep.skip_checking_sst_file_sizes_on_db_open;
+}
+
 void rocksdb_options_set_num_levels(rocksdb_options_t* opt, int n) {
  opt->rep.num_levels = n;
 }

+int rocksdb_options_get_num_levels(rocksdb_options_t* opt) {
+  return opt->rep.num_levels;
+}
+
 void rocksdb_options_set_level0_file_num_compaction_trigger(
    rocksdb_options_t* opt, int n) {
  opt->rep.level0_file_num_compaction_trigger = n;
 }

+int rocksdb_options_get_level0_file_num_compaction_trigger(
+    rocksdb_options_t* opt) {
+  return opt->rep.level0_file_num_compaction_trigger;
+}
+
 void rocksdb_options_set_level0_slowdown_writes_trigger(
    rocksdb_options_t* opt, int n) {
  opt->rep.level0_slowdown_writes_trigger = n;
 }

+int rocksdb_options_get_level0_slowdown_writes_trigger(rocksdb_options_t* opt) {
+  return opt->rep.level0_slowdown_writes_trigger;
+}
+
 void rocksdb_options_set_level0_stop_writes_trigger(
    rocksdb_options_t* opt, int n) {
  opt->rep.level0_stop_writes_trigger = n;
 }

+int rocksdb_options_get_level0_stop_writes_trigger(rocksdb_options_t* opt) {
+  return opt->rep.level0_stop_writes_trigger;
+}
+
 void rocksdb_options_set_max_mem_compaction_level(rocksdb_options_t* /*opt*/,
                                                  int /*n*/) {}

@@ -2357,6 +2480,10 @@ void rocksdb_options_set_compression(rocksdb_options_t* opt, int t) {
  opt->rep.compression = static_cast<CompressionType>(t);
 }

+void rocksdb_options_set_bottommost_compression(rocksdb_options_t* opt, int t) {
+  opt->rep.bottommost_compression = static_cast<CompressionType>(t);
+}
+
 void rocksdb_options_set_compression_per_level(rocksdb_options_t* opt,
                                               int* level_values,
                                               size_t num_levels) {
@@ -2371,7 +2498,7 @@ void rocksdb_options_set_bottommost_compression_options(rocksdb_options_t* opt,
                                                        int w_bits, int level,
                                                        int strategy,
                                                        int max_dict_bytes,
-                                                        bool enabled) {
+                                                        unsigned char enabled) {
  opt->rep.bottommost_compression_opts.window_bits = w_bits;
  opt->rep.bottommost_compression_opts.level = level;
  opt->rep.bottommost_compression_opts.strategy = strategy;
@@ -2379,6 +2506,13 @@ void rocksdb_options_set_bottommost_compression_options(rocksdb_options_t* opt,
  opt->rep.bottommost_compression_opts.enabled = enabled;
 }

+void rocksdb_options_set_bottommost_compression_options_zstd_max_train_bytes(
+    rocksdb_options_t* opt, int zstd_max_train_bytes, unsigned char enabled) {
+  opt->rep.bottommost_compression_opts.zstd_max_train_bytes =
+      zstd_max_train_bytes;
+  opt->rep.bottommost_compression_opts.enabled = enabled;
+}
+
 void rocksdb_options_set_compression_options(rocksdb_options_t* opt, int w_bits,
                                             int level, int strategy,
                                             int max_dict_bytes) {
@@ -2388,6 +2522,11 @@ void rocksdb_options_set_compression_options(rocksdb_options_t* opt, int w_bits,
  opt->rep.compression_opts.max_dict_bytes = max_dict_bytes;
 }

+void rocksdb_options_set_compression_options_zstd_max_train_bytes(
+    rocksdb_options_t* opt, int zstd_max_train_bytes) {
+  opt->rep.compression_opts.zstd_max_train_bytes = zstd_max_train_bytes;
+}
+
 void rocksdb_options_set_prefix_extractor(
    rocksdb_options_t* opt, rocksdb_slicetransform_t* prefix_extractor) {
  opt->rep.prefix_extractor.reset(prefix_extractor);
@@ -2527,35 +2666,67 @@ void rocksdb_options_set_max_write_buffer_number(rocksdb_options_t* opt, int n)
  opt->rep.max_write_buffer_number = n;
 }

+int rocksdb_options_get_max_write_buffer_number(rocksdb_options_t* opt) {
+  return opt->rep.max_write_buffer_number;
+}
+
 void rocksdb_options_set_min_write_buffer_number_to_merge(rocksdb_options_t* opt, int n) {
  opt->rep.min_write_buffer_number_to_merge = n;
 }

+int rocksdb_options_get_min_write_buffer_number_to_merge(
+    rocksdb_options_t* opt) {
+  return opt->rep.min_write_buffer_number_to_merge;
+}
+
 void rocksdb_options_set_max_write_buffer_number_to_maintain(
    rocksdb_options_t* opt, int n) {
  opt->rep.max_write_buffer_number_to_maintain = n;
 }

+int rocksdb_options_get_max_write_buffer_number_to_maintain(
+    rocksdb_options_t* opt) {
+  return opt->rep.max_write_buffer_number_to_maintain;
+}
+
 void rocksdb_options_set_max_write_buffer_size_to_maintain(
    rocksdb_options_t* opt, int64_t n) {
  opt->rep.max_write_buffer_size_to_maintain = n;
 }

+int64_t rocksdb_options_get_max_write_buffer_size_to_maintain(
+    rocksdb_options_t* opt) {
+  return opt->rep.max_write_buffer_size_to_maintain;
+}
+
 void rocksdb_options_set_enable_pipelined_write(rocksdb_options_t* opt,
                                                unsigned char v) {
  opt->rep.enable_pipelined_write = v;
 }

+unsigned char rocksdb_options_get_enable_pipelined_write(
+    rocksdb_options_t* opt) {
+  return opt->rep.enable_pipelined_write;
+}
+
 void rocksdb_options_set_unordered_write(rocksdb_options_t* opt,
                                         unsigned char v) {
  opt->rep.unordered_write = v;
 }

+unsigned char rocksdb_options_get_unordered_write(rocksdb_options_t* opt) {
+  return opt->rep.unordered_write;
+}
+
 void rocksdb_options_set_max_subcompactions(rocksdb_options_t* opt,
                                            uint32_t n) {
  opt->rep.max_subcompactions = n;
 }

+uint32_t rocksdb_options_get_max_subcompactions(rocksdb_options_t* opt) {
+  return opt->rep.max_subcompactions;
+}
+
 void rocksdb_options_set_max_background_jobs(rocksdb_options_t* opt, int n) {
  opt->rep.max_background_jobs = n;
 }
@@ -4441,11 +4612,25 @@ uint64_t rocksdb_approximate_memory_usage_get_cache_total(
  return memory_usage->cache_total;
 }

+void rocksdb_options_set_dump_malloc_stats(rocksdb_options_t* opt,
+                                           unsigned char val) {
+  opt->rep.dump_malloc_stats = val;
+}
+
+void rocksdb_options_set_memtable_whole_key_filtering(rocksdb_options_t* opt,
+                                                      unsigned char val) {
+  opt->rep.memtable_whole_key_filtering = val;
+}
+
 // deletes container with memory usage estimates
 void rocksdb_approximate_memory_usage_destroy(rocksdb_memory_usage_t* usage) {
  delete usage;
 }

+void rocksdb_cancel_all_background_work(rocksdb_t* db, unsigned char wait) {
+  CancelAllBackgroundWork(db->rep, wait);
+}
+
 }  // end extern "C"

 #endif  // !ROCKSDB_LITE
@@ -1461,6 +1461,294 @@ int main(int argc, char** argv) {
    rocksdb_cuckoo_options_destroy(cuckoo_options);
  }

+  StartPhase("options");
+  {
+    rocksdb_options_t* o;
+    o = rocksdb_options_create();
+
+    // Set and check options.
+    rocksdb_options_set_allow_ingest_behind(o, 1);
+    CheckCondition(1 == rocksdb_options_get_allow_ingest_behind(o));
+
+    rocksdb_options_compaction_readahead_size(o, 10);
+    CheckCondition(10 == rocksdb_options_get_compaction_readahead_size(o));
+
+    rocksdb_options_set_create_if_missing(o, 1);
+    CheckCondition(1 == rocksdb_options_get_create_if_missing(o));
+
+    rocksdb_options_set_create_missing_column_families(o, 1);
+    CheckCondition(1 == rocksdb_options_get_create_missing_column_families(o));
+
+    rocksdb_options_set_error_if_exists(o, 1);
+    CheckCondition(1 == rocksdb_options_get_error_if_exists(o));
+
+    rocksdb_options_set_paranoid_checks(o, 1);
+    CheckCondition(1 == rocksdb_options_get_paranoid_checks(o));
+
+    rocksdb_options_set_info_log_level(o, 3);
+    CheckCondition(3 == rocksdb_options_get_info_log_level(o));
+
+    rocksdb_options_set_write_buffer_size(o, 100);
+    CheckCondition(100 == rocksdb_options_get_write_buffer_size(o));
+
+    rocksdb_options_set_db_write_buffer_size(o, 1000);
+    CheckCondition(1000 == rocksdb_options_get_db_write_buffer_size(o));
+
+    rocksdb_options_set_max_open_files(o, 21);
+    CheckCondition(21 == rocksdb_options_get_max_open_files(o));
+
+    rocksdb_options_set_max_file_opening_threads(o, 5);
+    CheckCondition(5 == rocksdb_options_get_max_file_opening_threads(o));
+
+    rocksdb_options_set_max_total_wal_size(o, 400);
+    CheckCondition(400 == rocksdb_options_get_max_total_wal_size(o));
+
+    rocksdb_options_set_num_levels(o, 7);
+    CheckCondition(7 == rocksdb_options_get_num_levels(o));
+
+    rocksdb_options_set_level0_file_num_compaction_trigger(o, 4);
+    CheckCondition(4 ==
+                   rocksdb_options_get_level0_file_num_compaction_trigger(o));
+
+    rocksdb_options_set_level0_slowdown_writes_trigger(o, 6);
+    CheckCondition(6 == rocksdb_options_get_level0_slowdown_writes_trigger(o));
+
+    rocksdb_options_set_level0_stop_writes_trigger(o, 8);
+    CheckCondition(8 == rocksdb_options_get_level0_stop_writes_trigger(o));
+
+    rocksdb_options_set_target_file_size_base(o, 256);
+    CheckCondition(256 == rocksdb_options_get_target_file_size_base(o));
+
+    rocksdb_options_set_target_file_size_multiplier(o, 3);
+    CheckCondition(3 == rocksdb_options_get_target_file_size_multiplier(o));
+
+    rocksdb_options_set_max_bytes_for_level_base(o, 1024);
+    CheckCondition(1024 == rocksdb_options_get_max_bytes_for_level_base(o));
+
+    rocksdb_options_set_level_compaction_dynamic_level_bytes(o, 1);
+    CheckCondition(1 ==
+                   rocksdb_options_get_level_compaction_dynamic_level_bytes(o));
+
+    rocksdb_options_set_max_bytes_for_level_multiplier(o, 2.0);
+    CheckCondition(2.0 ==
+                   rocksdb_options_get_max_bytes_for_level_multiplier(o));
+
+    rocksdb_options_set_skip_stats_update_on_db_open(o, 1);
+    CheckCondition(1 == rocksdb_options_get_skip_stats_update_on_db_open(o));
+
+    rocksdb_options_set_skip_checking_sst_file_sizes_on_db_open(o, 1);
+    CheckCondition(
+        1 == rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(o));
+
+    rocksdb_options_set_max_write_buffer_number(o, 97);
+    CheckCondition(97 == rocksdb_options_get_max_write_buffer_number(o));
+
+    rocksdb_options_set_min_write_buffer_number_to_merge(o, 23);
+    CheckCondition(23 ==
+                   rocksdb_options_get_min_write_buffer_number_to_merge(o));
+
+    rocksdb_options_set_max_write_buffer_number_to_maintain(o, 64);
+    CheckCondition(64 ==
+                   rocksdb_options_get_max_write_buffer_number_to_maintain(o));
+
+    rocksdb_options_set_max_write_buffer_size_to_maintain(o, 50000);
+    CheckCondition(50000 ==
+                   rocksdb_options_get_max_write_buffer_size_to_maintain(o));
+
+    rocksdb_options_set_enable_pipelined_write(o, 1);
+    CheckCondition(1 == rocksdb_options_get_enable_pipelined_write(o));
+
+    rocksdb_options_set_unordered_write(o, 1);
+    CheckCondition(1 == rocksdb_options_get_unordered_write(o));
+
+    rocksdb_options_set_max_subcompactions(o, 123456);
+    CheckCondition(123456 == rocksdb_options_get_max_subcompactions(o));
+
+    // Create a copy that should be equal to the original.
+    rocksdb_options_t* copy;
+    copy = rocksdb_options_create_copy(o);
+
+    CheckCondition(1 == rocksdb_options_get_allow_ingest_behind(copy));
+    CheckCondition(10 == rocksdb_options_get_compaction_readahead_size(copy));
+    CheckCondition(1 == rocksdb_options_get_create_if_missing(copy));
+    CheckCondition(1 ==
+                   rocksdb_options_get_create_missing_column_families(copy));
+    CheckCondition(1 == rocksdb_options_get_error_if_exists(copy));
+    CheckCondition(1 == rocksdb_options_get_paranoid_checks(copy));
+    CheckCondition(3 == rocksdb_options_get_info_log_level(copy));
+    CheckCondition(100 == rocksdb_options_get_write_buffer_size(copy));
+    CheckCondition(1000 == rocksdb_options_get_db_write_buffer_size(copy));
+    CheckCondition(21 == rocksdb_options_get_max_open_files(copy));
+    CheckCondition(5 == rocksdb_options_get_max_file_opening_threads(copy));
+    CheckCondition(400 == rocksdb_options_get_max_total_wal_size(copy));
+    CheckCondition(7 == rocksdb_options_get_num_levels(copy));
+    CheckCondition(
+        4 == rocksdb_options_get_level0_file_num_compaction_trigger(copy));
+    CheckCondition(6 ==
+                   rocksdb_options_get_level0_slowdown_writes_trigger(copy));
+    CheckCondition(8 == rocksdb_options_get_level0_stop_writes_trigger(copy));
+    CheckCondition(256 == rocksdb_options_get_target_file_size_base(copy));
+    CheckCondition(3 == rocksdb_options_get_target_file_size_multiplier(copy));
+    CheckCondition(1024 == rocksdb_options_get_max_bytes_for_level_base(copy));
+    CheckCondition(
+        1 == rocksdb_options_get_level_compaction_dynamic_level_bytes(copy));
+    CheckCondition(2.0 ==
+                   rocksdb_options_get_max_bytes_for_level_multiplier(copy));
+    CheckCondition(1 == rocksdb_options_get_skip_stats_update_on_db_open(copy));
+    CheckCondition(
+        1 == rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(copy));
+    CheckCondition(97 == rocksdb_options_get_max_write_buffer_number(copy));
+    CheckCondition(23 ==
+                   rocksdb_options_get_min_write_buffer_number_to_merge(copy));
+    CheckCondition(
+        64 == rocksdb_options_get_max_write_buffer_number_to_maintain(copy));
+    CheckCondition(50000 ==
+                   rocksdb_options_get_max_write_buffer_size_to_maintain(copy));
+    CheckCondition(1 == rocksdb_options_get_enable_pipelined_write(copy));
+    CheckCondition(1 == rocksdb_options_get_unordered_write(copy));
+    CheckCondition(123456 == rocksdb_options_get_max_subcompactions(copy));
+
+    // Copies should be independent.
+    rocksdb_options_set_allow_ingest_behind(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_allow_ingest_behind(copy));
+    CheckCondition(1 == rocksdb_options_get_allow_ingest_behind(o));
+
+    rocksdb_options_compaction_readahead_size(copy, 20);
+    CheckCondition(20 == rocksdb_options_get_compaction_readahead_size(copy));
+    CheckCondition(10 == rocksdb_options_get_compaction_readahead_size(o));
+
+    rocksdb_options_set_create_if_missing(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_create_if_missing(copy));
+    CheckCondition(1 == rocksdb_options_get_create_if_missing(o));
+
+    rocksdb_options_set_create_missing_column_families(copy, 0);
+    CheckCondition(0 ==
+                   rocksdb_options_get_create_missing_column_families(copy));
+    CheckCondition(1 == rocksdb_options_get_create_missing_column_families(o));
+
+    rocksdb_options_set_error_if_exists(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_error_if_exists(copy));
+    CheckCondition(1 == rocksdb_options_get_error_if_exists(o));
+
+    rocksdb_options_set_paranoid_checks(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_paranoid_checks(copy));
+    CheckCondition(1 == rocksdb_options_get_paranoid_checks(o));
+
+    rocksdb_options_set_info_log_level(copy, 2);
+    CheckCondition(2 == rocksdb_options_get_info_log_level(copy));
+    CheckCondition(3 == rocksdb_options_get_info_log_level(o));
+
+    rocksdb_options_set_write_buffer_size(copy, 200);
+    CheckCondition(200 == rocksdb_options_get_write_buffer_size(copy));
+    CheckCondition(100 == rocksdb_options_get_write_buffer_size(o));
+
+    rocksdb_options_set_db_write_buffer_size(copy, 2000);
+    CheckCondition(2000 == rocksdb_options_get_db_write_buffer_size(copy));
+    CheckCondition(1000 == rocksdb_options_get_db_write_buffer_size(o));
+
+    rocksdb_options_set_max_open_files(copy, 42);
+    CheckCondition(42 == rocksdb_options_get_max_open_files(copy));
+    CheckCondition(21 == rocksdb_options_get_max_open_files(o));
+
+    rocksdb_options_set_max_file_opening_threads(copy, 3);
+    CheckCondition(3 == rocksdb_options_get_max_file_opening_threads(copy));
+    CheckCondition(5 == rocksdb_options_get_max_file_opening_threads(o));
+
+    rocksdb_options_set_max_total_wal_size(copy, 4000);
+    CheckCondition(4000 == rocksdb_options_get_max_total_wal_size(copy));
+    CheckCondition(400 == rocksdb_options_get_max_total_wal_size(o));
+
+    rocksdb_options_set_num_levels(copy, 6);
+    CheckCondition(6 == rocksdb_options_get_num_levels(copy));
+    CheckCondition(7 == rocksdb_options_get_num_levels(o));
+
+    rocksdb_options_set_level0_file_num_compaction_trigger(copy, 14);
+    CheckCondition(
+        14 == rocksdb_options_get_level0_file_num_compaction_trigger(copy));
+    CheckCondition(4 ==
+                   rocksdb_options_get_level0_file_num_compaction_trigger(o));
+
+    rocksdb_options_set_level0_slowdown_writes_trigger(copy, 61);
+    CheckCondition(61 ==
+                   rocksdb_options_get_level0_slowdown_writes_trigger(copy));
+    CheckCondition(6 == rocksdb_options_get_level0_slowdown_writes_trigger(o));
+
+    rocksdb_options_set_level0_stop_writes_trigger(copy, 17);
+    CheckCondition(17 == rocksdb_options_get_level0_stop_writes_trigger(copy));
+    CheckCondition(8 == rocksdb_options_get_level0_stop_writes_trigger(o));
+
+    rocksdb_options_set_target_file_size_base(copy, 128);
+    CheckCondition(128 == rocksdb_options_get_target_file_size_base(copy));
+    CheckCondition(256 == rocksdb_options_get_target_file_size_base(o));
+
+    rocksdb_options_set_target_file_size_multiplier(copy, 13);
+    CheckCondition(13 == rocksdb_options_get_target_file_size_multiplier(copy));
+    CheckCondition(3 == rocksdb_options_get_target_file_size_multiplier(o));
+
+    rocksdb_options_set_max_bytes_for_level_base(copy, 900);
+    CheckCondition(900 == rocksdb_options_get_max_bytes_for_level_base(copy));
+    CheckCondition(1024 == rocksdb_options_get_max_bytes_for_level_base(o));
+
+    rocksdb_options_set_level_compaction_dynamic_level_bytes(copy, 0);
+    CheckCondition(
+        0 == rocksdb_options_get_level_compaction_dynamic_level_bytes(copy));
+    CheckCondition(1 ==
+                   rocksdb_options_get_level_compaction_dynamic_level_bytes(o));
+
+    rocksdb_options_set_max_bytes_for_level_multiplier(copy, 8.0);
+    CheckCondition(8.0 ==
+                   rocksdb_options_get_max_bytes_for_level_multiplier(copy));
+    CheckCondition(2.0 ==
+                   rocksdb_options_get_max_bytes_for_level_multiplier(o));
+
+    rocksdb_options_set_skip_stats_update_on_db_open(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_skip_stats_update_on_db_open(copy));
+    CheckCondition(1 == rocksdb_options_get_skip_stats_update_on_db_open(o));
+
+    rocksdb_options_set_skip_checking_sst_file_sizes_on_db_open(copy, 0);
+    CheckCondition(
+        0 == rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(copy));
+    CheckCondition(
+        1 == rocksdb_options_get_skip_checking_sst_file_sizes_on_db_open(o));
+
+    rocksdb_options_set_max_write_buffer_number(copy, 2000);
+    CheckCondition(2000 == rocksdb_options_get_max_write_buffer_number(copy));
+    CheckCondition(97 == rocksdb_options_get_max_write_buffer_number(o));
+
+    rocksdb_options_set_min_write_buffer_number_to_merge(copy, 146);
+    CheckCondition(146 ==
+                   rocksdb_options_get_min_write_buffer_number_to_merge(copy));
+    CheckCondition(23 ==
+                   rocksdb_options_get_min_write_buffer_number_to_merge(o));
+
+    rocksdb_options_set_max_write_buffer_number_to_maintain(copy, 128);
+    CheckCondition(
+        128 == rocksdb_options_get_max_write_buffer_number_to_maintain(copy));
+    CheckCondition(64 ==
+                   rocksdb_options_get_max_write_buffer_number_to_maintain(o));
+
+    rocksdb_options_set_max_write_buffer_size_to_maintain(copy, 9000);
+    CheckCondition(9000 ==
+                   rocksdb_options_get_max_write_buffer_size_to_maintain(copy));
+    CheckCondition(50000 ==
+                   rocksdb_options_get_max_write_buffer_size_to_maintain(o));
+
+    rocksdb_options_set_enable_pipelined_write(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_enable_pipelined_write(copy));
+    CheckCondition(1 == rocksdb_options_get_enable_pipelined_write(o));
+
+    rocksdb_options_set_unordered_write(copy, 0);
+    CheckCondition(0 == rocksdb_options_get_unordered_write(copy));
+    CheckCondition(1 == rocksdb_options_get_unordered_write(o));
+
+    rocksdb_options_set_max_subcompactions(copy, 90001);
+    CheckCondition(90001 == rocksdb_options_get_max_subcompactions(copy));
+    CheckCondition(123456 == rocksdb_options_get_max_subcompactions(o));
+
+    rocksdb_options_destroy(copy);
+    rocksdb_options_destroy(o);
+  }
+
  StartPhase("iterate_upper_bound");
  {
    // Create new empty database
@@ -1840,6 +2128,9 @@ int main(int argc, char** argv) {
    CheckNoError(err);
  }

+  StartPhase("cancel_all_background_work");
+  rocksdb_cancel_all_background_work(db, 1);
+
  StartPhase("cleanup");
  rocksdb_close(db);
  rocksdb_options_destroy(options);
@@ -1397,8 +1397,8 @@ ColumnFamilySet::ColumnFamilySet(const std::string& dbname,
                                 const ImmutableDBOptions* db_options,
                                 const FileOptions& file_options,
                                 Cache* table_cache,
-                                 WriteBufferManager* write_buffer_manager,
-                                 WriteController* write_controller,
+                                 WriteBufferManager* _write_buffer_manager,
+                                 WriteController* _write_controller,
                                 BlockCacheTracer* const block_cache_tracer)
    : max_column_family_(0),
      dummy_cfd_(new ColumnFamilyData(
@@ -1410,8 +1410,8 @@ ColumnFamilySet::ColumnFamilySet(const std::string& dbname,
      db_options_(db_options),
      file_options_(file_options),
      table_cache_(table_cache),
-      write_buffer_manager_(write_buffer_manager),
-      write_controller_(write_controller),
+      write_buffer_manager_(_write_buffer_manager),
+      write_controller_(_write_controller),
      block_cache_tracer_(block_cache_tracer) {
  // initialize linked list
  dummy_cfd_->prev_ = dummy_cfd_;
@@ -647,8 +647,8 @@ class ColumnFamilySet {
  ColumnFamilySet(const std::string& dbname,
                  const ImmutableDBOptions* db_options,
                  const FileOptions& file_options, Cache* table_cache,
-                  WriteBufferManager* write_buffer_manager,
-                  WriteController* write_controller,
+                  WriteBufferManager* _write_buffer_manager,
+                  WriteController* _write_controller,
                  BlockCacheTracer* const block_cache_tracer);
  ~ColumnFamilySet();

@@ -678,6 +678,10 @@ class ColumnFamilySet {

  Cache* get_table_cache() { return table_cache_; }

+  WriteBufferManager* write_buffer_manager() { return write_buffer_manager_; }
+
+  WriteController* write_controller() { return write_controller_; }
+
 private:
  friend class ColumnFamilyData;
  // helper function that gets called from cfd destructor
@@ -8,16 +8,16 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.

 #include <algorithm>
-#include <vector>
 #include <string>
 #include <thread>
+#include <vector>

 #include "db/db_impl/db_impl.h"
 #include "db/db_test_util.h"
-#include "memtable/hash_skiplist_rep.h"
 #include "options/options_parser.h"
 #include "port/port.h"
 #include "port/stack_trace.h"
+#include "rocksdb/convenience.h"
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
@@ -287,7 +287,9 @@ class ColumnFamilyTestBase : public testing::Test {
      // Verify the CF options of the returned CF handle.
      ColumnFamilyDescriptor desc;
      ASSERT_OK(handles_[cfi]->GetDescriptor(&desc));
-      RocksDBOptionsParser::VerifyCFOptions(desc.options, current_cf_opt);
+      RocksDBOptionsParser::VerifyCFOptions(ConfigOptions(), desc.options,
+                                            current_cf_opt);
+
 #endif  // !ROCKSDB_LITE
      cfi++;
    }
@@ -23,7 +23,7 @@ const uint64_t kRangeTombstoneSentinel =

 int sstableKeyCompare(const Comparator* user_cmp, const InternalKey& a,
                      const InternalKey& b) {
-  auto c = user_cmp->Compare(a.user_key(), b.user_key());
+  auto c = user_cmp->CompareWithoutTimestamp(a.user_key(), b.user_key());
  if (c != 0) {
    return c;
  }
@@ -246,6 +246,7 @@ void CompactionIterator::NextFromInput() {
    iter_stats_.num_input_records++;

    if (!ParseInternalKey(key_, &ikey_)) {
+      iter_stats_.num_input_corrupt_records++;
      // If `expect_valid_internal_key_` is false, return the corrupted key
      // and let the caller decide what to do with it.
      // TODO(noetzli): We should have a more elegant solution for this.
@@ -258,7 +259,6 @@ void CompactionIterator::NextFromInput() {
      has_current_user_key_ = false;
      current_user_key_sequence_ = kMaxSequenceNumber;
      current_user_key_snapshot_ = 0;
-      iter_stats_.num_input_corrupt_records++;
      valid_ = true;
      break;
    }
@@ -542,7 +542,7 @@ void CompactionJob::GenSubcompactionBoundaries() {
    // Greedily add ranges to the subcompaction until the sum of the ranges'
    // sizes becomes >= the expected mean size of a subcompaction
    sum = 0;
-    for (size_t i = 0; i < ranges.size() - 1; i++) {
+    for (size_t i = 0; i + 1 < ranges.size(); i++) {
      sum += ranges[i].size;
      if (subcompactions == 1) {
        // If there's only one left to schedule then it goes to the end so no
@@ -613,8 +613,13 @@ Status CompactionJob::Run() {
    }
  }

+  IOStatus io_s;
  if (status.ok() && output_directory_) {
-    status = output_directory_->Fsync(IOOptions(), nullptr);
+    io_s = output_directory_->Fsync(IOOptions(), nullptr);
+  }
+  if (!io_s.ok()) {
+    io_status_ = io_s;
+    status = io_s;
  }

  if (status.ok()) {
@@ -649,8 +654,11 @@ Status CompactionJob::Run() {
                compact_->compaction->output_level()),
            TableReaderCaller::kCompactionRefill, /*arena=*/nullptr,
            /*skip_filters=*/false, compact_->compaction->output_level(),
+            MaxFileSizeForL0MetaPin(
+                *compact_->compaction->mutable_cf_options()),
            /*smallest_compaction_key=*/nullptr,
-            /*largest_compaction_key=*/nullptr);
+            /*largest_compaction_key=*/nullptr,
+            /*allow_unprepared_value=*/false);
        auto s = iter->status();

        if (s.ok() && paranoid_file_checks_) {
@@ -716,6 +724,9 @@ Status CompactionJob::Install(const MutableCFOptions& mutable_cf_options) {
  if (status.ok()) {
    status = InstallCompactionResults(mutable_cf_options);
  }
+  if (!versions_->io_status().ok()) {
+    io_status_ = versions_->io_status();
+  }
  VersionStorageInfo::LevelSummaryStorage tmp;
  auto vstorage = cfd->current()->storage_info();
  const auto& stats = compaction_stats_;
@@ -884,9 +895,10 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
  sub_compact->c_iter.reset(new CompactionIterator(
      input.get(), cfd->user_comparator(), &merge, versions_->LastSequence(),
      &existing_snapshots_, earliest_write_conflict_snapshot_,
-      snapshot_checker_, env_, ShouldReportDetailedTime(env_, stats_), false,
-      &range_del_agg, sub_compact->compaction, compaction_filter,
-      shutting_down_, preserve_deletes_seqnum_, manual_compaction_paused_,
+      snapshot_checker_, env_, ShouldReportDetailedTime(env_, stats_),
+      /*expect_valid_internal_key=*/true, &range_del_agg,
+      sub_compact->compaction, compaction_filter, shutting_down_,
+      preserve_deletes_seqnum_, manual_compaction_paused_,
      db_options_.info_log));
  auto c_iter = sub_compact->c_iter.get();
  c_iter->SeekToFirst();
@@ -928,7 +940,8 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
    assert(sub_compact->builder != nullptr);
    assert(sub_compact->current_output() != nullptr);
    sub_compact->builder->Add(key, value);
-    sub_compact->current_output_file_size = sub_compact->builder->FileSize();
+    sub_compact->current_output_file_size =
+        sub_compact->builder->EstimatedFileSize();
    const ParsedInternalKey& ikey = c_iter->ikey();
    sub_compact->current_output()->meta.UpdateBoundaries(
        key, value, ikey.sequence, ikey.type);
@@ -1294,25 +1307,35 @@ Status CompactionJob::FinishCompactionOutputFile(
  } else {
    sub_compact->builder->Abandon();
  }
+  if (!sub_compact->builder->io_status().ok()) {
+    io_status_ = sub_compact->builder->io_status();
+    s = io_status_;
+  }
  const uint64_t current_bytes = sub_compact->builder->FileSize();
  if (s.ok()) {
-    // Add the checksum information to file metadata.
-    meta->file_checksum = sub_compact->builder->GetFileChecksum();
-    meta->file_checksum_func_name =
-        sub_compact->builder->GetFileChecksumFuncName();
-
    meta->fd.file_size = current_bytes;
  }
  sub_compact->current_output()->finished = true;
  sub_compact->total_bytes += current_bytes;

  // Finish and check for file errors
+  IOStatus io_s;
  if (s.ok()) {
    StopWatch sw(env_, stats_, COMPACTION_OUTFILE_SYNC_MICROS);
-    s = sub_compact->outfile->Sync(db_options_.use_fsync);
+    io_s = sub_compact->outfile->Sync(db_options_.use_fsync);
  }
-  if (s.ok()) {
-    s = sub_compact->outfile->Close();
+  if (io_s.ok()) {
+    io_s = sub_compact->outfile->Close();
+  }
+  if (io_s.ok()) {
+    // Add the checksum information to file metadata.
+    meta->file_checksum = sub_compact->outfile->GetFileChecksum();
+    meta->file_checksum_func_name =
+        sub_compact->outfile->GetFileChecksumFuncName();
+  }
+  if (!io_s.ok()) {
+    io_status_ = io_s;
+    s = io_s;
  }
  sub_compact->outfile.reset();

@@ -1514,7 +1537,7 @@ Status CompactionJob::OpenCompactionOutputFile(
  sub_compact->outfile.reset(
      new WritableFileWriter(std::move(writable_file), fname, file_options_,
                             env_, db_options_.statistics.get(), listeners,
-                             db_options_.sst_file_checksum_func.get()));
+                             db_options_.file_checksum_gen_factory.get()));

  // If the Column family flag is to only optimize filters for hits,
  // we can skip creating filters if this is the bottommost_level where
@@ -100,6 +100,9 @@ class CompactionJob {
  // Add compaction input/output to the current version
  Status Install(const MutableCFOptions& mutable_cf_options);

+  // Return the IO status
+  IOStatus io_status() const { return io_status_; }
+
 private:
  struct SubcompactionState;

@@ -193,6 +196,7 @@ class CompactionJob {
  std::vector<uint64_t> sizes_;
  Env::WriteLifeTimeHint write_hint_;
  Env::Priority thread_pri_;
+  IOStatus io_status_;
 };

 }  // namespace ROCKSDB_NAMESPACE
@@ -281,7 +281,7 @@ class CompactionJobTest : public testing::Test {
    }
    ASSERT_OK(s);
    // Make "CURRENT" file that points to the new manifest file.
-    s = SetCurrentFile(env_, dbname_, 1, nullptr);
+    s = SetCurrentFile(fs_.get(), dbname_, 1, nullptr);

    std::vector<ColumnFamilyDescriptor> column_families;
    cf_options_.table_factory = mock_table_factory_;
@@ -314,11 +314,11 @@ class CompactionJobTest : public testing::Test {
      num_input_files += level_files.size();
    }

-    Compaction compaction(cfd->current()->storage_info(), *cfd->ioptions(),
-                          *cfd->GetLatestMutableCFOptions(),
-                          compaction_input_files, output_level, 1024 * 1024,
-                          10 * 1024 * 1024, 0, kNoCompression,
-                          cfd->ioptions()->compression_opts, 0, {}, true);
+    Compaction compaction(
+        cfd->current()->storage_info(), *cfd->ioptions(),
+        *cfd->GetLatestMutableCFOptions(), compaction_input_files, output_level,
+        1024 * 1024, 10 * 1024 * 1024, 0, kNoCompression,
+        cfd->GetLatestMutableCFOptions()->compression_opts, 0, {}, true);
    compaction.SetInputVersion(cfd->current());

    LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, db_options_.info_log.get());
@@ -395,7 +395,7 @@ TEST_F(CompactionJobTest, Simple) {
  RunCompaction({ files }, expected_results);
 }

-TEST_F(CompactionJobTest, SimpleCorrupted) {
+TEST_F(CompactionJobTest, DISABLED_SimpleCorrupted) {
  NewDB();

  auto expected_results = CreateTwoFiles(true);
@@ -989,7 +989,7 @@ TEST_F(CompactionJobTest, MultiSingleDelete) {
 // single deletion and the (single) deletion gets removed while the corrupt key
 // gets written out. TODO(noetzli): We probably want a better way to treat
 // corrupt keys.
-TEST_F(CompactionJobTest, CorruptionAfterDeletion) {
+TEST_F(CompactionJobTest, DISABLED_CorruptionAfterDeletion) {
  NewDB();

  auto file1 =
@@ -110,9 +110,9 @@ CompressionType GetCompressionType(const ImmutableCFOptions& ioptions,

  // If bottommost_compression is set and we are compacting to the
  // bottommost level then we should use it.
-  if (ioptions.bottommost_compression != kDisableCompressionOption &&
+  if (mutable_cf_options.bottommost_compression != kDisableCompressionOption &&
      level >= (vstorage->num_non_empty_levels() - 1)) {
-    return ioptions.bottommost_compression;
+    return mutable_cf_options.bottommost_compression;
  }
  // If the user has specified a different compression level for each level,
  // then pick the compression for that level.
@@ -132,22 +132,22 @@ CompressionType GetCompressionType(const ImmutableCFOptions& ioptions,
  }
 }

-CompressionOptions GetCompressionOptions(const ImmutableCFOptions& ioptions,
+CompressionOptions GetCompressionOptions(const MutableCFOptions& cf_options,
                                         const VersionStorageInfo* vstorage,
                                         int level,
                                         const bool enable_compression) {
  if (!enable_compression) {
-    return ioptions.compression_opts;
+    return cf_options.compression_opts;
  }
  // If bottommost_compression is set and we are compacting to the
  // bottommost level then we should use the specified compression options
  // for the bottmomost_compression.
-  if (ioptions.bottommost_compression != kDisableCompressionOption &&
+  if (cf_options.bottommost_compression != kDisableCompressionOption &&
      level >= (vstorage->num_non_empty_levels() - 1) &&
-      ioptions.bottommost_compression_opts.enabled) {
-    return ioptions.bottommost_compression_opts;
+      cf_options.bottommost_compression_opts.enabled) {
+    return cf_options.bottommost_compression_opts;
  }
-  return ioptions.compression_opts;
+  return cf_options.compression_opts;
 }

 CompactionPicker::CompactionPicker(const ImmutableCFOptions& ioptions,
@@ -359,7 +359,7 @@ Compaction* CompactionPicker::CompactFiles(
      vstorage, ioptions_, mutable_cf_options, input_files, output_level,
      compact_options.output_file_size_limit,
      mutable_cf_options.max_compaction_bytes, output_path_id, compression_type,
-      GetCompressionOptions(ioptions_, vstorage, output_level),
+      GetCompressionOptions(mutable_cf_options, vstorage, output_level),
      compact_options.max_subcompactions,
      /* grandparents */ {}, true);
  RegisterCompaction(c);
@@ -634,7 +634,7 @@ Compaction* CompactionPicker::CompactRange(
        compact_range_options.target_path_id,
        GetCompressionType(ioptions_, vstorage, mutable_cf_options,
                           output_level, 1),
-        GetCompressionOptions(ioptions_, vstorage, output_level),
+        GetCompressionOptions(mutable_cf_options, vstorage, output_level),
        compact_range_options.max_subcompactions, /* grandparents */ {},
        /* is manual */ true);
    RegisterCompaction(c);
@@ -787,7 +787,7 @@ Compaction* CompactionPicker::CompactRange(
      compact_range_options.target_path_id,
      GetCompressionType(ioptions_, vstorage, mutable_cf_options, output_level,
                         vstorage->base_level()),
-      GetCompressionOptions(ioptions_, vstorage, output_level),
+      GetCompressionOptions(mutable_cf_options, vstorage, output_level),
      compact_range_options.max_subcompactions, std::move(grandparents),
      /* is manual compaction */ true);

@@ -1085,6 +1085,8 @@ void CompactionPicker::PickFilesMarkedForCompaction(
  Random64 rnd(/* seed */ reinterpret_cast<uint64_t>(vstorage));
  size_t random_file_index = static_cast<size_t>(rnd.Uniform(
      static_cast<uint64_t>(vstorage->FilesMarkedForCompaction().size())));
+  TEST_SYNC_POINT_CALLBACK("CompactionPicker::PickFilesMarkedForCompaction",
+                           &random_file_index);

  if (continuation(vstorage->FilesMarkedForCompaction()[random_file_index])) {
    // found the compaction!
@@ -305,9 +305,9 @@ CompressionType GetCompressionType(const ImmutableCFOptions& ioptions,
                                   int level, int base_level,
                                   const bool enable_compression = true);

-CompressionOptions GetCompressionOptions(const ImmutableCFOptions& ioptions,
-                                         const VersionStorageInfo* vstorage,
-                                         int level,
-                                         const bool enable_compression = true);
+CompressionOptions GetCompressionOptions(
+    const MutableCFOptions& mutable_cf_options,
+    const VersionStorageInfo* vstorage, int level,
+    const bool enable_compression = true);

 }  // namespace ROCKSDB_NAMESPACE
@@ -71,10 +71,14 @@ Compaction* FIFOCompactionPicker::PickTTLCompaction(
  if (current_time > mutable_cf_options.ttl) {
    for (auto ritr = level_files.rbegin(); ritr != level_files.rend(); ++ritr) {
      FileMetaData* f = *ritr;
-      uint64_t creation_time = f->TryGetFileCreationTime();
-      if (creation_time == kUnknownFileCreationTime ||
-          creation_time >= (current_time - mutable_cf_options.ttl)) {
-        break;
+      assert(f);
+      if (f->fd.table_reader && f->fd.table_reader->GetTableProperties()) {
+        uint64_t creation_time =
+            f->fd.table_reader->GetTableProperties()->creation_time;
+        if (creation_time == 0 ||
+            creation_time >= (current_time - mutable_cf_options.ttl)) {
+          break;
+        }
      }
      total_size -= f->compensated_file_size;
      inputs[0].files.push_back(f);
@@ -92,17 +96,22 @@ Compaction* FIFOCompactionPicker::PickTTLCompaction(
  }

  for (const auto& f : inputs[0].files) {
+    uint64_t creation_time = 0;
+    assert(f);
+    if (f->fd.table_reader && f->fd.table_reader->GetTableProperties()) {
+      creation_time = f->fd.table_reader->GetTableProperties()->creation_time;
+    }
    ROCKS_LOG_BUFFER(log_buffer,
                     "[%s] FIFO compaction: picking file %" PRIu64
                     " with creation time %" PRIu64 " for deletion",
-                     cf_name.c_str(), f->fd.GetNumber(),
-                     f->TryGetFileCreationTime());
+                     cf_name.c_str(), f->fd.GetNumber(), creation_time);
  }

  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs), 0, 0, 0, 0,
-      kNoCompression, ioptions_.compression_opts, /* max_subcompactions */ 0,
-      {}, /* is manual */ false, vstorage->CompactionScore(0),
+      kNoCompression, mutable_cf_options.compression_opts,
+      /* max_subcompactions */ 0, {}, /* is manual */ false,
+      vstorage->CompactionScore(0),
      /* is deletion compaction */ true, CompactionReason::kFIFOTtl);
  return c;
 }
@@ -142,7 +151,7 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(
            16 * 1024 * 1024 /* output file size limit */,
            0 /* max compaction bytes, not applicable */,
            0 /* output path ID */, mutable_cf_options.compression,
-            ioptions_.compression_opts, 0 /* max_subcompactions */, {},
+            mutable_cf_options.compression_opts, 0 /* max_subcompactions */, {},
            /* is manual */ false, vstorage->CompactionScore(0),
            /* is deletion compaction */ false,
            CompactionReason::kFIFOReduceNumFiles);
@@ -190,8 +199,9 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(

  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs), 0, 0, 0, 0,
-      kNoCompression, ioptions_.compression_opts, /* max_subcompactions */ 0,
-      {}, /* is manual */ false, vstorage->CompactionScore(0),
+      kNoCompression, mutable_cf_options.compression_opts,
+      /* max_subcompactions */ 0, {}, /* is manual */ false,
+      vstorage->CompactionScore(0),
      /* is deletion compaction */ true, CompactionReason::kFIFOMaxSize);
  return c;
 }
@@ -93,9 +93,13 @@ class LevelCompactionBuilder {
  // otherwise, returns false.
  bool PickIntraL0Compaction();

-  void PickExpiredTtlFiles();
-
-  void PickFilesMarkedForPeriodicCompaction();
+  // Picks a file from level_files to compact.
+  // level_files is a vector of (level, file metadata) in ascending order of
+  // level. If compact_to_next_level is true, compact the file to the next
+  // level, otherwise, compact to the same level as the input file.
+  void PickFileToCompact(
+      const autovector<std::pair<int, FileMetaData*>>& level_files,
+      bool compact_to_next_level);

  const std::string& cf_name_;
  VersionStorageInfo* vstorage_;
@@ -124,72 +128,34 @@ class LevelCompactionBuilder {
  static const int kMinFilesForIntraL0Compaction = 4;
 };

-void LevelCompactionBuilder::PickExpiredTtlFiles() {
-  if (vstorage_->ExpiredTtlFiles().empty()) {
-    return;
-  }
-
-  auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
+void LevelCompactionBuilder::PickFileToCompact(
+    const autovector<std::pair<int, FileMetaData*>>& level_files,
+    bool compact_to_next_level) {
+  for (auto& level_file : level_files) {
    // If it's being compacted it has nothing to do here.
    // If this assert() fails that means that some function marked some
    // files as being_compacted, but didn't call ComputeCompactionScore()
    assert(!level_file.second->being_compacted);
    start_level_ = level_file.first;
-    output_level_ =
-        (start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
-
-    if ((start_level_ == vstorage_->num_non_empty_levels() - 1) ||
+    if ((compact_to_next_level &&
+         start_level_ == vstorage_->num_non_empty_levels() - 1) ||
        (start_level_ == 0 &&
         !compaction_picker_->level0_compactions_in_progress()->empty())) {
-      return false;
+      continue;
+    }
+    if (compact_to_next_level) {
+      output_level_ =
+          (start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
+    } else {
+      output_level_ = start_level_;
    }
-
    start_level_inputs_.files = {level_file.second};
    start_level_inputs_.level = start_level_;
-    return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
-                                                      &start_level_inputs_);
-  };
-
-  for (auto& level_file : vstorage_->ExpiredTtlFiles()) {
-    if (continuation(level_file)) {
-      // found the compaction!
+    if (compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
+                                                   &start_level_inputs_)) {
      return;
    }
  }
-
-  start_level_inputs_.files.clear();
-}
-
-void LevelCompactionBuilder::PickFilesMarkedForPeriodicCompaction() {
-  if (vstorage_->FilesMarkedForPeriodicCompaction().empty()) {
-    return;
-  }
-
-  auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
-    // If it's being compacted it has nothing to do here.
-    // If this assert() fails that means that some function marked some
-    // files as being_compacted, but didn't call ComputeCompactionScore()
-    assert(!level_file.second->being_compacted);
-    output_level_ = start_level_ = level_file.first;
-
-    if (start_level_ == 0 &&
-        !compaction_picker_->level0_compactions_in_progress()->empty()) {
-      return false;
-    }
-
-    start_level_inputs_.files = {level_file.second};
-    start_level_inputs_.level = start_level_;
-    return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
-                                                      &start_level_inputs_);
-  };
-
-  for (auto& level_file : vstorage_->FilesMarkedForPeriodicCompaction()) {
-    if (continuation(level_file)) {
-      // found the compaction!
-      return;
-    }
-  }
-
  start_level_inputs_.files.clear();
 }

@@ -238,64 +204,46 @@ void LevelCompactionBuilder::SetupInitialFiles() {
          }
        }
      }
+    } else {
+      // Compaction scores are sorted in descending order, no further scores
+      // will be >= 1.
+      break;
    }
  }
+  if (!start_level_inputs_.empty()) {
+    return;
+  }

  // if we didn't find a compaction, check if there are any files marked for
  // compaction
-  if (start_level_inputs_.empty()) {
-    parent_index_ = base_index_ = -1;
+  parent_index_ = base_index_ = -1;

-    compaction_picker_->PickFilesMarkedForCompaction(
-        cf_name_, vstorage_, &start_level_, &output_level_,
-        &start_level_inputs_);
-    if (!start_level_inputs_.empty()) {
-      is_manual_ = true;
-      compaction_reason_ = CompactionReason::kFilesMarkedForCompaction;
-      return;
-    }
+  compaction_picker_->PickFilesMarkedForCompaction(
+      cf_name_, vstorage_, &start_level_, &output_level_, &start_level_inputs_);
+  if (!start_level_inputs_.empty()) {
+    compaction_reason_ = CompactionReason::kFilesMarkedForCompaction;
+    return;
  }

  // Bottommost Files Compaction on deleting tombstones
-  if (start_level_inputs_.empty()) {
-    size_t i;
-    for (i = 0; i < vstorage_->BottommostFilesMarkedForCompaction().size();
-         ++i) {
-      auto& level_and_file = vstorage_->BottommostFilesMarkedForCompaction()[i];
-      assert(!level_and_file.second->being_compacted);
-      start_level_inputs_.level = output_level_ = start_level_ =
-          level_and_file.first;
-      start_level_inputs_.files = {level_and_file.second};
-      if (compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
-                                                     &start_level_inputs_)) {
-        break;
-      }
-    }
-    if (i == vstorage_->BottommostFilesMarkedForCompaction().size()) {
-      start_level_inputs_.clear();
-    } else {
-      assert(!start_level_inputs_.empty());
-      compaction_reason_ = CompactionReason::kBottommostFiles;
-      return;
-    }
+  PickFileToCompact(vstorage_->BottommostFilesMarkedForCompaction(), false);
+  if (!start_level_inputs_.empty()) {
+    compaction_reason_ = CompactionReason::kBottommostFiles;
+    return;
  }

  // TTL Compaction
-  if (start_level_inputs_.empty()) {
-    PickExpiredTtlFiles();
-    if (!start_level_inputs_.empty()) {
-      compaction_reason_ = CompactionReason::kTtl;
-      return;
-    }
+  PickFileToCompact(vstorage_->ExpiredTtlFiles(), true);
+  if (!start_level_inputs_.empty()) {
+    compaction_reason_ = CompactionReason::kTtl;
+    return;
  }

  // Periodic Compaction
-  if (start_level_inputs_.empty()) {
-    PickFilesMarkedForPeriodicCompaction();
-    if (!start_level_inputs_.empty()) {
-      compaction_reason_ = CompactionReason::kPeriodicCompaction;
-      return;
-    }
+  PickFileToCompact(vstorage_->FilesMarkedForPeriodicCompaction(), false);
+  if (!start_level_inputs_.empty()) {
+    compaction_reason_ = CompactionReason::kPeriodicCompaction;
+    return;
  }
 }

@@ -384,7 +332,7 @@ Compaction* LevelCompactionBuilder::GetCompaction() {
      GetPathId(ioptions_, mutable_cf_options_, output_level_),
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level_, vstorage_->base_level()),
-      GetCompressionOptions(ioptions_, vstorage_, output_level_),
+      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level_),
      /* max_subcompactions */ 0, std::move(grandparents_), is_manual_,
      start_level_score_, false /* deletion_compaction */, compaction_reason_);

@@ -78,8 +78,17 @@ class CompactionPickerTest : public testing::Test {
    vstorage_->CalculateBaseBytes(ioptions_, mutable_cf_options_);
  }

+  // Create a new VersionStorageInfo object so we can add mode files and then
+  // merge it with the existing VersionStorageInfo
+  void AddVersionStorage() {
+    temp_vstorage_.reset(new VersionStorageInfo(
+        &icmp_, ucmp_, options_.num_levels, ioptions_.compaction_style,
+        vstorage_.get(), false));
+  }
+
  void DeleteVersionStorage() {
    vstorage_.reset();
+    temp_vstorage_.reset();
    files_.clear();
    file_map_.clear();
    input_files_.clear();
@@ -88,18 +97,24 @@ class CompactionPickerTest : public testing::Test {
  void Add(int level, uint32_t file_number, const char* smallest,
           const char* largest, uint64_t file_size = 1, uint32_t path_id = 0,
           SequenceNumber smallest_seq = 100, SequenceNumber largest_seq = 100,
-           size_t compensated_file_size = 0) {
-    assert(level < vstorage_->num_levels());
+           size_t compensated_file_size = 0, bool marked_for_compact = false) {
+    VersionStorageInfo* vstorage;
+    if (temp_vstorage_) {
+      vstorage = temp_vstorage_.get();
+    } else {
+      vstorage = vstorage_.get();
+    }
+    assert(level < vstorage->num_levels());
    FileMetaData* f = new FileMetaData(
        file_number, path_id, file_size,
        InternalKey(smallest, smallest_seq, kTypeValue),
        InternalKey(largest, largest_seq, kTypeValue), smallest_seq,
-        largest_seq, /* marked_for_compact */ false, kInvalidBlobFileNumber,
+        largest_seq, marked_for_compact, kInvalidBlobFileNumber,
        kUnknownOldestAncesterTime, kUnknownFileCreationTime,
        kUnknownFileChecksum, kUnknownFileChecksumFuncName);
    f->compensated_file_size =
        (compensated_file_size != 0) ? compensated_file_size : file_size;
-    vstorage_->AddFile(level, f);
+    vstorage->AddFile(level, f);
    files_.emplace_back(f);
    file_map_.insert({file_number, {f, level}});
  }
@@ -122,6 +137,12 @@ class CompactionPickerTest : public testing::Test {
  }

  void UpdateVersionStorageInfo() {
+    if (temp_vstorage_) {
+      VersionBuilder builder(FileOptions(), &ioptions_, nullptr,
+                             vstorage_.get(), nullptr);
+      builder.SaveTo(temp_vstorage_.get());
+      vstorage_ = std::move(temp_vstorage_);
+    }
    vstorage_->CalculateBaseBytes(ioptions_, mutable_cf_options_);
    vstorage_->UpdateFilesByCompactionPri(ioptions_.compaction_pri);
    vstorage_->UpdateNumNonEmptyLevels();
@@ -132,6 +153,28 @@ class CompactionPickerTest : public testing::Test {
    vstorage_->ComputeFilesMarkedForCompaction();
    vstorage_->SetFinalized();
  }
+  void AddFileToVersionStorage(int level, uint32_t file_number,
+                               const char* smallest, const char* largest,
+                               uint64_t file_size = 1, uint32_t path_id = 0,
+                               SequenceNumber smallest_seq = 100,
+                               SequenceNumber largest_seq = 100,
+                               size_t compensated_file_size = 0,
+                               bool marked_for_compact = false) {
+    VersionStorageInfo* base_vstorage = vstorage_.release();
+    vstorage_.reset(new VersionStorageInfo(&icmp_, ucmp_, options_.num_levels,
+                                           kCompactionStyleUniversal,
+                                           base_vstorage, false));
+    Add(level, file_number, smallest, largest, file_size, path_id, smallest_seq,
+        largest_seq, compensated_file_size, marked_for_compact);
+
+    VersionBuilder builder(FileOptions(), &ioptions_, nullptr, base_vstorage,
+                           nullptr);
+    builder.SaveTo(vstorage_.get());
+    UpdateVersionStorageInfo();
+  }
+
+ private:
+  std::unique_ptr<VersionStorageInfo> temp_vstorage_;
 };

 TEST_F(CompactionPickerTest, Empty) {
@@ -371,8 +414,8 @@ TEST_F(CompactionPickerTest, LevelTriggerDynamic4) {
  mutable_cf_options_.max_bytes_for_level_multiplier = 10;
  NewVersionStorage(num_levels, kCompactionStyleLevel);
  Add(0, 1U, "150", "200");
-  Add(num_levels - 1, 3U, "200", "250", 300U);
-  Add(num_levels - 1, 4U, "300", "350", 3000U);
+  Add(num_levels - 1, 2U, "200", "250", 300U);
+  Add(num_levels - 1, 3U, "300", "350", 3000U);
  Add(num_levels - 1, 4U, "400", "450", 3U);
  Add(num_levels - 2, 5U, "150", "180", 300U);
  Add(num_levels - 2, 6U, "181", "350", 500U);
@@ -739,7 +782,7 @@ TEST_F(CompactionPickerTest, CompactionPriMinOverlapping2) {
  Add(2, 8U, "201", "300",
      60000000U);  // Overlaps with file 28, 29, total size 521M

-  Add(3, 26U, "100", "110", 261000000U);
+  Add(3, 25U, "100", "110", 261000000U);
  Add(3, 26U, "150", "170", 261000000U);
  Add(3, 27U, "171", "179", 260000000U);
  Add(3, 28U, "191", "220", 260000000U);
@@ -1255,7 +1298,7 @@ TEST_F(CompactionPickerTest, EstimateCompactionBytesNeeded1) {
  // Size ratio L4/L3 is 9.9
  // After merge from L3, L4 size is 1000900
  Add(4, 11U, "400", "500", 999900);
-  Add(5, 11U, "400", "500", 8007200);
+  Add(5, 12U, "400", "500", 8007200);

  UpdateVersionStorageInfo();

@@ -1568,8 +1611,8 @@ TEST_F(CompactionPickerTest, IsTrivialMoveOn) {

  Add(3, 5U, "120", "130", 7000U);
  Add(3, 6U, "170", "180", 7000U);
-  Add(3, 5U, "220", "230", 7000U);
-  Add(3, 5U, "270", "280", 7000U);
+  Add(3, 7U, "220", "230", 7000U);
+  Add(3, 8U, "270", "280", 7000U);
  UpdateVersionStorageInfo();

  std::unique_ptr<Compaction> compaction(level_compaction_picker.PickCompaction(
@@ -1733,6 +1776,165 @@ TEST_F(CompactionPickerTest, IntraL0ForEarliestSeqno) {
  ASSERT_EQ(0, compaction->output_level());
 }

+#ifndef ROCKSDB_LITE
+TEST_F(CompactionPickerTest, UniversalMarkedCompactionFullOverlap) {
+  const uint64_t kFileSize = 100000;
+
+  ioptions_.compaction_style = kCompactionStyleUniversal;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  // This test covers the case where a "regular" universal compaction is
+  // scheduled first, followed by a delete triggered compaction. The latter
+  // should fail
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(0, 2U, "201", "250", 2 * kFileSize, 0, 401, 450);
+  Add(0, 4U, "260", "300", 4 * kFileSize, 0, 260, 300);
+  Add(3, 5U, "010", "080", 8 * kFileSize, 0, 200, 251);
+  Add(4, 3U, "301", "350", 8 * kFileSize, 0, 101, 150);
+  Add(4, 6U, "501", "750", 8 * kFileSize, 0, 101, 150);
+
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+
+  ASSERT_TRUE(compaction);
+  // Validate that its a compaction to reduce sorted runs
+  ASSERT_EQ(CompactionReason::kUniversalSortedRunNum,
+            compaction->compaction_reason());
+  ASSERT_EQ(0, compaction->output_level());
+  ASSERT_EQ(0, compaction->start_level());
+  ASSERT_EQ(2U, compaction->num_input_files(0));
+
+  AddVersionStorage();
+  // Simulate a flush and mark the file for compaction
+  Add(0, 7U, "150", "200", kFileSize, 0, 551, 600, 0, true);
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction2(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_FALSE(compaction2);
+}
+
+TEST_F(CompactionPickerTest, UniversalMarkedCompactionFullOverlap2) {
+  const uint64_t kFileSize = 100000;
+
+  ioptions_.compaction_style = kCompactionStyleUniversal;
+  UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+
+  // This test covers the case where a delete triggered compaction is
+  // scheduled first, followed by a "regular" compaction. The latter
+  // should fail
+  NewVersionStorage(5, kCompactionStyleUniversal);
+
+  // Mark file number 4 for compaction
+  Add(0, 4U, "260", "300", 4 * kFileSize, 0, 260, 300, 0, true);
+  Add(3, 5U, "240", "290", 8 * kFileSize, 0, 201, 250);
+  Add(4, 3U, "301", "350", 8 * kFileSize, 0, 101, 150);
+  Add(4, 6U, "501", "750", 8 * kFileSize, 0, 101, 150);
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+
+  ASSERT_TRUE(compaction);
+  // Validate that its a delete triggered compaction
+  ASSERT_EQ(CompactionReason::kFilesMarkedForCompaction,
+            compaction->compaction_reason());
+  ASSERT_EQ(3, compaction->output_level());
+  ASSERT_EQ(0, compaction->start_level());
+  ASSERT_EQ(1U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->num_input_files(1));
+
+  AddVersionStorage();
+  Add(0, 1U, "150", "200", kFileSize, 0, 500, 550);
+  Add(0, 2U, "201", "250", 2 * kFileSize, 0, 401, 450);
+  UpdateVersionStorageInfo();
+
+  std::unique_ptr<Compaction> compaction2(
+      universal_compaction_picker.PickCompaction(
+          cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+  ASSERT_FALSE(compaction2);
+}
+
+TEST_F(CompactionPickerTest, UniversalMarkedCompactionStartOutputOverlap) {
+  // The case where universal periodic compaction can be picked
+  // with some newer files being compacted.
+  const uint64_t kFileSize = 100000;
+
+  ioptions_.compaction_style = kCompactionStyleUniversal;
+
+  bool input_level_overlap = false;
+  bool output_level_overlap = false;
+  // Let's mark 2 files in 2 different levels for compaction. The
+  // compaction picker will randomly pick one, so use the sync point to
+  // ensure a deterministic order. Loop until both cases are covered
+  size_t random_index = 0;
+  SyncPoint::GetInstance()->SetCallBack(
+      "CompactionPicker::PickFilesMarkedForCompaction", [&](void* arg) {
+        size_t* index = static_cast<size_t*>(arg);
+        *index = random_index;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  while (!input_level_overlap || !output_level_overlap) {
+    // Ensure that the L0 file gets picked first
+    random_index = !input_level_overlap ? 0 : 1;
+    UniversalCompactionPicker universal_compaction_picker(ioptions_, &icmp_);
+    NewVersionStorage(5, kCompactionStyleUniversal);
+
+    Add(0, 1U, "260", "300", 4 * kFileSize, 0, 260, 300, 0, true);
+    Add(3, 2U, "010", "020", 2 * kFileSize, 0, 201, 248);
+    Add(3, 3U, "250", "270", 2 * kFileSize, 0, 202, 249);
+    Add(3, 4U, "290", "310", 2 * kFileSize, 0, 203, 250);
+    Add(3, 5U, "310", "320", 2 * kFileSize, 0, 204, 251, 0, true);
+    Add(4, 6U, "301", "350", 8 * kFileSize, 0, 101, 150);
+    Add(4, 7U, "501", "750", 8 * kFileSize, 0, 101, 150);
+    UpdateVersionStorageInfo();
+
+    std::unique_ptr<Compaction> compaction(
+        universal_compaction_picker.PickCompaction(
+            cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+
+    ASSERT_TRUE(compaction);
+    // Validate that its a delete triggered compaction
+    ASSERT_EQ(CompactionReason::kFilesMarkedForCompaction,
+              compaction->compaction_reason());
+    ASSERT_TRUE(compaction->start_level() == 0 ||
+                compaction->start_level() == 3);
+    if (compaction->start_level() == 0) {
+      // The L0 file was picked. The next compaction will detect an
+      // overlap on its input level
+      input_level_overlap = true;
+      ASSERT_EQ(3, compaction->output_level());
+      ASSERT_EQ(1U, compaction->num_input_files(0));
+      ASSERT_EQ(3U, compaction->num_input_files(1));
+    } else {
+      // The level 3 file was picked. The next compaction will pick
+      // the L0 file and will detect overlap when adding output
+      // level inputs
+      output_level_overlap = true;
+      ASSERT_EQ(4, compaction->output_level());
+      ASSERT_EQ(2U, compaction->num_input_files(0));
+      ASSERT_EQ(1U, compaction->num_input_files(1));
+    }
+
+    vstorage_->ComputeCompactionScore(ioptions_, mutable_cf_options_);
+    // After recomputing the compaction score, only one marked file will remain
+    random_index = 0;
+    std::unique_ptr<Compaction> compaction2(
+        universal_compaction_picker.PickCompaction(
+            cf_name_, mutable_cf_options_, vstorage_.get(), &log_buffer_));
+    ASSERT_FALSE(compaction2);
+    DeleteVersionStorage();
+  }
+}
+#endif  // ROCKSDB_LITE
+
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
@@ -120,8 +120,7 @@ class UniversalCompactionBuilder {
  LogBuffer* log_buffer_;

  static std::vector<SortedRun> CalculateSortedRuns(
-      const VersionStorageInfo& vstorage, const ImmutableCFOptions& ioptions,
-      const MutableCFOptions& mutable_cf_options);
+      const VersionStorageInfo& vstorage);

  // Pick a path ID to place a newly generated file, with its estimated file
  // size.
@@ -325,8 +324,7 @@ void UniversalCompactionBuilder::SortedRun::DumpSizeInfo(

 std::vector<UniversalCompactionBuilder::SortedRun>
 UniversalCompactionBuilder::CalculateSortedRuns(
-    const VersionStorageInfo& vstorage, const ImmutableCFOptions& /*ioptions*/,
-    const MutableCFOptions& mutable_cf_options) {
+    const VersionStorageInfo& vstorage) {
  std::vector<UniversalCompactionBuilder::SortedRun> ret;
  for (FileMetaData* f : vstorage.LevelFiles(0)) {
    ret.emplace_back(0, f, f->fd.GetFileSize(), f->compensated_file_size,
@@ -336,27 +334,16 @@ UniversalCompactionBuilder::CalculateSortedRuns(
    uint64_t total_compensated_size = 0U;
    uint64_t total_size = 0U;
    bool being_compacted = false;
-    bool is_first = true;
    for (FileMetaData* f : vstorage.LevelFiles(level)) {
      total_compensated_size += f->compensated_file_size;
      total_size += f->fd.GetFileSize();
-      if (mutable_cf_options.compaction_options_universal.allow_trivial_move ==
-          true) {
-        if (f->being_compacted) {
-          being_compacted = f->being_compacted;
-        }
-      } else {
-        // Compaction always includes all files for a non-zero level, so for a
-        // non-zero level, all the files should share the same being_compacted
-        // value.
-        // This assumption is only valid when
-        // mutable_cf_options.compaction_options_universal.allow_trivial_move
-        // is false
-        assert(is_first || f->being_compacted == being_compacted);
-      }
-      if (is_first) {
+      // Size amp, read amp and periodic compactions always include all files
+      // for a non-zero level. However, a delete triggered compaction and
+      // a trivial move might pick a subset of files in a sorted run. So
+      // always check all files in a sorted run and mark the entire run as
+      // being compacted if one or more files are being compacted
+      if (f->being_compacted) {
        being_compacted = f->being_compacted;
-        is_first = false;
      }
    }
    if (total_compensated_size > 0) {
@@ -372,8 +359,7 @@ UniversalCompactionBuilder::CalculateSortedRuns(
 Compaction* UniversalCompactionBuilder::PickCompaction() {
  const int kLevel0 = 0;
  score_ = vstorage_->CompactionScore(kLevel0);
-  sorted_runs_ =
-      CalculateSortedRuns(*vstorage_, ioptions_, mutable_cf_options_);
+  sorted_runs_ = CalculateSortedRuns(*vstorage_);

  if (sorted_runs_.size() == 0 ||
      (vstorage_->FilesMarkedForPeriodicCompaction().empty() &&
@@ -389,7 +375,7 @@ Compaction* UniversalCompactionBuilder::PickCompaction() {
  VersionStorageInfo::LevelSummaryStorage tmp;
  ROCKS_LOG_BUFFER_MAX_SZ(
      log_buffer_, 3072,
-      "[%s] Universal: sorted runs files(%" ROCKSDB_PRIszt "): %s\n",
+      "[%s] Universal: sorted runs: %" ROCKSDB_PRIszt " files: %s\n",
      cf_name_.c_str(), sorted_runs_.size(), vstorage_->LevelSummary(&tmp));

  Compaction* c = nullptr;
@@ -751,7 +737,7 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSortedRuns(
      LLONG_MAX, path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_, start_level,
                         1, enable_compression),
-      GetCompressionOptions(ioptions_, vstorage_, start_level,
+      GetCompressionOptions(mutable_cf_options_, vstorage_, start_level,
                            enable_compression),
      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
      score_, false /* deletion_compaction */, compaction_reason);
@@ -779,7 +765,7 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSizeAmp() {
  }

  // Skip files that are already being compacted
-  for (size_t loop = 0; loop < sorted_runs_.size() - 1; loop++) {
+  for (size_t loop = 0; loop + 1 < sorted_runs_.size(); loop++) {
    sr = &sorted_runs_[loop];
    if (!sr->being_compacted) {
      start_index = loop;  // Consider this as the first candidate.
@@ -807,7 +793,7 @@ Compaction* UniversalCompactionBuilder::PickCompactionToReduceSizeAmp() {
  }

  // keep adding up all the remaining files
-  for (size_t loop = start_index; loop < sorted_runs_.size() - 1; loop++) {
+  for (size_t loop = start_index; loop + 1 < sorted_runs_.size(); loop++) {
    sr = &sorted_runs_[loop];
    if (sr->being_compacted) {
      char file_num_buf[kFormatFileNumberBufSize];
@@ -855,6 +841,7 @@ Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
  std::vector<CompactionInputFiles> inputs;

  if (vstorage_->num_levels() == 1) {
+#if defined(ENABLE_SINGLE_LEVEL_DTC)
    // This is single level universal. Since we're basically trying to reclaim
    // space by processing files marked for compaction due to high tombstone
    // density, let's do the same thing as compaction to reduce size amp which
@@ -877,6 +864,11 @@ Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
      return nullptr;
    }
    inputs.push_back(start_level_inputs);
+#else
+    // Disable due to a known race condition.
+    // TODO: Reenable once the race condition is fixed
+    return nullptr;
+#endif  // ENABLE_SINGLE_LEVEL_DTC
  } else {
    int start_level;

@@ -959,8 +951,8 @@ Compaction* UniversalCompactionBuilder::PickDeleteTriggeredCompaction() {
      /* max_grandparent_overlap_bytes */ LLONG_MAX, path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level, 1),
-      GetCompressionOptions(ioptions_, vstorage_, output_level),
-      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ true,
+      GetCompressionOptions(mutable_cf_options_, vstorage_, output_level),
+      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
      score_, false /* deletion_compaction */,
      CompactionReason::kFilesMarkedForCompaction);
 }
@@ -1029,7 +1021,7 @@ Compaction* UniversalCompactionBuilder::PickCompactionToOldest(
      LLONG_MAX, path_id,
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_, start_level,
                         1, true /* enable_compression */),
-      GetCompressionOptions(ioptions_, vstorage_, start_level,
+      GetCompressionOptions(mutable_cf_options_, vstorage_, start_level,
                            true /* enable_compression */),
      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
      score_, false /* deletion_compaction */, compaction_reason);
@@ -14,7 +14,7 @@
 namespace ROCKSDB_NAMESPACE {

 void CancelAllBackgroundWork(DB* db, bool wait) {
-  (static_cast_with_check<DBImpl, DB>(db->GetRootDB()))
+  (static_cast_with_check<DBImpl>(db->GetRootDB()))
      ->CancelAllBackgroundWork(wait);
 }

@@ -28,7 +28,7 @@ Status DeleteFilesInRange(DB* db, ColumnFamilyHandle* column_family,
 Status DeleteFilesInRanges(DB* db, ColumnFamilyHandle* column_family,
                           const RangePtr* ranges, size_t n,
                           bool include_end) {
-  return (static_cast_with_check<DBImpl, DB>(db->GetRootDB()))
+  return (static_cast_with_check<DBImpl>(db->GetRootDB()))
      ->DeleteFilesInRanges(column_family, ranges, n, include_end);
 }

@@ -61,7 +61,8 @@ Status VerifySstFileChecksum(const Options& options,
  s = ioptions.table_factory->NewTableReader(
      TableReaderOptions(ioptions, options.prefix_extractor.get(), env_options,
                         internal_comparator, false /* skip_filters */,
-                         !kImmortal, -1 /* level */),
+                         !kImmortal, false /* force_direct_prefetch */,
+                         -1 /* level */),
      std::move(file_reader), file_size, &table_reader,
      false /* prefetch_index_and_filter_in_cache */);
  if (!s.ok()) {
@@ -157,43 +157,6 @@ class CorruptionTest : public testing::Test {
    ASSERT_GE(max_expected, correct);
  }

-  void CorruptFile(const std::string& fname, int offset, int bytes_to_corrupt) {
-    struct stat sbuf;
-    if (stat(fname.c_str(), &sbuf) != 0) {
-      const char* msg = strerror(errno);
-      FAIL() << fname << ": " << msg;
-    }
-
-    if (offset < 0) {
-      // Relative to end of file; make it absolute
-      if (-offset > sbuf.st_size) {
-        offset = 0;
-      } else {
-        offset = static_cast<int>(sbuf.st_size + offset);
-      }
-    }
-    if (offset > sbuf.st_size) {
-      offset = static_cast<int>(sbuf.st_size);
-    }
-    if (offset + bytes_to_corrupt > sbuf.st_size) {
-      bytes_to_corrupt = static_cast<int>(sbuf.st_size - offset);
-    }
-
-    // Do it
-    std::string contents;
-    Status s = ReadFileToString(Env::Default(), fname, &contents);
-    ASSERT_TRUE(s.ok()) << s.ToString();
-    for (int i = 0; i < bytes_to_corrupt; i++) {
-      contents[i + offset] ^= 0x80;
-    }
-    s = WriteStringToFile(Env::Default(), contents, fname);
-    ASSERT_TRUE(s.ok()) << s.ToString();
-    Options options;
-    EnvOptions env_options;
-    options.file_system.reset(new LegacyFileSystemWrapper(options.env));
-    ASSERT_NOK(VerifySstFileChecksum(options, env_options, fname));
-  }
-
  void Corrupt(FileType filetype, int offset, int bytes_to_corrupt) {
    // Pick file to corrupt
    std::vector<std::string> filenames;
@@ -212,7 +175,7 @@ class CorruptionTest : public testing::Test {
    }
    ASSERT_TRUE(!fname.empty()) << filetype;

-    CorruptFile(fname, offset, bytes_to_corrupt);
+    test::CorruptFile(fname, offset, bytes_to_corrupt);
  }

  // corrupts exactly one file at level `level`. if no file found at level,
@@ -222,7 +185,7 @@ class CorruptionTest : public testing::Test {
    db_->GetLiveFilesMetaData(&metadata);
    for (const auto& m : metadata) {
      if (m.level == level) {
-        CorruptFile(dbname_ + "/" + m.name, offset, bytes_to_corrupt);
+        test::CorruptFile(dbname_ + "/" + m.name, offset, bytes_to_corrupt);
        return;
      }
    }
@@ -557,7 +520,7 @@ TEST_F(CorruptionTest, RangeDeletionCorrupted) {
      ImmutableCFOptions(options_), kRangeDelBlock, &range_del_handle));

  ASSERT_OK(TryReopen());
-  CorruptFile(filename, static_cast<int>(range_del_handle.offset()), 1);
+  test::CorruptFile(filename, static_cast<int>(range_del_handle.offset()), 1);
  ASSERT_TRUE(TryReopen().IsCorruption());
 }

@@ -187,7 +187,7 @@ TEST_F(DBBlockCacheTest, TestWithoutCompressedBlockCache) {
  Iterator* iter = nullptr;

  // Load blocks into cache.
-  for (size_t i = 0; i < kNumBlocks - 1; i++) {
+  for (size_t i = 0; i + 1 < kNumBlocks; i++) {
    iter = db_->NewIterator(read_options);
    iter->Seek(ToString(i));
    ASSERT_OK(iter->status());
@@ -209,12 +209,12 @@ TEST_F(DBBlockCacheTest, TestWithoutCompressedBlockCache) {
  iter = nullptr;

  // Release iterators and access cache again.
-  for (size_t i = 0; i < kNumBlocks - 1; i++) {
+  for (size_t i = 0; i + 1 < kNumBlocks; i++) {
    iterators[i].reset();
    CheckCacheCounters(options, 0, 0, 0, 0);
  }
  ASSERT_EQ(0, cache->GetPinnedUsage());
-  for (size_t i = 0; i < kNumBlocks - 1; i++) {
+  for (size_t i = 0; i + 1 < kNumBlocks; i++) {
    iter = db_->NewIterator(read_options);
    iter->Seek(ToString(i));
    ASSERT_OK(iter->status());
@@ -243,7 +243,7 @@ TEST_F(DBBlockCacheTest, TestWithCompressedBlockCache) {
  Iterator* iter = nullptr;

  // Load blocks into cache.
-  for (size_t i = 0; i < kNumBlocks - 1; i++) {
+  for (size_t i = 0; i + 1 < kNumBlocks; i++) {
    iter = db_->NewIterator(read_options);
    iter->Seek(ToString(i));
    ASSERT_OK(iter->status());
@@ -517,6 +517,139 @@ TEST_F(DBBlockCacheTest, IndexAndFilterBlocksCachePriority) {
  }
 }

+namespace {
+
+// An LRUCache wrapper that can falsely report "not found" on Lookup.
+// This allows us to manipulate BlockBasedTableReader into thinking
+// another thread inserted the data in between Lookup and Insert,
+// while mostly preserving the LRUCache interface/behavior.
+class LookupLiarCache : public CacheWrapper {
+  int nth_lookup_not_found_ = 0;
+
+ public:
+  explicit LookupLiarCache(std::shared_ptr<Cache> target)
+      : CacheWrapper(std::move(target)) {}
+
+  Handle* Lookup(const Slice& key, Statistics* stats) override {
+    if (nth_lookup_not_found_ == 1) {
+      nth_lookup_not_found_ = 0;
+      return nullptr;
+    }
+    if (nth_lookup_not_found_ > 1) {
+      --nth_lookup_not_found_;
+    }
+    return CacheWrapper::Lookup(key, stats);
+  }
+
+  // 1 == next lookup, 2 == after next, etc.
+  void SetNthLookupNotFound(int n) { nth_lookup_not_found_ = n; }
+};
+
+}  // anonymous namespace
+
+TEST_F(DBBlockCacheTest, AddRedundantStats) {
+  const size_t capacity = size_t{1} << 25;
+  const int num_shard_bits = 0;  // 1 shard
+  int iterations_tested = 0;
+  for (std::shared_ptr<Cache> base_cache :
+       {NewLRUCache(capacity, num_shard_bits),
+        NewClockCache(capacity, num_shard_bits)}) {
+    if (!base_cache) {
+      // Skip clock cache when not supported
+      continue;
+    }
+    ++iterations_tested;
+    Options options = CurrentOptions();
+    options.create_if_missing = true;
+    options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+
+    std::shared_ptr<LookupLiarCache> cache =
+        std::make_shared<LookupLiarCache>(base_cache);
+
+    BlockBasedTableOptions table_options;
+    table_options.cache_index_and_filter_blocks = true;
+    table_options.block_cache = cache;
+    table_options.filter_policy.reset(NewBloomFilterPolicy(50));
+    options.table_factory.reset(new BlockBasedTableFactory(table_options));
+    DestroyAndReopen(options);
+
+    // Create a new table.
+    ASSERT_OK(Put("foo", "value"));
+    ASSERT_OK(Put("bar", "value"));
+    ASSERT_OK(Flush());
+    ASSERT_EQ(1, NumTableFilesAtLevel(0));
+
+    // Normal access filter+index+data.
+    ASSERT_EQ("value", Get("foo"));
+
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
+    // --------
+    ASSERT_EQ(3, TestGetTickerCount(options, BLOCK_CACHE_ADD));
+
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
+    // --------
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
+
+    // Againt access filter+index+data, but force redundant load+insert on index
+    cache->SetNthLookupNotFound(2);
+    ASSERT_EQ("value", Get("bar"));
+
+    ASSERT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
+    // --------
+    ASSERT_EQ(4, TestGetTickerCount(options, BLOCK_CACHE_ADD));
+
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
+    ASSERT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
+    // --------
+    ASSERT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
+
+    // Access just filter (with high probability), and force redundant
+    // load+insert
+    cache->SetNthLookupNotFound(1);
+    ASSERT_EQ("NOT_FOUND", Get("this key was not added"));
+
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
+    // --------
+    EXPECT_EQ(5, TestGetTickerCount(options, BLOCK_CACHE_ADD));
+
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
+    EXPECT_EQ(0, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
+    // --------
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
+
+    // Access just data, forcing redundant load+insert
+    ReadOptions read_options;
+    std::unique_ptr<Iterator> iter{db_->NewIterator(read_options)};
+    cache->SetNthLookupNotFound(1);
+    iter->SeekToFirst();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_EQ(iter->key(), "bar");
+
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD));
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD));
+    EXPECT_EQ(2, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD));
+    // --------
+    EXPECT_EQ(6, TestGetTickerCount(options, BLOCK_CACHE_ADD));
+
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_ADD_REDUNDANT));
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_FILTER_ADD_REDUNDANT));
+    EXPECT_EQ(1, TestGetTickerCount(options, BLOCK_CACHE_DATA_ADD_REDUNDANT));
+    // --------
+    EXPECT_EQ(3, TestGetTickerCount(options, BLOCK_CACHE_ADD_REDUNDANT));
+  }
+  EXPECT_GE(iterations_tested, 1);
+}
+
 TEST_F(DBBlockCacheTest, ParanoidFileChecks) {
  Options options = CurrentOptions();
  options.create_if_missing = true;
@@ -8,6 +8,7 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.

 #include "db/db_test_util.h"
+#include "options/options_helper.h"
 #include "port/stack_trace.h"
 #include "rocksdb/perf_context.h"
 #include "table/block_based/filter_policy_internal.h"
@@ -1029,6 +1030,215 @@ TEST_F(DBBloomFilterTest, MemtablePrefixBloomOutOfDomain) {
  ASSERT_EQ(kKey, iter->key());
 }

+class DBBloomFilterTestVaryPrefixAndFormatVer
+    : public DBTestBase,
+      public testing::WithParamInterface<std::tuple<bool, uint32_t>> {
+ protected:
+  bool use_prefix_;
+  uint32_t format_version_;
+
+ public:
+  DBBloomFilterTestVaryPrefixAndFormatVer()
+      : DBTestBase("/db_bloom_filter_tests") {}
+
+  ~DBBloomFilterTestVaryPrefixAndFormatVer() override {}
+
+  void SetUp() override {
+    use_prefix_ = std::get<0>(GetParam());
+    format_version_ = std::get<1>(GetParam());
+  }
+
+  static std::string UKey(uint32_t i) { return Key(static_cast<int>(i)); }
+};
+
+TEST_P(DBBloomFilterTestVaryPrefixAndFormatVer, PartitionedMultiGet) {
+  Options options = CurrentOptions();
+  if (use_prefix_) {
+    // Entire key from UKey()
+    options.prefix_extractor.reset(NewCappedPrefixTransform(9));
+  }
+  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy.reset(NewBloomFilterPolicy(20));
+  bbto.partition_filters = true;
+  bbto.index_type = BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
+  bbto.whole_key_filtering = !use_prefix_;
+  if (use_prefix_) {  // (not related to prefix, just alternating between)
+    // Make sure code appropriately deals with metadata block size setting
+    // that is "too small" (smaller than minimum size for filter builder)
+    bbto.metadata_block_size = 63;
+  } else {
+    // Make sure the test will work even on platforms with large minimum
+    // filter size, due to large cache line size.
+    // (Largest cache line size + 10+% overhead.)
+    bbto.metadata_block_size = 290;
+  }
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  DestroyAndReopen(options);
+  ReadOptions ropts;
+
+  constexpr uint32_t N = 12000;
+  // Add N/2 evens
+  for (uint32_t i = 0; i < N; i += 2) {
+    ASSERT_OK(Put(UKey(i), UKey(i)));
+  }
+  ASSERT_OK(Flush());
+#ifndef ROCKSDB_LITE
+  ASSERT_EQ(TotalTableFiles(), 1);
+#endif
+
+  constexpr uint32_t Q = 29;
+  // MultiGet In
+  std::array<std::string, Q> keys;
+  std::array<Slice, Q> key_slices;
+  std::array<ColumnFamilyHandle*, Q> column_families;
+  // MultiGet Out
+  std::array<Status, Q> statuses;
+  std::array<PinnableSlice, Q> values;
+
+  TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_HIT);
+  TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
+  TestGetAndResetTickerCount(options, BLOOM_FILTER_PREFIX_USEFUL);
+  TestGetAndResetTickerCount(options, BLOOM_FILTER_USEFUL);
+  TestGetAndResetTickerCount(options, BLOOM_FILTER_PREFIX_CHECKED);
+  TestGetAndResetTickerCount(options, BLOOM_FILTER_FULL_POSITIVE);
+  TestGetAndResetTickerCount(options, BLOOM_FILTER_FULL_TRUE_POSITIVE);
+
+  // Check that initial clump of keys only loads one partition filter from
+  // block cache.
+  // And that spread out keys load many partition filters.
+  // In both cases, mix present vs. not present keys.
+  for (uint32_t stride : {uint32_t{1}, (N / Q) | 1}) {
+    for (uint32_t i = 0; i < Q; ++i) {
+      keys[i] = UKey(i * stride);
+      key_slices[i] = Slice(keys[i]);
+      column_families[i] = db_->DefaultColumnFamily();
+      statuses[i] = Status();
+      values[i] = PinnableSlice();
+    }
+
+    db_->MultiGet(ropts, Q, &column_families[0], &key_slices[0], &values[0],
+                  /*timestamps=*/nullptr, &statuses[0], true);
+
+    // Confirm correct status results
+    uint32_t number_not_found = 0;
+    for (uint32_t i = 0; i < Q; ++i) {
+      if ((i * stride % 2) == 0) {
+        ASSERT_OK(statuses[i]);
+      } else {
+        ASSERT_TRUE(statuses[i].IsNotFound());
+        ++number_not_found;
+      }
+    }
+
+    // Confirm correct Bloom stats (no FPs)
+    uint64_t filter_useful = TestGetAndResetTickerCount(
+        options,
+        use_prefix_ ? BLOOM_FILTER_PREFIX_USEFUL : BLOOM_FILTER_USEFUL);
+    uint64_t filter_checked =
+        TestGetAndResetTickerCount(options, use_prefix_
+                                                ? BLOOM_FILTER_PREFIX_CHECKED
+                                                : BLOOM_FILTER_FULL_POSITIVE) +
+        (use_prefix_ ? 0 : filter_useful);
+    EXPECT_EQ(filter_useful, number_not_found);
+    EXPECT_EQ(filter_checked, Q);
+    if (!use_prefix_) {
+      EXPECT_EQ(
+          TestGetAndResetTickerCount(options, BLOOM_FILTER_FULL_TRUE_POSITIVE),
+          Q - number_not_found);
+    }
+
+    // Confirm no duplicate loading same filter partition
+    uint64_t filter_accesses =
+        TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_HIT) +
+        TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
+    if (stride == 1) {
+      EXPECT_EQ(filter_accesses, 1);
+    } else {
+      // for large stride
+      EXPECT_GE(filter_accesses, Q / 2 + 1);
+    }
+  }
+
+  // Check that a clump of keys (present and not) works when spanning
+  // two partitions
+  int found_spanning = 0;
+  for (uint32_t start = 0; start < N / 2;) {
+    for (uint32_t i = 0; i < Q; ++i) {
+      keys[i] = UKey(start + i);
+      key_slices[i] = Slice(keys[i]);
+      column_families[i] = db_->DefaultColumnFamily();
+      statuses[i] = Status();
+      values[i] = PinnableSlice();
+    }
+
+    db_->MultiGet(ropts, Q, &column_families[0], &key_slices[0], &values[0],
+                  /*timestamps=*/nullptr, &statuses[0], true);
+
+    // Confirm correct status results
+    uint32_t number_not_found = 0;
+    for (uint32_t i = 0; i < Q; ++i) {
+      if (((start + i) % 2) == 0) {
+        ASSERT_OK(statuses[i]);
+      } else {
+        ASSERT_TRUE(statuses[i].IsNotFound());
+        ++number_not_found;
+      }
+    }
+
+    // Confirm correct Bloom stats (might see some FPs)
+    uint64_t filter_useful = TestGetAndResetTickerCount(
+        options,
+        use_prefix_ ? BLOOM_FILTER_PREFIX_USEFUL : BLOOM_FILTER_USEFUL);
+    uint64_t filter_checked =
+        TestGetAndResetTickerCount(options, use_prefix_
+                                                ? BLOOM_FILTER_PREFIX_CHECKED
+                                                : BLOOM_FILTER_FULL_POSITIVE) +
+        (use_prefix_ ? 0 : filter_useful);
+    EXPECT_GE(filter_useful, number_not_found - 2);  // possible FP
+    EXPECT_EQ(filter_checked, Q);
+    if (!use_prefix_) {
+      EXPECT_EQ(
+          TestGetAndResetTickerCount(options, BLOOM_FILTER_FULL_TRUE_POSITIVE),
+          Q - number_not_found);
+    }
+
+    // Confirm no duplicate loading of same filter partition
+    uint64_t filter_accesses =
+        TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_HIT) +
+        TestGetAndResetTickerCount(options, BLOCK_CACHE_FILTER_MISS);
+    if (filter_accesses == 2) {
+      // Spanned across partitions.
+      ++found_spanning;
+      if (found_spanning >= 2) {
+        break;
+      } else {
+        // Ensure that at least once we have at least one present and
+        // one non-present key on both sides of partition boundary.
+        start += 2;
+      }
+    } else {
+      EXPECT_EQ(filter_accesses, 1);
+      // See explanation at "start += 2"
+      start += Q - 4;
+    }
+  }
+  EXPECT_TRUE(found_spanning >= 2);
+}
+
+INSTANTIATE_TEST_CASE_P(DBBloomFilterTestVaryPrefixAndFormatVer,
+                        DBBloomFilterTestVaryPrefixAndFormatVer,
+                        ::testing::Values(
+                            // (use_prefix, format_version)
+                            std::make_tuple(false, 2),
+                            std::make_tuple(false, 3),
+                            std::make_tuple(false, 4),
+                            std::make_tuple(false, 5),
+                            std::make_tuple(true, 2),
+                            std::make_tuple(true, 3),
+                            std::make_tuple(true, 4),
+                            std::make_tuple(true, 5)));
+
 #ifndef ROCKSDB_LITE
 namespace {
 namespace BFP2 {
@@ -1343,8 +1553,7 @@ TEST_F(DBBloomFilterTest, OptimizeFiltersForHits) {
  for (int i = 0; i < numkeys; i += 2) {
    keys.push_back(i);
  }
-  std::random_shuffle(std::begin(keys), std::end(keys));
-
+  RandomShuffle(std::begin(keys), std::end(keys));
  int num_inserted = 0;
  for (int key : keys) {
    ASSERT_OK(Put(1, Key(key), "val"));
@@ -157,21 +157,21 @@ Options DeletionTriggerOptions(Options options) {
 bool HaveOverlappingKeyRanges(
    const Comparator* c,
    const SstFileMetaData& a, const SstFileMetaData& b) {
-  if (c->Compare(a.smallestkey, b.smallestkey) >= 0) {
-    if (c->Compare(a.smallestkey, b.largestkey) <= 0) {
+  if (c->CompareWithoutTimestamp(a.smallestkey, b.smallestkey) >= 0) {
+    if (c->CompareWithoutTimestamp(a.smallestkey, b.largestkey) <= 0) {
      // b.smallestkey <= a.smallestkey <= b.largestkey
      return true;
    }
-  } else if (c->Compare(a.largestkey, b.smallestkey) >= 0) {
+  } else if (c->CompareWithoutTimestamp(a.largestkey, b.smallestkey) >= 0) {
    // a.smallestkey < b.smallestkey <= a.largestkey
    return true;
  }
-  if (c->Compare(a.largestkey, b.largestkey) <= 0) {
-    if (c->Compare(a.largestkey, b.smallestkey) >= 0) {
+  if (c->CompareWithoutTimestamp(a.largestkey, b.largestkey) <= 0) {
+    if (c->CompareWithoutTimestamp(a.largestkey, b.smallestkey) >= 0) {
      // b.smallestkey <= a.largestkey <= b.largestkey
      return true;
    }
-  } else if (c->Compare(a.smallestkey, b.largestkey) <= 0) {
+  } else if (c->CompareWithoutTimestamp(a.smallestkey, b.largestkey) <= 0) {
    // a.smallestkey <= b.largestkey < a.largestkey
    return true;
  }
@@ -593,6 +593,72 @@ TEST_P(DBCompactionTestWithParam, CompactionDeletionTriggerReopen) {
  }
 }

+TEST_F(DBCompactionTest, CompactRangeBottomPri) {
+  ASSERT_OK(Put(Key(50), ""));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put(Key(100), ""));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put(Key(200), ""));
+  ASSERT_OK(Flush());
+
+  {
+    CompactRangeOptions cro;
+    cro.change_level = true;
+    cro.target_level = 2;
+    dbfull()->CompactRange(cro, nullptr, nullptr);
+  }
+  ASSERT_EQ("0,0,3", FilesPerLevel(0));
+
+  ASSERT_OK(Put(Key(1), ""));
+  ASSERT_OK(Put(Key(199), ""));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put(Key(2), ""));
+  ASSERT_OK(Put(Key(199), ""));
+  ASSERT_OK(Flush());
+  ASSERT_EQ("2,0,3", FilesPerLevel(0));
+
+  // Now we have 2 L0 files, and 3 L2 files, and a manual compaction will
+  // be triggered.
+  // Two compaction jobs will run. One compacts 2 L0 files in Low Pri Pool
+  // and one compact to L2 in bottom pri pool.
+  int low_pri_count = 0;
+  int bottom_pri_count = 0;
+  SyncPoint::GetInstance()->SetCallBack(
+      "ThreadPoolImpl::Impl::BGThread:BeforeRun", [&](void* arg) {
+        Env::Priority* pri = reinterpret_cast<Env::Priority*>(arg);
+        // First time is low pri pool in the test case.
+        if (low_pri_count == 0 && bottom_pri_count == 0) {
+          ASSERT_EQ(Env::Priority::LOW, *pri);
+        }
+        if (*pri == Env::Priority::LOW) {
+          low_pri_count++;
+        } else {
+          bottom_pri_count++;
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  env_->SetBackgroundThreads(1, Env::Priority::BOTTOM);
+  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+  ASSERT_EQ(1, low_pri_count);
+  ASSERT_EQ(1, bottom_pri_count);
+  ASSERT_EQ("0,0,2", FilesPerLevel(0));
+
+  // Recompact bottom most level uses bottom pool
+  CompactRangeOptions cro;
+  cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
+  dbfull()->CompactRange(cro, nullptr, nullptr);
+  ASSERT_EQ(1, low_pri_count);
+  ASSERT_EQ(2, bottom_pri_count);
+
+  env_->SetBackgroundThreads(0, Env::Priority::BOTTOM);
+  dbfull()->CompactRange(cro, nullptr, nullptr);
+  // Low pri pool is used if bottom pool has size 0.
+  ASSERT_EQ(2, low_pri_count);
+  ASSERT_EQ(2, bottom_pri_count);
+
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
 TEST_F(DBCompactionTest, DisableStatsUpdateReopen) {
  uint64_t db_size[3];
  for (int test = 0; test < 2; ++test) {
@@ -3118,6 +3184,15 @@ TEST_P(DBCompactionTestWithParam, IntraL0Compaction) {
  options.level0_file_num_compaction_trigger = 5;
  options.max_background_compactions = 2;
  options.max_subcompactions = max_subcompactions_;
+  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+  options.write_buffer_size = 2 << 20;  // 2MB
+
+  BlockBasedTableOptions table_options;
+  table_options.block_cache = NewLRUCache(64 << 20);  // 64MB
+  table_options.cache_index_and_filter_blocks = true;
+  table_options.pin_l0_filter_and_index_blocks_in_cache = true;
+  options.table_factory.reset(new BlockBasedTableFactory(table_options));
+
  DestroyAndReopen(options);

  const size_t kValueSize = 1 << 20;
@@ -3148,6 +3223,7 @@ TEST_P(DBCompactionTestWithParam, IntraL0Compaction) {
      ASSERT_OK(Put(Key(i + 1), value));
    }
    ASSERT_OK(Flush());
+    ASSERT_EQ(i + 1, TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
  }
  dbfull()->TEST_WaitForCompact();
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
@@ -3162,6 +3238,16 @@ TEST_P(DBCompactionTestWithParam, IntraL0Compaction) {
  for (int i = 0; i < 2; ++i) {
    ASSERT_GE(level_to_files[0][i].fd.file_size, 1 << 21);
  }
+
+  // The index/filter in the file produced by intra-L0 should not be pinned.
+  // That means clearing unref'd entries in block cache and re-accessing the
+  // file produced by intra-L0 should bump the index block miss count.
+  uint64_t prev_index_misses =
+      TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS);
+  table_options.block_cache->EraseUnRefEntries();
+  ASSERT_EQ("", Get(Key(0)));
+  ASSERT_EQ(prev_index_misses + 1,
+            TestGetTickerCount(options, BLOCK_CACHE_INDEX_MISS));
 }

 TEST_P(DBCompactionTestWithParam, IntraL0CompactionDoesNotObsoleteDeletions) {
@@ -4696,7 +4782,7 @@ TEST_P(CompactionPriTest, Test) {
  for (int i = 0; i < kNKeys; i++) {
    keys[i] = i;
  }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  RandomShuffle(std::begin(keys), std::end(keys), rnd.Next());

  for (int i = 0; i < kNKeys; i++) {
    ASSERT_OK(Put(Key(keys[i]), RandomString(&rnd, 102)));
@@ -4958,10 +5044,11 @@ TEST_P(DBCompactionTestWithParam, FixFileIngestionCompactionDeadlock) {

 TEST_F(DBCompactionTest, ConsistencyFailTest) {
  Options options = CurrentOptions();
+  options.force_consistency_checks = true;
  DestroyAndReopen(options);

  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
-      "VersionBuilder::CheckConsistency", [&](void* arg) {
+      "VersionBuilder::CheckConsistency0", [&](void* arg) {
        auto p =
            reinterpret_cast<std::pair<FileMetaData**, FileMetaData**>*>(arg);
        // just swap the two FileMetaData so that we hit error
@@ -4980,6 +5067,48 @@ TEST_F(DBCompactionTest, ConsistencyFailTest) {

  ASSERT_NOK(Put("foo", "bar"));
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
+TEST_F(DBCompactionTest, ConsistencyFailTest2) {
+  Options options = CurrentOptions();
+  options.force_consistency_checks = true;
+  options.target_file_size_base = 1000;
+  options.level0_file_num_compaction_trigger = 2;
+  BlockBasedTableOptions bbto;
+  bbto.block_size = 400;  // small block size
+  options.table_factory.reset(new BlockBasedTableFactory(bbto));
+  DestroyAndReopen(options);
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "VersionBuilder::CheckConsistency1", [&](void* arg) {
+        auto p =
+            reinterpret_cast<std::pair<FileMetaData**, FileMetaData**>*>(arg);
+        // just swap the two FileMetaData so that we hit error
+        // in CheckConsistency funcion
+        FileMetaData* temp = *(p->first);
+        *(p->first) = *(p->second);
+        *(p->second) = temp;
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  Random rnd(301);
+  std::string value = RandomString(&rnd, 1000);
+
+  ASSERT_OK(Put("foo1", value));
+  ASSERT_OK(Put("z", ""));
+  Flush();
+  ASSERT_OK(Put("foo2", value));
+  ASSERT_OK(Put("z", ""));
+  Flush();
+
+  // This probably returns non-OK, but we rely on the next Put()
+  // to determine the DB is frozen.
+  dbfull()->TEST_WaitForCompact();
+  ASSERT_NOK(Put("foo", "bar"));
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
 }

 void IngestOneKeyValue(DBImpl* db, const std::string& key,
@@ -5151,31 +5280,6 @@ TEST_P(DBCompactionTestWithParam,
  }
 }

-TEST_F(DBCompactionTest, FifoCompactionGetFileCreationTime) {
-  MockEnv mock_env(env_);
-  do {
-    Options options = CurrentOptions();
-    options.table_factory.reset(new BlockBasedTableFactory());
-    options.env = &mock_env;
-    options.ttl = static_cast<uint64_t>(24) * 3600;
-    options.compaction_style = kCompactionStyleFIFO;
-    constexpr size_t kNumFiles = 24;
-    options.max_open_files = 20;
-    constexpr size_t kNumKeysPerFile = 10;
-    DestroyAndReopen(options);
-    for (size_t i = 0; i < kNumFiles; ++i) {
-      for (size_t j = 0; j < kNumKeysPerFile; ++j) {
-        ASSERT_OK(Put(std::to_string(j), "value_" + std::to_string(i)));
-      }
-      ASSERT_OK(Flush());
-    }
-    mock_env.FakeSleepForMicroseconds(
-        static_cast<uint64_t>(1000 * 1000 * (1 + options.ttl)));
-    ASSERT_OK(Put("foo", "value"));
-    ASSERT_OK(Flush());
-  } while (ChangeOptions());
-}
-
 #endif // !defined(ROCKSDB_LITE)
 }  // namespace ROCKSDB_NAMESPACE

@@ -50,7 +50,7 @@ TEST_F(DBTestDynamicLevel, DynamicLevelMaxBytesBase) {
      keys[i] = i;
    }
    if (ordered_insert == 0) {
-      std::random_shuffle(std::begin(keys), std::end(keys));
+      RandomShuffle(std::begin(keys), std::end(keys), rnd.Next());
    }
    for (int max_background_compactions = 1; max_background_compactions < 4;
         max_background_compactions += 2) {
@@ -23,57 +23,6 @@

 namespace ROCKSDB_NAMESPACE {

-Status DBImpl::DisableFileDeletions() {
-  InstrumentedMutexLock l(&mutex_);
-  ++disable_delete_obsolete_files_;
-  if (disable_delete_obsolete_files_ == 1) {
-    ROCKS_LOG_INFO(immutable_db_options_.info_log, "File Deletions Disabled");
-  } else {
-    ROCKS_LOG_WARN(immutable_db_options_.info_log,
-                   "File Deletions Disabled, but already disabled. Counter: %d",
-                   disable_delete_obsolete_files_);
-  }
-  return Status::OK();
-}
-
-Status DBImpl::EnableFileDeletions(bool force) {
-  // Job id == 0 means that this is not our background process, but rather
-  // user thread
-  JobContext job_context(0);
-  bool file_deletion_enabled = false;
-  {
-    InstrumentedMutexLock l(&mutex_);
-    if (force) {
-      // if force, we need to enable file deletions right away
-      disable_delete_obsolete_files_ = 0;
-    } else if (disable_delete_obsolete_files_ > 0) {
-      --disable_delete_obsolete_files_;
-    }
-    if (disable_delete_obsolete_files_ == 0)  {
-      file_deletion_enabled = true;
-      FindObsoleteFiles(&job_context, true);
-      bg_cv_.SignalAll();
-    }
-  }
-  if (file_deletion_enabled) {
-    ROCKS_LOG_INFO(immutable_db_options_.info_log, "File Deletions Enabled");
-    if (job_context.HaveSomethingToDelete()) {
-      PurgeObsoleteFiles(job_context);
-    }
-  } else {
-    ROCKS_LOG_WARN(immutable_db_options_.info_log,
-                   "File Deletions Enable, but not really enabled. Counter: %d",
-                   disable_delete_obsolete_files_);
-  }
-  job_context.Clean();
-  LogFlush(immutable_db_options_.info_log);
-  return Status::OK();
-}
-
-int DBImpl::IsFileDeletionsEnabled() const {
-  return !disable_delete_obsolete_files_;
-}
-
 Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
                            uint64_t* manifest_file_size,
                            bool flush_memtable) {
@@ -90,6 +39,9 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
      mutex_.Unlock();
      status = AtomicFlushMemTables(cfds, FlushOptions(),
                                    FlushReason::kGetLiveFiles);
+      if (status.IsColumnFamilyDropped()) {
+        status = Status::OK();
+      }
      mutex_.Lock();
    } else {
      for (auto cfd : *versions_->GetColumnFamilySet()) {
@@ -103,8 +55,10 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
        TEST_SYNC_POINT("DBImpl::GetLiveFiles:2");
        mutex_.Lock();
        cfd->UnrefAndTryDelete();
-        if (!status.ok()) {
+        if (!status.ok() && !status.IsColumnFamilyDropped()) {
          break;
+        } else if (status.IsColumnFamilyDropped()) {
+          status = Status::OK();
        }
      }
    }
@@ -118,27 +72,33 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
    }
  }

-  // Make a set of all of the live *.sst files
-  std::vector<FileDescriptor> live;
+  // Make a set of all of the live table and blob files
+  std::vector<uint64_t> live_table_files;
+  std::vector<uint64_t> live_blob_files;
  for (auto cfd : *versions_->GetColumnFamilySet()) {
    if (cfd->IsDropped()) {
      continue;
    }
-    cfd->current()->AddLiveFiles(&live);
+    cfd->current()->AddLiveFiles(&live_table_files, &live_blob_files);
  }

  ret.clear();
-  ret.reserve(live.size() + 3);  // *.sst + CURRENT + MANIFEST + OPTIONS
+  ret.reserve(live_table_files.size() + live_blob_files.size() +
+              3);  // for CURRENT + MANIFEST + OPTIONS

  // create names of the live files. The names are not absolute
  // paths, instead they are relative to dbname_;
-  for (const auto& live_file : live) {
-    ret.push_back(MakeTableFileName("", live_file.GetNumber()));
+  for (const auto& table_file_number : live_table_files) {
+    ret.emplace_back(MakeTableFileName("", table_file_number));
  }

-  ret.push_back(CurrentFileName(""));
-  ret.push_back(DescriptorFileName("", versions_->manifest_file_number()));
-  ret.push_back(OptionsFileName("", versions_->options_file_number()));
+  for (const auto& blob_file_number : live_blob_files) {
+    ret.emplace_back(BlobFileName("", blob_file_number));
+  }
+
+  ret.emplace_back(CurrentFileName(""));
+  ret.emplace_back(DescriptorFileName("", versions_->manifest_file_number()));
+  ret.emplace_back(OptionsFileName("", versions_->options_file_number()));

  // find length of manifest file while holding the mutex lock
  *manifest_file_size = versions_->manifest_file_size();
@@ -499,13 +499,13 @@ TEST_P(DBAtomicFlushTest, AtomicFlushTriggeredByMemTableFull) {
  TEST_SYNC_POINT(
      "DBAtomicFlushTest::AtomicFlushTriggeredByMemTableFull:BeforeCheck");
  if (options.atomic_flush) {
-    for (size_t i = 0; i != num_cfs - 1; ++i) {
+    for (size_t i = 0; i + 1 != num_cfs; ++i) {
      auto cfh = static_cast<ColumnFamilyHandleImpl*>(handles_[i]);
      ASSERT_EQ(0, cfh->cfd()->imm()->NumNotFlushed());
      ASSERT_TRUE(cfh->cfd()->mem()->IsEmpty());
    }
  } else {
-    for (size_t i = 0; i != num_cfs - 1; ++i) {
+    for (size_t i = 0; i + 1 != num_cfs; ++i) {
      auto cfh = static_cast<ColumnFamilyHandleImpl*>(handles_[i]);
      ASSERT_EQ(0, cfh->cfd()->imm()->NumNotFlushed());
      ASSERT_FALSE(cfh->cfd()->mem()->IsEmpty());
@@ -150,7 +150,7 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
      own_info_log_(options.info_log == nullptr),
      initial_db_options_(SanitizeOptions(dbname, options)),
      env_(initial_db_options_.env),
-      fs_(initial_db_options_.file_system),
+      fs_(initial_db_options_.env->GetFileSystem()),
      immutable_db_options_(initial_db_options_),
      mutable_db_options_(initial_db_options_),
      stats_(immutable_db_options_.statistics.get()),
@@ -311,6 +311,39 @@ Status DBImpl::ResumeImpl() {
    s = bg_error;
  }

+  // Make sure the IO Status stored in version set is set to OK.
+  bool file_deletion_disabled = !IsFileDeletionsEnabled();
+  if (s.ok()) {
+    IOStatus io_s = versions_->io_status();
+    if (io_s.IsIOError()) {
+      // If resuming from IOError resulted from MANIFEST write, then assert
+      // that we must have already set the MANIFEST writer to nullptr during
+      // clean-up phase MANIFEST writing. We must have also disabled file
+      // deletions.
+      assert(!versions_->descriptor_log_);
+      assert(file_deletion_disabled);
+      // Since we are trying to recover from MANIFEST write error, we need to
+      // switch to a new MANIFEST anyway. The old MANIFEST can be corrupted.
+      // Therefore, force writing a dummy version edit because we do not know
+      // whether there are flush jobs with non-empty data to flush, triggering
+      // appends to MANIFEST.
+      VersionEdit edit;
+      auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(default_cf_handle_);
+      assert(cfh);
+      ColumnFamilyData* cfd = cfh->cfd();
+      const MutableCFOptions& cf_opts = *cfd->GetLatestMutableCFOptions();
+      s = versions_->LogAndApply(cfd, cf_opts, &edit, &mutex_,
+                                 directories_.GetDbDir());
+      if (!s.ok()) {
+        io_s = versions_->io_status();
+        if (!io_s.ok()) {
+          s = error_handler_.SetBGError(io_s,
+                                        BackgroundErrorReason::kManifestWrite);
+        }
+      }
+    }
+  }
+
  // We cannot guarantee consistency of the WAL. So force flush Memtables of
  // all the column families
  if (s.ok()) {
@@ -359,6 +392,13 @@ Status DBImpl::ResumeImpl() {
  job_context.Clean();

  if (s.ok()) {
+    assert(versions_->io_status().ok());
+    // If we reach here, we should re-enable file deletions if it was disabled
+    // during previous error handling.
+    if (file_deletion_disabled) {
+      // Always return ok
+      EnableFileDeletions(/*force=*/true);
+    }
    ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");
  }
  mutex_.Lock();
@@ -865,9 +905,7 @@ void DBImpl::DumpStats() {
 Status DBImpl::TablesRangeTombstoneSummary(ColumnFamilyHandle* column_family,
                                           int max_entries_to_print,
                                           std::string* out_str) {
-  auto* cfh =
-      static_cast_with_check<ColumnFamilyHandleImpl, ColumnFamilyHandle>(
-          column_family);
+  auto* cfh = static_cast_with_check<ColumnFamilyHandleImpl>(column_family);
  ColumnFamilyData* cfd = cfh->cfd();

  SuperVersion* super_version = cfd->GetReferencedSuperVersion(this);
@@ -1005,12 +1043,12 @@ Status DBImpl::SetDBOptions(
    }
    if (s.ok()) {
      const BGJobLimits current_bg_job_limits =
-          GetBGJobLimits(immutable_db_options_.max_background_flushes,
+          GetBGJobLimits(mutable_db_options_.max_background_flushes,
                         mutable_db_options_.max_background_compactions,
                         mutable_db_options_.max_background_jobs,
                         /* parallelize_compactions */ true);
      const BGJobLimits new_bg_job_limits = GetBGJobLimits(
-          immutable_db_options_.max_background_flushes,
+          new_options.max_background_flushes,
          new_options.max_background_compactions,
          new_options.max_background_jobs, /* parallelize_compactions */ true);

@@ -1146,25 +1184,25 @@ int DBImpl::FindMinimumEmptyLevelFitting(

 Status DBImpl::FlushWAL(bool sync) {
  if (manual_wal_flush_) {
-    Status s;
+    IOStatus io_s;
    {
      // We need to lock log_write_mutex_ since logs_ might change concurrently
      InstrumentedMutexLock wl(&log_write_mutex_);
      log::Writer* cur_log_writer = logs_.back().writer;
-      s = cur_log_writer->WriteBuffer();
+      io_s = cur_log_writer->WriteBuffer();
    }
-    if (!s.ok()) {
+    if (!io_s.ok()) {
      ROCKS_LOG_ERROR(immutable_db_options_.info_log, "WAL flush error %s",
-                      s.ToString().c_str());
+                      io_s.ToString().c_str());
      // In case there is a fs error we should set it globally to prevent the
      // future writes
-      WriteStatusCheck(s);
+      IOStatusCheck(io_s);
      // whether sync or not, we should abort the rest of function upon error
-      return s;
+      return std::move(io_s);
    }
    if (!sync) {
      ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "FlushWAL sync=false");
-      return s;
+      return std::move(io_s);
    }
  }
  if (!sync) {
@@ -1216,12 +1254,21 @@ Status DBImpl::SyncWAL() {
  TEST_SYNC_POINT("DBWALTest::SyncWALNotWaitWrite:1");
  RecordTick(stats_, WAL_FILE_SYNCED);
  Status status;
+  IOStatus io_s;
  for (log::Writer* log : logs_to_sync) {
-    status = log->file()->SyncWithoutFlush(immutable_db_options_.use_fsync);
-    if (!status.ok()) {
+    io_s = log->file()->SyncWithoutFlush(immutable_db_options_.use_fsync);
+    if (!io_s.ok()) {
+      status = io_s;
      break;
    }
  }
+  if (!io_s.ok()) {
+    ROCKS_LOG_ERROR(immutable_db_options_.info_log, "WAL Sync error %s",
+                    io_s.ToString().c_str());
+    // In case there is a fs error we should set it globally to prevent the
+    // future writes
+    IOStatusCheck(io_s);
+  }
  if (status.ok() && need_log_dir_sync) {
    status = directories_.GetWalDir()->Fsync(IOOptions(), nullptr);
  }
@@ -1248,7 +1295,7 @@ Status DBImpl::LockWAL() {
    // future writes
    WriteStatusCheck(status);
  }
-  return status;
+  return std::move(status);
 }

 Status DBImpl::UnlockWAL() {
@@ -1299,7 +1346,7 @@ bool DBImpl::SetPreserveDeletesSequenceNumber(SequenceNumber seqnum) {

 InternalIterator* DBImpl::NewInternalIterator(
    Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence,
-    ColumnFamilyHandle* column_family) {
+    ColumnFamilyHandle* column_family, bool allow_unprepared_value) {
  ColumnFamilyData* cfd;
  if (column_family == nullptr) {
    cfd = default_cf_handle_->cfd();
@@ -1313,7 +1360,7 @@ InternalIterator* DBImpl::NewInternalIterator(
  mutex_.Unlock();
  ReadOptions roptions;
  return NewInternalIterator(roptions, cfd, super_version, arena, range_del_agg,
-                             sequence);
+                             sequence, allow_unprepared_value);
 }

 void DBImpl::SchedulePurge() {
@@ -1436,7 +1483,8 @@ InternalIterator* DBImpl::NewInternalIterator(const ReadOptions& read_options,
                                              SuperVersion* super_version,
                                              Arena* arena,
                                              RangeDelAggregator* range_del_agg,
-                                              SequenceNumber sequence) {
+                                              SequenceNumber sequence,
+                                              bool allow_unprepared_value) {
  InternalIterator* internal_iter;
  assert(arena != nullptr);
  assert(range_del_agg != nullptr);
@@ -1468,7 +1516,8 @@ InternalIterator* DBImpl::NewInternalIterator(const ReadOptions& read_options,
    // Collect iterators for files in L0 - Ln
    if (read_options.read_tier != kMemtableTier) {
      super_version->current->AddIterators(read_options, file_options_,
-                                           &merge_iter_builder, range_del_agg);
+                                           &merge_iter_builder, range_del_agg,
+                                           allow_unprepared_value);
    }
    internal_iter = merge_iter_builder.Finish();
    IterState* cleanup =
@@ -1513,6 +1562,20 @@ Status DBImpl::GetImpl(const ReadOptions& read_options, const Slice& key,
                       GetImplOptions& get_impl_options) {
  assert(get_impl_options.value != nullptr ||
         get_impl_options.merge_operands != nullptr);
+
+#ifndef NDEBUG
+  assert(get_impl_options.column_family);
+  ColumnFamilyHandle* cf = get_impl_options.column_family;
+  const Comparator* const ucmp = cf->GetComparator();
+  assert(ucmp);
+  if (ucmp->timestamp_size() > 0) {
+    assert(read_options.timestamp);
+    assert(read_options.timestamp->size() == ucmp->timestamp_size());
+  } else {
+    assert(!read_options.timestamp);
+  }
+#endif  // NDEBUG
+
  PERF_CPU_TIMER_GUARD(get_cpu_nanos, env_);
  StopWatch sw(env_, stats_, DB_GET);
  PERF_TIMER_GUARD(get_snapshot_time);
@@ -1687,12 +1750,34 @@ std::vector<Status> DBImpl::MultiGet(
    const ReadOptions& read_options,
    const std::vector<ColumnFamilyHandle*>& column_family,
    const std::vector<Slice>& keys, std::vector<std::string>* values) {
+  return MultiGet(read_options, column_family, keys, values,
+                  /*timestamps=*/nullptr);
+}
+
+std::vector<Status> DBImpl::MultiGet(
+    const ReadOptions& read_options,
+    const std::vector<ColumnFamilyHandle*>& column_family,
+    const std::vector<Slice>& keys, std::vector<std::string>* values,
+    std::vector<std::string>* timestamps) {
  PERF_CPU_TIMER_GUARD(get_cpu_nanos, env_);
  StopWatch sw(env_, stats_, DB_MULTIGET);
  PERF_TIMER_GUARD(get_snapshot_time);

+#ifndef NDEBUG
+  for (const auto* cfh : column_family) {
+    assert(cfh);
+    const Comparator* const ucmp = cfh->GetComparator();
+    assert(ucmp);
+    if (ucmp->timestamp_size() > 0) {
+      assert(read_options.timestamp);
+      assert(ucmp->timestamp_size() == read_options.timestamp->size());
+    } else {
+      assert(!read_options.timestamp);
+    }
+  }
+#endif  // NDEBUG
+
  SequenceNumber consistent_seqnum;
-  ;

  std::unordered_map<uint32_t, MultiGetColumnFamilyData> multiget_cf_data(
      column_family.size());
@@ -1723,6 +1808,9 @@ std::vector<Status> DBImpl::MultiGet(
  size_t num_keys = keys.size();
  std::vector<Status> stat_list(num_keys);
  values->resize(num_keys);
+  if (timestamps) {
+    timestamps->resize(num_keys);
+  }

  // Keep track of bytes that we read for statistics-recording later
  uint64_t bytes_read = 0;
@@ -1733,13 +1821,17 @@ std::vector<Status> DBImpl::MultiGet(
  // s is both in/out. When in, s could either be OK or MergeInProgress.
  // merge_operands will contain the sequence of merges in the latter case.
  size_t num_found = 0;
-  for (size_t i = 0; i < num_keys; ++i) {
+  size_t keys_read;
+  uint64_t curr_value_size = 0;
+  for (keys_read = 0; keys_read < num_keys; ++keys_read) {
    merge_context.Clear();
-    Status& s = stat_list[i];
-    std::string* value = &(*values)[i];
+    Status& s = stat_list[keys_read];
+    std::string* value = &(*values)[keys_read];
+    std::string* timestamp = timestamps ? &(*timestamps)[keys_read] : nullptr;

-    LookupKey lkey(keys[i], consistent_seqnum);
-    auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family[i]);
+    LookupKey lkey(keys[keys_read], consistent_seqnum, read_options.timestamp);
+    auto cfh =
+        static_cast_with_check<ColumnFamilyHandleImpl>(column_family[keys_read]);
    SequenceNumber max_covering_tombstone_seq = 0;
    auto mgd_iter = multiget_cf_data.find(cfh->cfd()->GetID());
    assert(mgd_iter != multiget_cf_data.end());
@@ -1750,13 +1842,12 @@ std::vector<Status> DBImpl::MultiGet(
         has_unpersisted_data_.load(std::memory_order_relaxed));
    bool done = false;
    if (!skip_memtable) {
-      if (super_version->mem->Get(lkey, value, /*timestamp=*/nullptr, &s,
-                                  &merge_context, &max_covering_tombstone_seq,
-                                  read_options)) {
+      if (super_version->mem->Get(lkey, value, timestamp, &s, &merge_context,
+                                  &max_covering_tombstone_seq, read_options)) {
        done = true;
        RecordTick(stats_, MEMTABLE_HIT);
      } else if (super_version->imm->Get(
-                     lkey, value, nullptr, &s, &merge_context,
+                     lkey, value, timestamp, &s, &merge_context,
                     &max_covering_tombstone_seq, read_options)) {
        done = true;
        RecordTick(stats_, MEMTABLE_HIT);
@@ -1765,8 +1856,8 @@ std::vector<Status> DBImpl::MultiGet(
    if (!done) {
      PinnableSlice pinnable_val;
      PERF_TIMER_GUARD(get_from_output_files_time);
-      super_version->current->Get(read_options, lkey, &pinnable_val,
-                                  /*timestamp=*/nullptr, &s, &merge_context,
+      super_version->current->Get(read_options, lkey, &pinnable_val, timestamp,
+                                  &s, &merge_context,
                                  &max_covering_tombstone_seq);
      value->assign(pinnable_val.data(), pinnable_val.size());
      RecordTick(stats_, MEMTABLE_MISS);
@@ -1775,6 +1866,29 @@ std::vector<Status> DBImpl::MultiGet(
    if (s.ok()) {
      bytes_read += value->size();
      num_found++;
+      curr_value_size += value->size();
+      if (curr_value_size > read_options.value_size_soft_limit) {
+        while (++keys_read < num_keys) {
+          stat_list[keys_read] = Status::Aborted();
+        }
+        break;
+      }
+    }
+
+    if (read_options.deadline.count() &&
+        env_->NowMicros() >
+            static_cast<uint64_t>(read_options.deadline.count())) {
+      break;
+    }
+  }
+
+  if (keys_read < num_keys) {
+    // The only reason to break out of the loop is when the deadline is
+    // exceeded
+    assert(env_->NowMicros() >
+        static_cast<uint64_t>(read_options.deadline.count()));
+    for (++keys_read; keys_read < num_keys; ++keys_read) {
+      stat_list[keys_read] = Status::TimedOut();
    }
  }

@@ -1929,14 +2043,39 @@ void DBImpl::MultiGet(const ReadOptions& read_options, const size_t num_keys,
                      ColumnFamilyHandle** column_families, const Slice* keys,
                      PinnableSlice* values, Status* statuses,
                      const bool sorted_input) {
+  return MultiGet(read_options, num_keys, column_families, keys, values,
+                  /*timestamps=*/nullptr, statuses, sorted_input);
+}
+
+void DBImpl::MultiGet(const ReadOptions& read_options, const size_t num_keys,
+                      ColumnFamilyHandle** column_families, const Slice* keys,
+                      PinnableSlice* values, std::string* timestamps,
+                      Status* statuses, const bool sorted_input) {
  if (num_keys == 0) {
    return;
  }
+
+#ifndef NDEBUG
+  for (size_t i = 0; i < num_keys; ++i) {
+    ColumnFamilyHandle* cfh = column_families[i];
+    assert(cfh);
+    const Comparator* const ucmp = cfh->GetComparator();
+    assert(ucmp);
+    if (ucmp->timestamp_size() > 0) {
+      assert(read_options.timestamp);
+      assert(read_options.timestamp->size() == ucmp->timestamp_size());
+    } else {
+      assert(!read_options.timestamp);
+    }
+  }
+#endif  // NDEBUG
+
  autovector<KeyContext, MultiGetContext::MAX_BATCH_SIZE> key_context;
  autovector<KeyContext*, MultiGetContext::MAX_BATCH_SIZE> sorted_keys;
  sorted_keys.resize(num_keys);
  for (size_t i = 0; i < num_keys; ++i) {
    key_context.emplace_back(column_families[i], keys[i], &values[i],
+                             timestamps ? &timestamps[i] : nullptr,
                             &statuses[i]);
  }
  for (size_t i = 0; i < num_keys; ++i) {
@@ -1977,14 +2116,31 @@ void DBImpl::MultiGet(const ReadOptions& read_options, const size_t num_keys,
      read_options, nullptr, iter_deref_lambda, &multiget_cf_data,
      &consistent_seqnum);

-  for (auto cf_iter = multiget_cf_data.begin();
-       cf_iter != multiget_cf_data.end(); ++cf_iter) {
-    MultiGetImpl(read_options, cf_iter->start, cf_iter->num_keys, &sorted_keys,
-                 cf_iter->super_version, consistent_seqnum, nullptr, nullptr);
+  Status s;
+  auto cf_iter = multiget_cf_data.begin();
+  for (; cf_iter != multiget_cf_data.end(); ++cf_iter) {
+    s = MultiGetImpl(read_options, cf_iter->start, cf_iter->num_keys,
+                     &sorted_keys, cf_iter->super_version, consistent_seqnum,
+                     nullptr, nullptr);
+    if (!s.ok()) {
+      break;
+    }
+  }
+  if (!s.ok()) {
+    assert(s.IsTimedOut() || s.IsAborted());
+    for (++cf_iter; cf_iter != multiget_cf_data.end(); ++cf_iter) {
+      for (size_t i = cf_iter->start; i < cf_iter->start + cf_iter->num_keys;
+           ++i) {
+        *sorted_keys[i]->s = s;
+      }
+    }
+  }
+
+  for (const auto& iter : multiget_cf_data) {
    if (!unref_only) {
-      ReturnAndCleanupSuperVersion(cf_iter->cfd, cf_iter->super_version);
+      ReturnAndCleanupSuperVersion(iter.cfd, iter.super_version);
    } else {
-      cf_iter->cfd->GetSuperVersion()->Unref();
+      iter.cfd->GetSuperVersion()->Unref();
    }
  }
 }
@@ -2007,7 +2163,8 @@ struct CompareKeyContext {
    }

    // Both keys are from the same column family
-    int cmp = comparator->Compare(*(lhs->key), *(rhs->key));
+    int cmp = comparator->CompareWithoutTimestamp(
+        *(lhs->key), /*a_has_ts=*/false, *(rhs->key), /*b_has_ts=*/false);
    if (cmp < 0) {
      return true;
    }
@@ -2039,7 +2196,8 @@ void DBImpl::PrepareMultiGetKeys(
        }

        // Both keys are from the same column family
-        int cmp = comparator->Compare(*(lhs->key), *(rhs->key));
+        int cmp = comparator->CompareWithoutTimestamp(
+            *(lhs->key), /*a_has_ts=*/false, *(rhs->key), /*b_has_ts=*/false);
        assert(cmp <= 0);
      }
      index++;
@@ -2057,11 +2215,22 @@ void DBImpl::MultiGet(const ReadOptions& read_options,
                      ColumnFamilyHandle* column_family, const size_t num_keys,
                      const Slice* keys, PinnableSlice* values,
                      Status* statuses, const bool sorted_input) {
+  return MultiGet(read_options, column_family, num_keys, keys, values,
+                  /*timestamp=*/nullptr, statuses, sorted_input);
+}
+
+void DBImpl::MultiGet(const ReadOptions& read_options,
+                      ColumnFamilyHandle* column_family, const size_t num_keys,
+                      const Slice* keys, PinnableSlice* values,
+                      std::string* timestamps, Status* statuses,
+                      const bool sorted_input) {
  autovector<KeyContext, MultiGetContext::MAX_BATCH_SIZE> key_context;
  autovector<KeyContext*, MultiGetContext::MAX_BATCH_SIZE> sorted_keys;
  sorted_keys.resize(num_keys);
  for (size_t i = 0; i < num_keys; ++i) {
-    key_context.emplace_back(column_family, keys[i], &values[i], &statuses[i]);
+    key_context.emplace_back(column_family, keys[i], &values[i],
+                             timestamps ? &timestamps[i] : nullptr,
+                             &statuses[i]);
  }
  for (size_t i = 0; i < num_keys; ++i) {
    sorted_keys[i] = &key_context[i];
@@ -2114,14 +2283,24 @@ void DBImpl::MultiGetWithCallback(
    consistent_seqnum = callback->max_visible_seq();
  }

-  MultiGetImpl(read_options, 0, num_keys, sorted_keys,
-               multiget_cf_data[0].super_version, consistent_seqnum, nullptr,
-               nullptr);
+  Status s = MultiGetImpl(read_options, 0, num_keys, sorted_keys,
+                          multiget_cf_data[0].super_version, consistent_seqnum,
+                          nullptr, nullptr);
+  assert(s.ok() || s.IsTimedOut() || s.IsAborted());
  ReturnAndCleanupSuperVersion(multiget_cf_data[0].cfd,
                               multiget_cf_data[0].super_version);
 }

-void DBImpl::MultiGetImpl(
+// The actual implementation of batched MultiGet. Parameters -
+// start_key - Index in the sorted_keys vector to start processing from
+// num_keys - Number of keys to lookup, starting with sorted_keys[start_key]
+// sorted_keys - The entire batch of sorted keys for this CF
+//
+// The per key status is returned in the KeyContext structures pointed to by
+// sorted_keys. An overall Status is also returned, with the only possible
+// values being Status::OK() and Status::TimedOut(). The latter indicates
+// that the call exceeded read_options.deadline
+Status DBImpl::MultiGetImpl(
    const ReadOptions& read_options, size_t start_key, size_t num_keys,
    autovector<KeyContext*, MultiGetContext::MAX_BATCH_SIZE>* sorted_keys,
    SuperVersion* super_version, SequenceNumber snapshot,
@@ -2134,13 +2313,23 @@ void DBImpl::MultiGetImpl(
  // s is both in/out. When in, s could either be OK or MergeInProgress.
  // merge_operands will contain the sequence of merges in the latter case.
  size_t keys_left = num_keys;
+  Status s;
+  uint64_t curr_value_size = 0;
  while (keys_left) {
+    if (read_options.deadline.count() &&
+        env_->NowMicros() >
+            static_cast<uint64_t>(read_options.deadline.count())) {
+      s = Status::TimedOut();
+      break;
+    }
+
    size_t batch_size = (keys_left > MultiGetContext::MAX_BATCH_SIZE)
                            ? MultiGetContext::MAX_BATCH_SIZE
                            : keys_left;
    MultiGetContext ctx(sorted_keys, start_key + num_keys - keys_left,
-                        batch_size, snapshot);
+                        batch_size, snapshot, read_options);
    MultiGetRange range = ctx.GetMultiGetRange();
+    range.AddValueSize(curr_value_size);
    bool lookup_current = false;

    keys_left -= batch_size;
@@ -2171,19 +2360,32 @@ void DBImpl::MultiGetImpl(
      super_version->current->MultiGet(read_options, &range, callback,
                                       is_blob_index);
    }
+    curr_value_size = range.GetValueSize();
+    if (curr_value_size > read_options.value_size_soft_limit) {
+      s = Status::Aborted();
+      break;
+    }
  }

  // Post processing (decrement reference counts and record statistics)
  PERF_TIMER_GUARD(get_post_process_time);
  size_t num_found = 0;
  uint64_t bytes_read = 0;
-  for (size_t i = start_key; i < start_key + num_keys; ++i) {
+  for (size_t i = start_key; i < start_key + num_keys - keys_left; ++i) {
    KeyContext* key = (*sorted_keys)[i];
    if (key->s->ok()) {
      bytes_read += key->value->size();
      num_found++;
    }
  }
+  if (keys_left) {
+    assert(s.IsTimedOut() || s.IsAborted());
+    for (size_t i = start_key + num_keys - keys_left; i < start_key + num_keys;
+         ++i) {
+      KeyContext* key = (*sorted_keys)[i];
+      *key->s = s;
+    }
+  }

  RecordTick(stats_, NUMBER_MULTIGET_CALLS);
  RecordTick(stats_, NUMBER_MULTIGET_KEYS_READ, num_keys);
@@ -2192,6 +2394,8 @@ void DBImpl::MultiGetImpl(
  RecordInHistogram(stats_, BYTES_PER_MULTIGET, bytes_read);
  PERF_COUNTER_ADD(multiget_read_bytes, bytes_read);
  PERF_TIMER_STOP(get_post_process_time);
+
+  return s;
 }

 Status DBImpl::CreateColumnFamily(const ColumnFamilyOptions& cf_options,
@@ -2480,6 +2684,12 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    return NewErrorIterator(
        Status::NotSupported("Managed iterator is not supported anymore."));
  }
+  // We will eventually support deadline for iterators too, but safeguard
+  // for now
+  if (read_options.deadline != std::chrono::microseconds::zero()) {
+    return NewErrorIterator(
+        Status::NotSupported("ReadOptions deadline is not supported"));
+  }
  Iterator* result = nullptr;
  if (read_options.read_tier == kPersistedTier) {
    return NewErrorIterator(Status::NotSupported(
@@ -2495,7 +2705,8 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
        " guaranteed to be preserved, try larger iter_start_seqnum opt."));
  }
  auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
-  auto cfd = cfh->cfd();
+  ColumnFamilyData* cfd = cfh->cfd();
+  assert(cfd != nullptr);
  ReadCallback* read_callback = nullptr;  // No read callback provided.
  if (read_options.tailing) {
 #ifdef ROCKSDB_LITE
@@ -2504,7 +2715,8 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,

 #else
    SuperVersion* sv = cfd->GetReferencedSuperVersion(this);
-    auto iter = new ForwardIterator(this, read_options, cfd, sv);
+    auto iter = new ForwardIterator(this, read_options, cfd, sv,
+                                    /* allow_unprepared_value */ true);
    result = NewDBIterator(
        env_, read_options, *cfd->ioptions(), sv->mutable_cf_options,
        cfd->user_comparator(), iter, kMaxSequenceNumber,
@@ -2515,10 +2727,11 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    // Note: no need to consider the special case of
    // last_seq_same_as_publish_seq_==false since NewIterator is overridden in
    // WritePreparedTxnDB
-    auto snapshot = read_options.snapshot != nullptr
-                        ? read_options.snapshot->GetSequenceNumber()
-                        : versions_->LastSequence();
-    result = NewIteratorImpl(read_options, cfd, snapshot, read_callback);
+    result = NewIteratorImpl(read_options, cfd,
+                             (read_options.snapshot != nullptr)
+                                 ? read_options.snapshot->GetSequenceNumber()
+                                 : kMaxSequenceNumber,
+                             read_callback);
  }
  return result;
 }
@@ -2531,6 +2744,24 @@ ArenaWrappedDBIter* DBImpl::NewIteratorImpl(const ReadOptions& read_options,
                                            bool allow_refresh) {
  SuperVersion* sv = cfd->GetReferencedSuperVersion(this);

+  TEST_SYNC_POINT("DBImpl::NewIterator:1");
+  TEST_SYNC_POINT("DBImpl::NewIterator:2");
+
+  if (snapshot == kMaxSequenceNumber) {
+    // Note that the snapshot is assigned AFTER referencing the super
+    // version because otherwise a flush happening in between may compact away
+    // data for the snapshot, so the reader would see neither data that was be
+    // visible to the snapshot before compaction nor the newer data inserted
+    // afterwards.
+    // Note that the super version might not contain all the data available
+    // to this snapshot, but in that case it can see all the data in the
+    // super version, which is a valid consistent state after the user
+    // calls NewIterator().
+    snapshot = versions_->LastSequence();
+    TEST_SYNC_POINT("DBImpl::NewIterator:3");
+    TEST_SYNC_POINT("DBImpl::NewIterator:4");
+  }
+
  // Try to generate a DB iterator tree in continuous memory area to be
  // cache friendly. Here is an example of result:
  // +-------------------------------+
@@ -2581,7 +2812,8 @@ ArenaWrappedDBIter* DBImpl::NewIteratorImpl(const ReadOptions& read_options,

  InternalIterator* internal_iter =
      NewInternalIterator(read_options, cfd, sv, db_iter->GetArena(),
-                          db_iter->GetRangeDelAggregator(), snapshot);
+                          db_iter->GetRangeDelAggregator(), snapshot,
+                          /* allow_unprepared_value */ true);
  db_iter->SetIterUnderDBIter(internal_iter);

  return db_iter;
@@ -2609,7 +2841,8 @@ Status DBImpl::NewIterators(
    for (auto cfh : column_families) {
      auto cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
      SuperVersion* sv = cfd->GetReferencedSuperVersion(this);
-      auto iter = new ForwardIterator(this, read_options, cfd, sv);
+      auto iter = new ForwardIterator(this, read_options, cfd, sv,
+                                      /* allow_unprepared_value */ true);
      iterators->push_back(NewDBIterator(
          env_, read_options, *cfd->ioptions(), sv->mutable_cf_options,
          cfd->user_comparator(), iter, kMaxSequenceNumber,
@@ -3478,12 +3711,8 @@ Status DBImpl::Close() {
 Status DB::ListColumnFamilies(const DBOptions& db_options,
                              const std::string& name,
                              std::vector<std::string>* column_families) {
-  FileSystem* fs = db_options.file_system.get();
-  LegacyFileSystemWrapper legacy_fs(db_options.env);
-  if (!fs) {
-    fs = &legacy_fs;
-  }
-  return VersionSet::ListColumnFamilies(column_families, name, fs);
+  const std::shared_ptr<FileSystem>& fs = db_options.env->GetFileSystem();
+  return VersionSet::ListColumnFamilies(column_families, name, fs.get());
 }

 Snapshot::~Snapshot() {}
@@ -4006,7 +4235,8 @@ Status DBImpl::IngestExternalFiles(
        static_cast<ColumnFamilyHandleImpl*>(args[i].column_family)->cfd();
    SuperVersion* super_version = cfd->GetReferencedSuperVersion(this);
    exec_results[i].second = ingestion_jobs[i].Prepare(
-        args[i].external_files, start_file_number, super_version);
+        args[i].external_files, args[i].files_checksums,
+        args[i].files_checksum_func_names, start_file_number, super_version);
    exec_results[i].first = true;
    CleanupSuperVersion(super_version);
  }
@@ -4017,7 +4247,8 @@ Status DBImpl::IngestExternalFiles(
        static_cast<ColumnFamilyHandleImpl*>(args[0].column_family)->cfd();
    SuperVersion* super_version = cfd->GetReferencedSuperVersion(this);
    exec_results[0].second = ingestion_jobs[0].Prepare(
-        args[0].external_files, next_file_number, super_version);
+        args[0].external_files, args[0].files_checksums,
+        args[0].files_checksum_func_names, next_file_number, super_version);
    exec_results[0].first = true;
    CleanupSuperVersion(super_version);
  }
@@ -4193,6 +4424,14 @@ Status DBImpl::IngestExternalFiles(
 #endif  // !NDEBUG
        }
      }
+    } else if (versions_->io_status().IsIOError()) {
+      // Error while writing to MANIFEST.
+      // In fact, versions_->io_status() can also be the result of renaming
+      // CURRENT file. With current code, it's just difficult to tell. So just
+      // be pessimistic and try write to a new MANIFEST.
+      // TODO: distinguish between MANIFEST write and CURRENT renaming
+      const IOStatus& io_s = versions_->io_status();
+      error_handler_.SetBGError(io_s, BackgroundErrorReason::kManifestWrite);
    }

    // Resume writes to the DB
@@ -188,6 +188,11 @@ class DBImpl : public DB {
      const std::vector<ColumnFamilyHandle*>& column_family,
      const std::vector<Slice>& keys,
      std::vector<std::string>* values) override;
+  virtual std::vector<Status> MultiGet(
+      const ReadOptions& options,
+      const std::vector<ColumnFamilyHandle*>& column_family,
+      const std::vector<Slice>& keys, std::vector<std::string>* values,
+      std::vector<std::string>* timestamps) override;

  // This MultiGet is a batched version, which may be faster than calling Get
  // multiple times, especially if the keys have some spatial locality that
@@ -201,11 +206,22 @@ class DBImpl : public DB {
                        const size_t num_keys, const Slice* keys,
                        PinnableSlice* values, Status* statuses,
                        const bool sorted_input = false) override;
+  virtual void MultiGet(const ReadOptions& options,
+                        ColumnFamilyHandle* column_family,
+                        const size_t num_keys, const Slice* keys,
+                        PinnableSlice* values, std::string* timestamps,
+                        Status* statuses,
+                        const bool sorted_input = false) override;

  virtual void MultiGet(const ReadOptions& options, const size_t num_keys,
                        ColumnFamilyHandle** column_families, const Slice* keys,
                        PinnableSlice* values, Status* statuses,
                        const bool sorted_input = false) override;
+  virtual void MultiGet(const ReadOptions& options, const size_t num_keys,
+                        ColumnFamilyHandle** column_families, const Slice* keys,
+                        PinnableSlice* values, std::string* timestamps,
+                        Status* statuses,
+                        const bool sorted_input = false) override;

  virtual void MultiGetWithCallback(
      const ReadOptions& options, ColumnFamilyHandle* column_family,
@@ -340,6 +356,12 @@ class DBImpl : public DB {

  virtual Status Close() override;

+  virtual Status DisableFileDeletions() override;
+
+  virtual Status EnableFileDeletions(bool force) override;
+
+  virtual bool IsFileDeletionsEnabled() const;
+
  Status GetStatsHistory(
      uint64_t start_time, uint64_t end_time,
      std::unique_ptr<StatsHistoryIterator>* stats_iterator) override;
@@ -347,9 +369,6 @@ class DBImpl : public DB {
 #ifndef ROCKSDB_LITE
  using DB::ResetStats;
  virtual Status ResetStats() override;
-  virtual Status DisableFileDeletions() override;
-  virtual Status EnableFileDeletions(bool force) override;
-  virtual int IsFileDeletionsEnabled() const;
  // All the returned filenames start with "/"
  virtual Status GetLiveFiles(std::vector<std::string>&,
                              uint64_t* manifest_file_size,
@@ -461,6 +480,7 @@ class DBImpl : public DB {
  Status GetImpl(const ReadOptions& options, const Slice& key,
                 GetImplOptions& get_impl_options);

+  // If `snapshot` == kMaxSequenceNumber, set a recent one inside the file.
  ArenaWrappedDBIter* NewIteratorImpl(const ReadOptions& options,
                                      ColumnFamilyData* cfd,
                                      SequenceNumber snapshot,
@@ -565,9 +585,14 @@ class DBImpl : public DB {
  // Return an internal iterator over the current state of the database.
  // The keys of this iterator are internal keys (see format.h).
  // The returned iterator should be deleted when no longer needed.
+  // If allow_unprepared_value is true, the returned iterator may defer reading
+  // the value and so will require PrepareValue() to be called before value();
+  // allow_unprepared_value = false is convenient when this optimization is not
+  // useful, e.g. when reading the whole column family.
  InternalIterator* NewInternalIterator(
      Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence,
-      ColumnFamilyHandle* column_family = nullptr);
+      ColumnFamilyHandle* column_family = nullptr,
+      bool allow_unprepared_value = false);

  LogsWithPrepTracker* logs_with_prep_tracker() {
    return &logs_with_prep_tracker_;
@@ -693,7 +718,8 @@ class DBImpl : public DB {

  InternalIterator* NewInternalIterator(
      const ReadOptions&, ColumnFamilyData* cfd, SuperVersion* super_version,
-      Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence);
+      Arena* arena, RangeDelAggregator* range_del_agg, SequenceNumber sequence,
+      bool allow_unprepared_value);

  // hollow transactions shell used for recovery.
  // these will then be passed to TransactionDB so that
@@ -947,6 +973,12 @@ class DBImpl : public DB {
  void TEST_WaitForPersistStatsRun(std::function<void()> callback) const;
  bool TEST_IsPersistentStatsEnabled() const;
  size_t TEST_EstimateInMemoryStatsHistorySize() const;
+
+  VersionSet* TEST_GetVersionSet() const { return versions_.get(); }
+
+  const std::unordered_set<uint64_t>& TEST_GetFilesGrabbedForPurge() const {
+    return files_grabbed_for_purge_;
+  }
 #endif  // NDEBUG

 protected:
@@ -1124,6 +1156,15 @@ class DBImpl : public DB {

  virtual bool OwnTablesAndLogs() const { return true; }

+  // REQUIRES: db mutex held when calling this function, but the db mutex can
+  // be released and re-acquired. Db mutex will be held when the function
+  // returns.
+  // After best-efforts recovery, there may be SST files in db/cf paths that are
+  // not referenced in the MANIFEST. We delete these SST files. In the
+  // meantime, we find out the largest file number present in the paths, and
+  // bump up the version set's next_file_number_ to be 1 + largest_file_number.
+  Status FinishBestEffortsRecovery();
+
 private:
  friend class DB;
  friend class ErrorHandler;
@@ -1337,7 +1378,7 @@ class DBImpl : public DB {
  void ReleaseFileNumberFromPendingOutputs(
      std::unique_ptr<std::list<uint64_t>::iterator>& v);

-  Status SyncClosedLogs(JobContext* job_context);
+  IOStatus SyncClosedLogs(JobContext* job_context);

  // Flush the in-memory write buffer to storage.  Switches to a new
  // log-file/memtable and writes a new descriptor iff successful. Then
@@ -1474,21 +1515,25 @@ class DBImpl : public DB {
                         WriteBatch* tmp_batch, size_t* write_with_wal,
                         WriteBatch** to_be_cached_state);

-  Status WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
-                    uint64_t* log_used, uint64_t* log_size);
+  IOStatus WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
+                      uint64_t* log_used, uint64_t* log_size);

-  Status WriteToWAL(const WriteThread::WriteGroup& write_group,
-                    log::Writer* log_writer, uint64_t* log_used,
-                    bool need_log_sync, bool need_log_dir_sync,
-                    SequenceNumber sequence);
+  IOStatus WriteToWAL(const WriteThread::WriteGroup& write_group,
+                      log::Writer* log_writer, uint64_t* log_used,
+                      bool need_log_sync, bool need_log_dir_sync,
+                      SequenceNumber sequence);

-  Status ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
-                              uint64_t* log_used, SequenceNumber* last_sequence,
-                              size_t seq_inc);
+  IOStatus ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
+                                uint64_t* log_used,
+                                SequenceNumber* last_sequence, size_t seq_inc);

  // Used by WriteImpl to update bg_error_ if paranoid check is enabled.
  void WriteStatusCheck(const Status& status);

+  // Used by WriteImpl to update bg_error_ when IO error happens, e.g., write
+  // WAL, sync WAL fails, if paranoid check is enabled.
+  void IOStatusCheck(const IOStatus& status);
+
  // Used by WriteImpl to update bg_error_ in case of memtable insert error.
  void MemTableInsertStatusCheck(const Status& memtable_insert_status);

@@ -1732,12 +1777,14 @@ class DBImpl : public DB {
  // to have acquired the SuperVersion and pass in a snapshot sequence number
  // in order to construct the LookupKeys. The start_key and num_keys specify
  // the range of keys in the sorted_keys vector for a single column family.
-  void MultiGetImpl(
+  Status MultiGetImpl(
      const ReadOptions& read_options, size_t start_key, size_t num_keys,
      autovector<KeyContext*, MultiGetContext::MAX_BATCH_SIZE>* sorted_keys,
      SuperVersion* sv, SequenceNumber snap_seqnum, ReadCallback* callback,
      bool* is_blob_index);

+  Status DisableFileDeletionsWithLock();
+
  // table_cache_ provides its own synchronization
  std::shared_ptr<Cache> table_cache_;

@@ -1900,7 +1947,7 @@ class DBImpl : public DB {
  std::unordered_map<uint64_t, PurgeFileInfo> purge_files_;

  // A vector to store the file numbers that have been assigned to certain
-  // JobContext. Current implementation tracks ssts only.
+  // JobContext. Current implementation tracks table and blob files only.
  std::unordered_set<uint64_t> files_grabbed_for_purge_;

  // A queue to store log writers to close
@@ -79,7 +79,7 @@ bool DBImpl::RequestCompactionToken(ColumnFamilyData* cfd, bool force,
  return false;
 }

-Status DBImpl::SyncClosedLogs(JobContext* job_context) {
+IOStatus DBImpl::SyncClosedLogs(JobContext* job_context) {
  TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Start");
  mutex_.AssertHeld();
  autovector<log::Writer*, 1> logs_to_sync;
@@ -96,7 +96,7 @@ Status DBImpl::SyncClosedLogs(JobContext* job_context) {
    logs_to_sync.push_back(log.writer);
  }

-  Status s;
+  IOStatus io_s;
  if (!logs_to_sync.empty()) {
    mutex_.Unlock();

@@ -104,34 +104,34 @@ Status DBImpl::SyncClosedLogs(JobContext* job_context) {
      ROCKS_LOG_INFO(immutable_db_options_.info_log,
                     "[JOB %d] Syncing log #%" PRIu64, job_context->job_id,
                     log->get_log_number());
-      s = log->file()->Sync(immutable_db_options_.use_fsync);
-      if (!s.ok()) {
+      io_s = log->file()->Sync(immutable_db_options_.use_fsync);
+      if (!io_s.ok()) {
        break;
      }

      if (immutable_db_options_.recycle_log_file_num > 0) {
-        s = log->Close();
-        if (!s.ok()) {
+        io_s = log->Close();
+        if (!io_s.ok()) {
          break;
        }
      }
    }
-    if (s.ok()) {
-      s = directories_.GetWalDir()->Fsync(IOOptions(), nullptr);
+    if (io_s.ok()) {
+      io_s = directories_.GetWalDir()->Fsync(IOOptions(), nullptr);
    }

    mutex_.Lock();

    // "number <= current_log_number - 1" is equivalent to
    // "number < current_log_number".
-    MarkLogsSynced(current_log_number - 1, true, s);
-    if (!s.ok()) {
-      error_handler_.SetBGError(s, BackgroundErrorReason::kFlush);
+    MarkLogsSynced(current_log_number - 1, true, io_s);
+    if (!io_s.ok()) {
+      error_handler_.SetBGError(io_s, BackgroundErrorReason::kFlush);
      TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Failed");
-      return s;
+      return io_s;
    }
  }
-  return s;
+  return io_s;
 }

 Status DBImpl::FlushMemTableToOutputFile(
@@ -155,7 +155,6 @@ Status DBImpl::FlushMemTableToOutputFile(
      GetCompressionFlush(*cfd->ioptions(), mutable_cf_options), stats_,
      &event_logger_, mutable_cf_options.report_bg_io_stats,
      true /* sync_output_directory */, true /* write_manifest */, thread_pri);
-
  FileMetaData file_meta;

  TEST_SYNC_POINT("DBImpl::FlushMemTableToOutputFile:BeforePickMemtables");
@@ -168,6 +167,7 @@ Status DBImpl::FlushMemTableToOutputFile(
 #endif  // ROCKSDB_LITE

  Status s;
+  IOStatus io_s;
  if (logfile_number_ > 0 &&
      versions_->GetColumnFamilySet()->NumberOfColumnFamilies() > 1) {
    // If there are more than one column families, we need to make sure that
@@ -176,7 +176,8 @@ Status DBImpl::FlushMemTableToOutputFile(
    // flushed SST may contain data from write batches whose updates to
    // other column families are missing.
    // SyncClosedLogs() may unlock and re-lock the db_mutex.
-    s = SyncClosedLogs(job_context);
+    io_s = SyncClosedLogs(job_context);
+    s = io_s;
  } else {
    TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Skip");
  }
@@ -192,6 +193,7 @@ Status DBImpl::FlushMemTableToOutputFile(
  } else {
    flush_job.Cancel();
  }
+  io_s = flush_job.io_status();

  if (s.ok()) {
    InstallSuperVersionAndScheduleWork(cfd, superversion_context,
@@ -206,8 +208,21 @@ Status DBImpl::FlushMemTableToOutputFile(
  }

  if (!s.ok() && !s.IsShutdownInProgress() && !s.IsColumnFamilyDropped()) {
-    Status new_bg_error = s;
-    error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush);
+    if (!io_s.ok() && !io_s.IsShutdownInProgress() &&
+        !io_s.IsColumnFamilyDropped()) {
+      // Error while writing to MANIFEST.
+      // In fact, versions_->io_status() can also be the result of renaming
+      // CURRENT file. With current code, it's just difficult to tell. So just
+      // be pessimistic and try write to a new MANIFEST.
+      // TODO: distinguish between MANIFEST write and CURRENT renaming
+      auto err_reason = versions_->io_status().ok()
+                            ? BackgroundErrorReason::kFlush
+                            : BackgroundErrorReason::kManifestWrite;
+      error_handler_.SetBGError(io_s, err_reason);
+    } else {
+      Status new_bg_error = s;
+      error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush);
+    }
  }
  if (s.ok()) {
 #ifndef ROCKSDB_LITE
@@ -344,6 +359,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(

  std::vector<FileMetaData> file_meta(num_cfs);
  Status s;
+  IOStatus io_s;
  assert(num_cfs == static_cast<int>(jobs.size()));

 #ifndef ROCKSDB_LITE
@@ -358,15 +374,18 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
  if (logfile_number_ > 0) {
    // TODO (yanqin) investigate whether we should sync the closed logs for
    // single column family case.
-    s = SyncClosedLogs(job_context);
+    io_s = SyncClosedLogs(job_context);
+    s = io_s;
  }

  // exec_status stores the execution status of flush_jobs as
  // <bool /* executed */, Status /* status code */>
  autovector<std::pair<bool, Status>> exec_status;
+  autovector<IOStatus> io_status;
  for (int i = 0; i != num_cfs; ++i) {
    // Initially all jobs are not executed, with status OK.
    exec_status.emplace_back(false, Status::OK());
+    io_status.emplace_back(IOStatus::OK());
  }

  if (s.ok()) {
@@ -375,6 +394,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
      exec_status[i].second =
          jobs[i]->Run(&logs_with_prep_tracker_, &file_meta[i]);
      exec_status[i].first = true;
+      io_status[i] = jobs[i]->io_status();
    }
    if (num_cfs > 1) {
      TEST_SYNC_POINT(
@@ -387,6 +407,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
    exec_status[0].second =
        jobs[0]->Run(&logs_with_prep_tracker_, &file_meta[0]);
    exec_status[0].first = true;
+    io_status[0] = jobs[0]->io_status();

    Status error_status;
    for (const auto& e : exec_status) {
@@ -405,6 +426,20 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
    s = error_status.ok() ? s : error_status;
  }

+  if (io_s.ok()) {
+    IOStatus io_error = IOStatus::OK();
+    for (int i = 0; i != static_cast<int>(io_status.size()); i++) {
+      if (!io_status[i].ok() && !io_status[i].IsShutdownInProgress() &&
+          !io_status[i].IsColumnFamilyDropped()) {
+        io_error = io_status[i];
+      }
+    }
+    io_s = io_error;
+    if (s.ok() && !io_s.ok()) {
+      s = io_s;
+    }
+  }
+
  if (s.IsColumnFamilyDropped()) {
    s = Status::OK();
  }
@@ -543,9 +578,23 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
 #endif  // ROCKSDB_LITE
  }

-  if (!s.ok() && !s.IsShutdownInProgress()) {
-    Status new_bg_error = s;
-    error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush);
+  // Need to undo atomic flush if something went wrong, i.e. s is not OK and
+  // it is not because of CF drop.
+  if (!s.ok() && !s.IsColumnFamilyDropped()) {
+    if (!io_s.ok() && !io_s.IsColumnFamilyDropped()) {
+      // Error while writing to MANIFEST.
+      // In fact, versions_->io_status() can also be the result of renaming
+      // CURRENT file. With current code, it's just difficult to tell. So just
+      // be pessimistic and try write to a new MANIFEST.
+      // TODO: distinguish between MANIFEST write and CURRENT renaming
+      auto err_reason = versions_->io_status().ok()
+                            ? BackgroundErrorReason::kFlush
+                            : BackgroundErrorReason::kManifestWrite;
+      error_handler_.SetBGError(io_s, err_reason);
+    } else {
+      Status new_bg_error = s;
+      error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush);
+    }
  }

  return s;
@@ -1510,7 +1559,12 @@ Status DBImpl::RunManualCompaction(
      }
      manual.incomplete = false;
      bg_compaction_scheduled_++;
-      env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
+      Env::Priority thread_pool_pri = Env::Priority::LOW;
+      if (compaction->bottommost_level() &&
+          env_->GetBackgroundThreads(Env::Priority::BOTTOM) > 0) {
+        thread_pool_pri = Env::Priority::BOTTOM;
+      }
+      env_->Schedule(&DBImpl::BGWorkCompaction, ca, thread_pool_pri, this,
                     &DBImpl::UnscheduleCompactionCallback);
      scheduled = true;
    }
@@ -1868,7 +1922,7 @@ Status DBImpl::WaitForFlushMemTables(
      }
    }
    if (1 == num_dropped && 1 == num) {
-      return Status::InvalidArgument("Cannot flush a dropped CF");
+      return Status::ColumnFamilyDropped();
    }
    // Column families involved in this flush request have either been dropped
    // or finished flush. Then it's time to finish waiting.
@@ -1992,7 +2046,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {

 DBImpl::BGJobLimits DBImpl::GetBGJobLimits() const {
  mutex_.AssertHeld();
-  return GetBGJobLimits(immutable_db_options_.max_background_flushes,
+  return GetBGJobLimits(mutable_db_options_.max_background_flushes,
                        mutable_db_options_.max_background_compactions,
                        mutable_db_options_.max_background_jobs,
                        write_controller_.NeedSpeedupCompaction());
@@ -2105,8 +2159,7 @@ void DBImpl::BGWorkFlush(void* arg) {

  IOSTATS_SET_THREAD_POOL_ID(fta.thread_pri_);
  TEST_SYNC_POINT("DBImpl::BGWorkFlush");
-  static_cast_with_check<DBImpl, DB>(fta.db_)->BackgroundCallFlush(
-      fta.thread_pri_);
+  static_cast_with_check<DBImpl>(fta.db_)->BackgroundCallFlush(fta.thread_pri_);
  TEST_SYNC_POINT("DBImpl::BGWorkFlush:done");
 }

@@ -2117,7 +2170,7 @@ void DBImpl::BGWorkCompaction(void* arg) {
  TEST_SYNC_POINT("DBImpl::BGWorkCompaction");
  auto prepicked_compaction =
      static_cast<PrepickedCompaction*>(ca.prepicked_compaction);
-  static_cast_with_check<DBImpl, DB>(ca.db)->BackgroundCallCompaction(
+  static_cast_with_check<DBImpl>(ca.db)->BackgroundCallCompaction(
      prepicked_compaction, Env::Priority::LOW);
  delete prepicked_compaction;
 }
@@ -2511,8 +2564,8 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                       "[%s] Manual compaction from level-%d from %s .. "
                       "%s; nothing to do\n",
                       m->cfd->GetName().c_str(), m->input_level,
-                       (m->begin ? m->begin->DebugString().c_str() : "(begin)"),
-                       (m->end ? m->end->DebugString().c_str() : "(end)"));
+                       (m->begin ? m->begin->DebugString(true).c_str() : "(begin)"),
+                       (m->end ? m->end->DebugString(true).c_str() : "(end)"));
    } else {
      // First check if we have enough room to do the compaction
      bool enough_room = EnoughRoomForCompaction(
@@ -2531,11 +2584,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
            "[%s] Manual compaction from level-%d to level-%d from %s .. "
            "%s; will stop at %s\n",
            m->cfd->GetName().c_str(), m->input_level, c->output_level(),
-            (m->begin ? m->begin->DebugString().c_str() : "(begin)"),
-            (m->end ? m->end->DebugString().c_str() : "(end)"),
+            (m->begin ? m->begin->DebugString(true).c_str() : "(begin)"),
+            (m->end ? m->end->DebugString(true).c_str() : "(end)"),
            ((m->done || m->manual_end == nullptr)
                 ? "(end)"
-                 : m->manual_end->DebugString().c_str()));
+                 : m->manual_end->DebugString(true).c_str()));
      }
    }
  } else if (!is_prepicked && !compaction_queue_.empty()) {
@@ -2628,6 +2681,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    }
  }

+  IOStatus io_s;
  if (!c) {
    // Nothing to do
    ROCKS_LOG_BUFFER(log_buffer, "Compaction nothing to do");
@@ -2652,6 +2706,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    status = versions_->LogAndApply(c->column_family_data(),
                                    *c->mutable_cf_options(), c->edit(),
                                    &mutex_, directories_.GetDbDir());
+    io_s = versions_->io_status();
    InstallSuperVersionAndScheduleWork(c->column_family_data(),
                                       &job_context->superversion_contexts[0],
                                       *c->mutable_cf_options());
@@ -2708,6 +2763,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    status = versions_->LogAndApply(c->column_family_data(),
                                    *c->mutable_cf_options(), c->edit(),
                                    &mutex_, directories_.GetDbDir());
+    io_s = versions_->io_status();
    // Use latest MutableCFOptions
    InstallSuperVersionAndScheduleWork(c->column_family_data(),
                                       &job_context->superversion_contexts[0],
@@ -2794,6 +2850,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    mutex_.Lock();

    status = compaction_job.Install(*c->mutable_cf_options());
+    io_s = compaction_job.io_status();
    if (status.ok()) {
      InstallSuperVersionAndScheduleWork(c->column_family_data(),
                                         &job_context->superversion_contexts[0],
@@ -2803,6 +2860,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:AfterCompaction",
                             c->column_family_data());
  }
+
+  if (status.ok() && !io_s.ok()) {
+    status = io_s;
+  }
+
  if (c != nullptr) {
    c->ReleaseCompactionFiles(status);
    *made_progress = true;
@@ -2828,7 +2890,19 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
  } else {
    ROCKS_LOG_WARN(immutable_db_options_.info_log, "Compaction error: %s",
                   status.ToString().c_str());
-    error_handler_.SetBGError(status, BackgroundErrorReason::kCompaction);
+    if (!io_s.ok()) {
+      // Error while writing to MANIFEST.
+      // In fact, versions_->io_status() can also be the result of renaming
+      // CURRENT file. With current code, it's just difficult to tell. So just
+      // be pessimistic and try write to a new MANIFEST.
+      // TODO: distinguish between MANIFEST write and CURRENT renaming
+      auto err_reason = versions_->io_status().ok()
+                            ? BackgroundErrorReason::kCompaction
+                            : BackgroundErrorReason::kManifestWrite;
+      error_handler_.SetBGError(io_s, err_reason);
+    } else {
+      error_handler_.SetBGError(status, BackgroundErrorReason::kCompaction);
+    }
    if (c != nullptr && !is_manual && !error_handler_.IsBGWorkStopped()) {
      // Put this cfd back in the compaction queue so we can retry after some
      // time
@@ -14,6 +14,7 @@
 #include "db/event_helpers.h"
 #include "db/memtable_list.h"
 #include "file/file_util.h"
+#include "file/filename.h"
 #include "file/sst_file_manager_impl.h"
 #include "util/autovector.h"

@@ -35,7 +36,63 @@ uint64_t DBImpl::MinObsoleteSstNumberToKeep() {
  return std::numeric_limits<uint64_t>::max();
 }

-// * Returns the list of live files in 'sst_live'
+Status DBImpl::DisableFileDeletions() {
+  InstrumentedMutexLock l(&mutex_);
+  return DisableFileDeletionsWithLock();
+}
+
+Status DBImpl::DisableFileDeletionsWithLock() {
+  mutex_.AssertHeld();
+  ++disable_delete_obsolete_files_;
+  if (disable_delete_obsolete_files_ == 1) {
+    ROCKS_LOG_INFO(immutable_db_options_.info_log, "File Deletions Disabled");
+  } else {
+    ROCKS_LOG_WARN(immutable_db_options_.info_log,
+                   "File Deletions Disabled, but already disabled. Counter: %d",
+                   disable_delete_obsolete_files_);
+  }
+  return Status::OK();
+}
+
+Status DBImpl::EnableFileDeletions(bool force) {
+  // Job id == 0 means that this is not our background process, but rather
+  // user thread
+  JobContext job_context(0);
+  bool file_deletion_enabled = false;
+  {
+    InstrumentedMutexLock l(&mutex_);
+    if (force) {
+      // if force, we need to enable file deletions right away
+      disable_delete_obsolete_files_ = 0;
+    } else if (disable_delete_obsolete_files_ > 0) {
+      --disable_delete_obsolete_files_;
+    }
+    if (disable_delete_obsolete_files_ == 0) {
+      file_deletion_enabled = true;
+      FindObsoleteFiles(&job_context, true);
+      bg_cv_.SignalAll();
+    }
+  }
+  if (file_deletion_enabled) {
+    ROCKS_LOG_INFO(immutable_db_options_.info_log, "File Deletions Enabled");
+    if (job_context.HaveSomethingToDelete()) {
+      PurgeObsoleteFiles(job_context);
+    }
+  } else {
+    ROCKS_LOG_WARN(immutable_db_options_.info_log,
+                   "File Deletions Enable, but not really enabled. Counter: %d",
+                   disable_delete_obsolete_files_);
+  }
+  job_context.Clean();
+  LogFlush(immutable_db_options_.info_log);
+  return Status::OK();
+}
+
+bool DBImpl::IsFileDeletionsEnabled() const {
+  return 0 == disable_delete_obsolete_files_;
+}
+
+// * Returns the list of live files in 'sst_live' and 'blob_live'.
 // If it's doing full scan:
 // * Returns the list of all files in the filesystem in
 // 'full_scan_candidate_files'.
@@ -76,26 +133,26 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
  // Since job_context->min_pending_output is set, until file scan finishes,
  // mutex_ cannot be released. Otherwise, we might see no min_pending_output
  // here but later find newer generated unfinalized files while scanning.
-  if (!pending_outputs_.empty()) {
-    job_context->min_pending_output = *pending_outputs_.begin();
-  } else {
-    // delete all of them
-    job_context->min_pending_output = std::numeric_limits<uint64_t>::max();
-  }
+  job_context->min_pending_output = MinObsoleteSstNumberToKeep();

  // Get obsolete files.  This function will also update the list of
  // pending files in VersionSet().
-  versions_->GetObsoleteFiles(&job_context->sst_delete_files,
-                              &job_context->manifest_delete_files,
-                              job_context->min_pending_output);
+  versions_->GetObsoleteFiles(
+      &job_context->sst_delete_files, &job_context->blob_delete_files,
+      &job_context->manifest_delete_files, job_context->min_pending_output);

-  // Mark the elements in job_context->sst_delete_files as grabbedForPurge
-  // so that other threads calling FindObsoleteFiles with full_scan=true
-  // will not add these files to candidate list for purge.
+  // Mark the elements in job_context->sst_delete_files and
+  // job_context->blob_delete_files as "grabbed for purge" so that other threads
+  // calling FindObsoleteFiles with full_scan=true will not add these files to
+  // candidate list for purge.
  for (const auto& sst_to_del : job_context->sst_delete_files) {
    MarkAsGrabbedForPurge(sst_to_del.metadata->fd.GetNumber());
  }

+  for (const auto& blob_file : job_context->blob_delete_files) {
+    MarkAsGrabbedForPurge(blob_file.GetBlobFileNumber());
+  }
+
  // store the current filenum, lognum, etc
  job_context->manifest_file_number = versions_->manifest_file_number();
  job_context->pending_manifest_file_number =
@@ -103,7 +160,7 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
  job_context->log_number = MinLogNumberToKeep();
  job_context->prev_log_number = versions_->prev_log_number();

-  versions_->AddLiveFiles(&job_context->sst_live);
+  versions_->AddLiveFiles(&job_context->sst_live, &job_context->blob_live);
  if (doing_the_full_scan) {
    InfoLogPrefix info_log_prefix(!immutable_db_options_.db_log_dir.empty(),
                                  dbname_);
@@ -256,8 +313,11 @@ bool CompareCandidateFile(const JobContext::CandidateFileInfo& first,
 void DBImpl::DeleteObsoleteFileImpl(int job_id, const std::string& fname,
                                    const std::string& path_to_sync,
                                    FileType type, uint64_t number) {
+  TEST_SYNC_POINT_CALLBACK("DBImpl::DeleteObsoleteFileImpl::BeforeDeletion",
+                           const_cast<std::string*>(&fname));
+
  Status file_deletion_status;
-  if (type == kTableFile || type == kLogFile) {
+  if (type == kTableFile || type == kBlobFile || type == kLogFile) {
    file_deletion_status =
        DeleteDBFile(&immutable_db_options_, fname, path_to_sync,
                     /*force_bg=*/false, /*force_fg=*/!wal_in_db_path_);
@@ -303,19 +363,19 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
  // FindObsoleteFiles() should've populated this so nonzero
  assert(state.manifest_file_number != 0);

-  // Now, convert live list to an unordered map, WITHOUT mutex held;
-  // set is slow.
-  std::unordered_map<uint64_t, const FileDescriptor*> sst_live_map;
-  for (const FileDescriptor& fd : state.sst_live) {
-    sst_live_map[fd.GetNumber()] = &fd;
-  }
+  // Now, convert lists to unordered sets, WITHOUT mutex held; set is slow.
+  std::unordered_set<uint64_t> sst_live_set(state.sst_live.begin(),
+                                            state.sst_live.end());
+  std::unordered_set<uint64_t> blob_live_set(state.blob_live.begin(),
+                                             state.blob_live.end());
  std::unordered_set<uint64_t> log_recycle_files_set(
      state.log_recycle_files.begin(), state.log_recycle_files.end());

  auto candidate_files = state.full_scan_candidate_files;
  candidate_files.reserve(
      candidate_files.size() + state.sst_delete_files.size() +
-      state.log_delete_files.size() + state.manifest_delete_files.size());
+      state.blob_delete_files.size() + state.log_delete_files.size() +
+      state.manifest_delete_files.size());
  // We may ignore the dbname when generating the file names.
  for (auto& file : state.sst_delete_files) {
    candidate_files.emplace_back(
@@ -326,6 +386,11 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
    file.DeleteMetadata();
  }

+  for (const auto& blob_file : state.blob_delete_files) {
+    candidate_files.emplace_back(BlobFileName(blob_file.GetBlobFileNumber()),
+                                 blob_file.GetPath());
+  }
+
  for (auto file_num : state.log_delete_files) {
    if (file_num > 0) {
      candidate_files.emplace_back(LogFileName(file_num),
@@ -412,12 +477,19 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
      case kTableFile:
        // If the second condition is not there, this makes
        // DontDeletePendingOutputs fail
-        keep = (sst_live_map.find(number) != sst_live_map.end()) ||
+        keep = (sst_live_set.find(number) != sst_live_set.end()) ||
               number >= state.min_pending_output;
        if (!keep) {
          files_to_del.insert(number);
        }
        break;
+      case kBlobFile:
+        keep = number >= state.min_pending_output ||
+               (blob_live_set.find(number) != blob_live_set.end());
+        if (!keep) {
+          files_to_del.insert(number);
+        }
+        break;
      case kTempFile:
        // Any temp files that are currently being written to must
        // be recorded in pending_outputs_, which is inserted into "live".
@@ -427,7 +499,8 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
        //
        // TODO(yhchiang): carefully modify the third condition to safely
        //                 remove the temp options files.
-        keep = (sst_live_map.find(number) != sst_live_map.end()) ||
+        keep = (sst_live_set.find(number) != sst_live_set.end()) ||
+               (blob_live_set.find(number) != blob_live_set.end()) ||
               (number == state.pending_manifest_file_number) ||
               (to_delete.find(kOptionsFileNamePrefix) != std::string::npos);
        break;
@@ -450,7 +523,6 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
      case kDBLockFile:
      case kIdentityFile:
      case kMetaDatabase:
-      case kBlobFile:
        keep = true;
        break;
    }
@@ -466,6 +538,9 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
      TableCache::Evict(table_cache_.get(), number);
      fname = MakeTableFileName(candidate_file.file_path, number);
      dir_to_sync = candidate_file.file_path;
+    } else if (type == kBlobFile) {
+      fname = BlobFileName(candidate_file.file_path, number);
+      dir_to_sync = candidate_file.file_path;
    } else {
      dir_to_sync =
          (type == kLogFile) ? immutable_db_options_.wal_dir : dbname_;
@@ -664,4 +739,72 @@ uint64_t PrecomputeMinLogNumberToKeep(
  return min_log_number_to_keep;
 }

+Status DBImpl::FinishBestEffortsRecovery() {
+  mutex_.AssertHeld();
+  std::vector<std::string> paths;
+  paths.push_back(NormalizePath(dbname_ + std::string(1, kFilePathSeparator)));
+  for (const auto& db_path : immutable_db_options_.db_paths) {
+    paths.push_back(
+        NormalizePath(db_path.path + std::string(1, kFilePathSeparator)));
+  }
+  for (const auto* cfd : *versions_->GetColumnFamilySet()) {
+    for (const auto& cf_path : cfd->ioptions()->cf_paths) {
+      paths.push_back(
+          NormalizePath(cf_path.path + std::string(1, kFilePathSeparator)));
+    }
+  }
+  // Dedup paths
+  std::sort(paths.begin(), paths.end());
+  paths.erase(std::unique(paths.begin(), paths.end()), paths.end());
+
+  uint64_t next_file_number = versions_->current_next_file_number();
+  uint64_t largest_file_number = next_file_number;
+  std::set<std::string> files_to_delete;
+  for (const auto& path : paths) {
+    std::vector<std::string> files;
+    env_->GetChildren(path, &files);
+    for (const auto& fname : files) {
+      uint64_t number = 0;
+      FileType type;
+      if (!ParseFileName(fname, &number, &type)) {
+        continue;
+      }
+      // path ends with '/' or '\\'
+      const std::string normalized_fpath = path + fname;
+      largest_file_number = std::max(largest_file_number, number);
+      if (type == kTableFile && number >= next_file_number &&
+          files_to_delete.find(normalized_fpath) == files_to_delete.end()) {
+        files_to_delete.insert(normalized_fpath);
+      }
+    }
+  }
+  if (largest_file_number > next_file_number) {
+    versions_->next_file_number_.store(largest_file_number + 1);
+  }
+
+  VersionEdit edit;
+  edit.SetNextFile(versions_->next_file_number_.load());
+  assert(versions_->GetColumnFamilySet());
+  ColumnFamilyData* default_cfd = versions_->GetColumnFamilySet()->GetDefault();
+  assert(default_cfd);
+  // Even if new_descriptor_log is false, we will still switch to a new
+  // MANIFEST and update CURRENT file, since this is in recovery.
+  Status s = versions_->LogAndApply(
+      default_cfd, *default_cfd->GetLatestMutableCFOptions(), &edit, &mutex_,
+      directories_.GetDbDir(), /*new_descriptor_log*/ false);
+  if (!s.ok()) {
+    return s;
+  }
+
+  mutex_.Unlock();
+  for (const auto& fname : files_to_delete) {
+    s = env_->DeleteFile(fname);
+    if (!s.ok()) {
+      break;
+    }
+  }
+  mutex_.Lock();
+  return s;
+}
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -35,16 +35,8 @@ Options SanitizeOptions(const std::string& dbname, const Options& src) {
 DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
  DBOptions result(src);

-  if (result.file_system == nullptr) {
-    if (result.env == Env::Default()) {
-      result.file_system = FileSystem::Default();
-    } else {
-      result.file_system.reset(new LegacyFileSystemWrapper(result.env));
-    }
-  } else {
-    if (result.env == nullptr) {
-      result.env = Env::Default();
-    }
+  if (result.env == nullptr) {
+    result.env = Env::Default();
  }

  // result.max_open_files means an "infinite" open files.
@@ -252,6 +244,12 @@ Status DBImpl::ValidateOptions(const DBOptions& db_options) {
        "atomic_flush is incompatible with enable_pipelined_write");
  }

+  // TODO remove this restriction
+  if (db_options.atomic_flush && db_options.best_efforts_recovery) {
+    return Status::InvalidArgument(
+        "atomic_flush is currently incompatible with best-efforts recovery");
+  }
+
  return Status::OK();
 }

@@ -294,7 +292,7 @@ Status DBImpl::NewDB() {
  }
  if (s.ok()) {
    // Make "CURRENT" file that points to the new manifest file.
-    s = SetCurrentFile(env_, dbname_, 1, directories_.GetDbDir());
+    s = SetCurrentFile(fs_.get(), dbname_, 1, directories_.GetDbDir());
  } else {
    fs_->DeleteFile(manifest, IOOptions(), nullptr);
  }
@@ -372,7 +370,30 @@ Status DBImpl::Recover(
    }

    std::string current_fname = CurrentFileName(dbname_);
-    s = env_->FileExists(current_fname);
+    // Path to any MANIFEST file in the db dir. It does not matter which one.
+    // Since best-efforts recovery ignores CURRENT file, existence of a
+    // MANIFEST indicates the recovery to recover existing db. If no MANIFEST
+    // can be found, a new db will be created.
+    std::string manifest_path;
+    if (!immutable_db_options_.best_efforts_recovery) {
+      s = env_->FileExists(current_fname);
+    } else {
+      s = Status::NotFound();
+      std::vector<std::string> files;
+      // No need to check return value
+      env_->GetChildren(dbname_, &files);
+      for (const std::string& file : files) {
+        uint64_t number = 0;
+        FileType type = kLogFile;  // initialize
+        if (ParseFileName(file, &number, &type) && type == kDescriptorFile) {
+          // Found MANIFEST (descriptor log), thus best-efforts recovery does
+          // not have to treat the db as empty.
+          s = Status::OK();
+          manifest_path = dbname_ + "/" + file;
+          break;
+        }
+      }
+    }
    if (s.IsNotFound()) {
      if (immutable_db_options_.create_if_missing) {
        s = NewDB();
@@ -400,14 +421,14 @@ Status DBImpl::Recover(
      FileOptions customized_fs(file_options_);
      customized_fs.use_direct_reads |=
          immutable_db_options_.use_direct_io_for_flush_and_compaction;
-      s = fs_->NewRandomAccessFile(current_fname, customized_fs, &idfile,
-                                   nullptr);
+      const std::string& fname =
+          manifest_path.empty() ? current_fname : manifest_path;
+      s = fs_->NewRandomAccessFile(fname, customized_fs, &idfile, nullptr);
      if (!s.ok()) {
        std::string error_str = s.ToString();
        // Check if unsupported Direct I/O is the root cause
        customized_fs.use_direct_reads = false;
-        s = fs_->NewRandomAccessFile(current_fname, customized_fs, &idfile,
-                                     nullptr);
+        s = fs_->NewRandomAccessFile(fname, customized_fs, &idfile, nullptr);
        if (s.ok()) {
          return Status::InvalidArgument(
              "Direct I/O is not supported by the specified DB.");
@@ -419,7 +440,20 @@ Status DBImpl::Recover(
    }
  }
  assert(db_id_.empty());
-  Status s = versions_->Recover(column_families, read_only, &db_id_);
+  Status s;
+  bool missing_table_file = false;
+  if (!immutable_db_options_.best_efforts_recovery) {
+    s = versions_->Recover(column_families, read_only, &db_id_);
+  } else {
+    s = versions_->TryRecover(column_families, read_only, &db_id_,
+                              &missing_table_file);
+    if (s.ok()) {
+      // TryRecover may delete previous column_family_set_.
+      column_family_memtables_.reset(
+          new ColumnFamilyMemTablesImpl(versions_->GetColumnFamilySet()));
+      s = FinishBestEffortsRecovery();
+    }
+  }
  if (!s.ok()) {
    return s;
  }
@@ -499,7 +533,9 @@ Status DBImpl::Recover(
    // attention to it in case we are recovering a database
    // produced by an older version of rocksdb.
    std::vector<std::string> filenames;
-    s = env_->GetChildren(immutable_db_options_.wal_dir, &filenames);
+    if (!immutable_db_options_.best_efforts_recovery) {
+      s = env_->GetChildren(immutable_db_options_.wal_dir, &filenames);
+    }
    if (s.IsNotFound()) {
      return Status::InvalidArgument("wal_dir not found",
                                     immutable_db_options_.wal_dir);
@@ -691,10 +727,10 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
    Status* status;  // nullptr if immutable_db_options_.paranoid_checks==false
    void Corruption(size_t bytes, const Status& s) override {
      ROCKS_LOG_WARN(info_log, "%s%s: dropping %d bytes; %s",
-                     (this->status == nullptr ? "(ignoring error) " : ""),
-                     fname, static_cast<int>(bytes), s.ToString().c_str());
-      if (this->status != nullptr && this->status->ok()) {
-        *this->status = s;
+                     (status == nullptr ? "(ignoring error) " : ""), fname,
+                     static_cast<int>(bytes), s.ToString().c_str());
+      if (status != nullptr && status->ok()) {
+        *status = s;
      }
    }
  };
@@ -817,6 +853,8 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
    Slice record;
    WriteBatch batch;

+    TEST_SYNC_POINT_CALLBACK("DBImpl::RecoverLogFiles:BeforeReadWal",
+                             /*arg=*/nullptr);
    while (!stop_replay_by_wal_filter &&
           reader.ReadRecord(&record, &scratch,
                             immutable_db_options_.wal_recovery_mode) &&
@@ -981,6 +1019,16 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
        status = Status::OK();
      } else if (immutable_db_options_.wal_recovery_mode ==
                 WALRecoveryMode::kPointInTimeRecovery) {
+        if (status.IsIOError()) {
+          ROCKS_LOG_ERROR(immutable_db_options_.info_log,
+                          "IOError during point-in-time reading log #%" PRIu64
+                          " seq #%" PRIu64
+                          ". %s. This likely mean loss of synced WAL, "
+                          "thus recovery fails.",
+                          log_number, *next_sequence,
+                          status.ToString().c_str());
+          return status;
+        }
        // We should ignore the error but not continue replaying
        status = Status::OK();
        stop_replay_for_corruption = true;
@@ -1229,6 +1277,7 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
      if (range_del_iter != nullptr) {
        range_del_iters.emplace_back(range_del_iter);
      }
+      IOStatus io_s;
      s = BuildTable(
          dbname_, env_, fs_.get(), *cfd->ioptions(), mutable_cf_options,
          file_options_for_compaction_, cfd->table_cache(), iter.get(),
@@ -1237,8 +1286,8 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
          snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker,
          GetCompressionFlush(*cfd->ioptions(), mutable_cf_options),
          mutable_cf_options.sample_for_compression,
-          cfd->ioptions()->compression_opts, paranoid_file_checks,
-          cfd->internal_stats(), TableFileCreationReason::kRecovery,
+          mutable_cf_options.compression_opts, paranoid_file_checks,
+          cfd->internal_stats(), TableFileCreationReason::kRecovery, &io_s,
          &event_logger_, job_id, Env::IO_HIGH, nullptr /* table_properties */,
          -1 /* level */, current_time, write_hint);
      LogFlush(immutable_db_options_.info_log);
@@ -1555,6 +1604,12 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
  auto sfm = static_cast<SstFileManagerImpl*>(
      impl->immutable_db_options_.sst_file_manager.get());
  if (s.ok() && sfm) {
+    // Set Statistics ptr for SstFileManager to dump the stats of
+    // DeleteScheduler.
+    sfm->SetStatisticsPtr(impl->immutable_db_options_.statistics);
+    ROCKS_LOG_INFO(impl->immutable_db_options_.info_log,
+                   "SstFileManager instance %p", sfm);
+
    // Notify SstFileManager about all sst files that already exist in
    // db_paths[0] and cf_paths[0] when the DB is opened.

@@ -87,7 +87,8 @@ Iterator* DBImplReadOnly::NewIterator(const ReadOptions& read_options,
      super_version->version_number, read_callback);
  auto internal_iter =
      NewInternalIterator(read_options, cfd, super_version, db_iter->GetArena(),
-                          db_iter->GetRangeDelAggregator(), read_seq);
+                          db_iter->GetRangeDelAggregator(), read_seq,
+                          /* allow_unprepared_value */ true);
  db_iter->SetIterUnderDBIter(internal_iter);
  return db_iter;
 }
@@ -118,7 +119,8 @@ Status DBImplReadOnly::NewIterators(
        sv->version_number, read_callback);
    auto* internal_iter =
        NewInternalIterator(read_options, cfd, sv, db_iter->GetArena(),
-                            db_iter->GetRangeDelAggregator(), read_seq);
+                            db_iter->GetRangeDelAggregator(), read_seq,
+                            /* allow_unprepared_value */ true);
    db_iter->SetIterUnderDBIter(internal_iter);
    iterators->push_back(db_iter);
  }
@@ -126,12 +128,38 @@ Status DBImplReadOnly::NewIterators(
  return Status::OK();
 }

+namespace {
+// Return OK if dbname exists in the file system
+// or create_if_missing is false
+Status OpenForReadOnlyCheckExistence(const DBOptions& db_options,
+                                     const std::string& dbname) {
+  Status s;
+  if (!db_options.create_if_missing) {
+    // Attempt to read "CURRENT" file
+    const std::shared_ptr<FileSystem>& fs = db_options.env->GetFileSystem();
+    std::string manifest_path;
+    uint64_t manifest_file_number;
+    s = VersionSet::GetCurrentManifestPath(dbname, fs.get(), &manifest_path,
+                                           &manifest_file_number);
+    if (!s.ok()) {
+      return Status::NotFound(CurrentFileName(dbname), "does not exist");
+    }
+  }
+  return s;
+}
+}  // namespace
+
 Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
                           DB** dbptr, bool /*error_if_log_file_exist*/) {
+  // If dbname does not exist in the file system, should not do anything
+  Status s = OpenForReadOnlyCheckExistence(options, dbname);
+  if (!s.ok()) {
+    return s;
+  }
+
  *dbptr = nullptr;

  // Try to first open DB as fully compacted DB
-  Status s;
  s = CompactedDBImpl::Open(options, dbname, dbptr);
  if (s.ok()) {
    return s;
@@ -144,7 +172,8 @@ Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
      ColumnFamilyDescriptor(kDefaultColumnFamilyName, cf_options));
  std::vector<ColumnFamilyHandle*> handles;

-  s = DB::OpenForReadOnly(db_options, dbname, column_families, &handles, dbptr);
+  s = DBImplReadOnly::OpenForReadOnlyWithoutCheck(
+      db_options, dbname, column_families, &handles, dbptr);
  if (s.ok()) {
    assert(handles.size() == 1);
    // i can delete the handle since DBImpl is always holding a
@@ -159,6 +188,22 @@ Status DB::OpenForReadOnly(
    const std::vector<ColumnFamilyDescriptor>& column_families,
    std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
    bool error_if_log_file_exist) {
+  // If dbname does not exist in the file system, should not do anything
+  Status s = OpenForReadOnlyCheckExistence(db_options, dbname);
+  if (!s.ok()) {
+    return s;
+  }
+
+  return DBImplReadOnly::OpenForReadOnlyWithoutCheck(
+      db_options, dbname, column_families, handles, dbptr,
+      error_if_log_file_exist);
+}
+
+Status DBImplReadOnly::OpenForReadOnlyWithoutCheck(
+    const DBOptions& db_options, const std::string& dbname,
+    const std::vector<ColumnFamilyDescriptor>& column_families,
+    std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
+    bool error_if_log_file_exist) {
  *dbptr = nullptr;
  handles->clear();

@@ -130,6 +130,15 @@ class DBImplReadOnly : public DBImpl {
  }

 private:
+  // A "helper" function for DB::OpenForReadOnly without column families
+  // to reduce unnecessary I/O
+  // It has the same functionality as DB::OpenForReadOnly with column families
+  // but does not check the existence of dbname in the file system
+  static Status OpenForReadOnlyWithoutCheck(
+      const DBOptions& db_options, const std::string& dbname,
+      const std::vector<ColumnFamilyDescriptor>& column_families,
+      std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
+      bool error_if_log_file_exist = false);
  friend class DB;
 };
 }  // namespace ROCKSDB_NAMESPACE
@@ -417,7 +417,8 @@ ArenaWrappedDBIter* DBImplSecondary::NewIteratorImpl(
      super_version->version_number, read_callback);
  auto internal_iter =
      NewInternalIterator(read_options, cfd, super_version, db_iter->GetArena(),
-                          db_iter->GetRangeDelAggregator(), snapshot);
+                          db_iter->GetRangeDelAggregator(), snapshot,
+                          /* allow_unprepared_value */ true);
  db_iter->SetIterUnderDBIter(internal_iter);
  return db_iter;
 }
@@ -101,6 +101,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
         disable_memtable);

  Status status;
+  IOStatus io_s;
  if (write_options.low_pri) {
    status = ThrottleLowPriWritesIfNeeded(write_options, my_batch);
    if (!status.ok()) {
@@ -322,21 +323,22 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    if (!two_write_queues_) {
      if (status.ok() && !write_options.disableWAL) {
        PERF_TIMER_GUARD(write_wal_time);
-        status = WriteToWAL(write_group, log_writer, log_used, need_log_sync,
-                            need_log_dir_sync, last_sequence + 1);
+        io_s = WriteToWAL(write_group, log_writer, log_used, need_log_sync,
+                          need_log_dir_sync, last_sequence + 1);
      }
    } else {
      if (status.ok() && !write_options.disableWAL) {
        PERF_TIMER_GUARD(write_wal_time);
        // LastAllocatedSequence is increased inside WriteToWAL under
        // wal_write_mutex_ to ensure ordered events in WAL
-        status = ConcurrentWriteToWAL(write_group, log_used, &last_sequence,
-                                      seq_inc);
+        io_s = ConcurrentWriteToWAL(write_group, log_used, &last_sequence,
+                                    seq_inc);
      } else {
        // Otherwise we inc seq number for memtable writes
        last_sequence = versions_->FetchAddLastAllocatedSequence(seq_inc);
      }
    }
+    status = io_s;
    assert(last_sequence != kMaxSequenceNumber);
    const SequenceNumber current_sequence = last_sequence + 1;
    last_sequence += seq_inc;
@@ -411,7 +413,11 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
  PERF_TIMER_START(write_pre_and_post_process_time);

  if (!w.CallbackFailed()) {
-    WriteStatusCheck(status);
+    if (!io_s.ok()) {
+      IOStatusCheck(io_s);
+    } else {
+      WriteStatusCheck(status);
+    }
  }

  if (need_log_sync) {
@@ -515,6 +521,7 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,

    PERF_TIMER_STOP(write_pre_and_post_process_time);

+    IOStatus io_s;
    if (w.status.ok() && !write_options.disableWAL) {
      PERF_TIMER_GUARD(write_wal_time);
      stats->AddDBStats(InternalStats::kIntStatsWriteDoneBySelf, 1);
@@ -524,12 +531,17 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
                          wal_write_group.size - 1);
        RecordTick(stats_, WRITE_DONE_BY_OTHER, wal_write_group.size - 1);
      }
-      w.status = WriteToWAL(wal_write_group, log_writer, log_used,
-                            need_log_sync, need_log_dir_sync, current_sequence);
+      io_s = WriteToWAL(wal_write_group, log_writer, log_used, need_log_sync,
+                        need_log_dir_sync, current_sequence);
+      w.status = io_s;
    }

    if (!w.CallbackFailed()) {
-      WriteStatusCheck(w.status);
+      if (!io_s.ok()) {
+        IOStatusCheck(io_s);
+      } else {
+        WriteStatusCheck(w.status);
+      }
    }

    if (need_log_sync) {
@@ -740,9 +752,10 @@ Status DBImpl::WriteImplWALOnly(
    }
    seq_inc = total_batch_cnt;
  }
+  IOStatus io_s;
  if (!write_options.disableWAL) {
-    status =
-        ConcurrentWriteToWAL(write_group, log_used, &last_sequence, seq_inc);
+    io_s = ConcurrentWriteToWAL(write_group, log_used, &last_sequence, seq_inc);
+    status = io_s;
  } else {
    // Otherwise we inc seq number to do solely the seq allocation
    last_sequence = versions_->FetchAddLastAllocatedSequence(seq_inc);
@@ -777,7 +790,11 @@ Status DBImpl::WriteImplWALOnly(
  PERF_TIMER_START(write_pre_and_post_process_time);

  if (!w.CallbackFailed()) {
-    WriteStatusCheck(status);
+    if (!io_s.ok()) {
+      IOStatusCheck(io_s);
+    } else {
+      WriteStatusCheck(status);
+    }
  }
  if (status.ok()) {
    size_t index = 0;
@@ -823,6 +840,17 @@ void DBImpl::WriteStatusCheck(const Status& status) {
  }
 }

+void DBImpl::IOStatusCheck(const IOStatus& io_status) {
+  // Is setting bg_error_ enough here?  This will at least stop
+  // compaction and fail any further writes.
+  if (immutable_db_options_.paranoid_checks && !io_status.ok() &&
+      !io_status.IsBusy() && !io_status.IsIncomplete()) {
+    mutex_.Lock();
+    error_handler_.SetBGError(io_status, BackgroundErrorReason::kWriteCallback);
+    mutex_.Unlock();
+  }
+}
+
 void DBImpl::MemTableInsertStatusCheck(const Status& status) {
  // A non-OK status here indicates that the state implied by the
  // WAL has diverged from the in-memory state.  This could be
@@ -961,9 +989,9 @@ WriteBatch* DBImpl::MergeBatch(const WriteThread::WriteGroup& write_group,

 // When two_write_queues_ is disabled, this function is called from the only
 // write thread. Otherwise this must be called holding log_write_mutex_.
-Status DBImpl::WriteToWAL(const WriteBatch& merged_batch,
-                          log::Writer* log_writer, uint64_t* log_used,
-                          uint64_t* log_size) {
+IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
+                            log::Writer* log_writer, uint64_t* log_used,
+                            uint64_t* log_size) {
  assert(log_size != nullptr);
  Slice log_entry = WriteBatchInternal::Contents(&merged_batch);
  *log_size = log_entry.size();
@@ -978,7 +1006,8 @@ Status DBImpl::WriteToWAL(const WriteBatch& merged_batch,
  if (UNLIKELY(needs_locking)) {
    log_write_mutex_.Lock();
  }
-  Status status = log_writer->AddRecord(log_entry);
+  IOStatus io_s = log_writer->AddRecord(log_entry);
+
  if (UNLIKELY(needs_locking)) {
    log_write_mutex_.Unlock();
  }
@@ -990,15 +1019,14 @@ Status DBImpl::WriteToWAL(const WriteBatch& merged_batch,
  // since alive_log_files_ might be modified concurrently
  alive_log_files_.back().AddSize(log_entry.size());
  log_empty_ = false;
-  return status;
+  return io_s;
 }

-Status DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
-                          log::Writer* log_writer, uint64_t* log_used,
-                          bool need_log_sync, bool need_log_dir_sync,
-                          SequenceNumber sequence) {
-  Status status;
-
+IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
+                            log::Writer* log_writer, uint64_t* log_used,
+                            bool need_log_sync, bool need_log_dir_sync,
+                            SequenceNumber sequence) {
+  IOStatus io_s;
  assert(!write_group.leader->disable_wal);
  // Same holds for all in the batch group
  size_t write_with_wal = 0;
@@ -1016,13 +1044,13 @@ Status DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
  WriteBatchInternal::SetSequence(merged_batch, sequence);

  uint64_t log_size;
-  status = WriteToWAL(*merged_batch, log_writer, log_used, &log_size);
+  io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size);
  if (to_be_cached_state) {
    cached_recoverable_state_ = *to_be_cached_state;
    cached_recoverable_state_empty_ = false;
  }

-  if (status.ok() && need_log_sync) {
+  if (io_s.ok() && need_log_sync) {
    StopWatch sw(env_, stats_, WAL_FILE_SYNC_MICROS);
    // It's safe to access logs_ with unlocked mutex_ here because:
    //  - we've set getting_synced=true for all logs,
@@ -1032,23 +1060,24 @@ Status DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
    //  - as long as other threads don't modify it, it's safe to read
    //    from std::deque from multiple threads concurrently.
    for (auto& log : logs_) {
-      status = log.writer->file()->Sync(immutable_db_options_.use_fsync);
-      if (!status.ok()) {
+      io_s = log.writer->file()->Sync(immutable_db_options_.use_fsync);
+      if (!io_s.ok()) {
        break;
      }
    }
-    if (status.ok() && need_log_dir_sync) {
+
+    if (io_s.ok() && need_log_dir_sync) {
      // We only sync WAL directory the first time WAL syncing is
      // requested, so that in case users never turn on WAL sync,
      // we can avoid the disk I/O in the write code path.
-      status = directories_.GetWalDir()->Fsync(IOOptions(), nullptr);
+      io_s = directories_.GetWalDir()->Fsync(IOOptions(), nullptr);
    }
  }

  if (merged_batch == &tmp_batch_) {
    tmp_batch_.Clear();
  }
-  if (status.ok()) {
+  if (io_s.ok()) {
    auto stats = default_cf_internal_stats_;
    if (need_log_sync) {
      stats->AddDBStats(InternalStats::kIntStatsWalFileSynced, 1);
@@ -1059,14 +1088,13 @@ Status DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
    stats->AddDBStats(InternalStats::kIntStatsWriteWithWal, write_with_wal);
    RecordTick(stats_, WRITE_WITH_WAL, write_with_wal);
  }
-  return status;
+  return io_s;
 }

-Status DBImpl::ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
-                                    uint64_t* log_used,
-                                    SequenceNumber* last_sequence,
-                                    size_t seq_inc) {
-  Status status;
+IOStatus DBImpl::ConcurrentWriteToWAL(
+    const WriteThread::WriteGroup& write_group, uint64_t* log_used,
+    SequenceNumber* last_sequence, size_t seq_inc) {
+  IOStatus io_s;

  assert(!write_group.leader->disable_wal);
  // Same holds for all in the batch group
@@ -1092,14 +1120,14 @@ Status DBImpl::ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,

  log::Writer* log_writer = logs_.back().writer;
  uint64_t log_size;
-  status = WriteToWAL(*merged_batch, log_writer, log_used, &log_size);
+  io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size);
  if (to_be_cached_state) {
    cached_recoverable_state_ = *to_be_cached_state;
    cached_recoverable_state_empty_ = false;
  }
  log_write_mutex_.Unlock();

-  if (status.ok()) {
+  if (io_s.ok()) {
    const bool concurrent = true;
    auto stats = default_cf_internal_stats_;
    stats->AddDBStats(InternalStats::kIntStatsWalFileBytes, log_size,
@@ -1109,7 +1137,7 @@ Status DBImpl::ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
                      concurrent);
    RecordTick(stats_, WRITE_WITH_WAL, write_with_wal);
  }
-  return status;
+  return io_s;
 }

 Status DBImpl::WriteRecoverableState() {
@@ -1792,6 +1820,8 @@ Status DB::Put(const WriteOptions& opt, ColumnFamilyHandle* column_family,
  const Slice* ts = opt.timestamp;
  assert(nullptr != ts);
  size_t ts_sz = ts->size();
+  assert(column_family->GetComparator());
+  assert(ts_sz == column_family->GetComparator()->timestamp_size());
  WriteBatch batch(key.size() + ts_sz + value.size() + 24, /*max_bytes=*/0,
                   ts_sz);
  Status s = batch.Put(column_family, key, value);
@@ -1807,8 +1837,30 @@ Status DB::Put(const WriteOptions& opt, ColumnFamilyHandle* column_family,

 Status DB::Delete(const WriteOptions& opt, ColumnFamilyHandle* column_family,
                  const Slice& key) {
-  WriteBatch batch;
-  batch.Delete(column_family, key);
+  if (nullptr == opt.timestamp) {
+    WriteBatch batch;
+    Status s = batch.Delete(column_family, key);
+    if (!s.ok()) {
+      return s;
+    }
+    return Write(opt, &batch);
+  }
+  const Slice* ts = opt.timestamp;
+  assert(ts != nullptr);
+  const size_t ts_sz = ts->size();
+  constexpr size_t kKeyAndValueLenSize = 11;
+  constexpr size_t kWriteBatchOverhead =
+      WriteBatchInternal::kHeader + sizeof(ValueType) + kKeyAndValueLenSize;
+  WriteBatch batch(key.size() + ts_sz + kWriteBatchOverhead, /*max_bytes=*/0,
+                   ts_sz);
+  Status s = batch.Delete(column_family, key);
+  if (!s.ok()) {
+    return s;
+  }
+  s = batch.AssignTimestamp(*ts);
+  if (!s.ok()) {
+    return s;
+  }
  return Write(opt, &batch);
 }

@@ -45,6 +45,8 @@ class DBSecondaryTest : public DBTestBase {

  void OpenSecondary(const Options& options);

+  Status TryOpenSecondary(const Options& options);
+
  void OpenSecondaryWithColumnFamilies(
      const std::vector<std::string>& column_families, const Options& options);

@@ -70,9 +72,13 @@ class DBSecondaryTest : public DBTestBase {
 };

 void DBSecondaryTest::OpenSecondary(const Options& options) {
+  ASSERT_OK(TryOpenSecondary(options));
+}
+
+Status DBSecondaryTest::TryOpenSecondary(const Options& options) {
  Status s =
      DB::OpenAsSecondary(options, dbname_, secondary_path_, &db_secondary_);
-  ASSERT_OK(s);
+  return s;
 }

 void DBSecondaryTest::OpenSecondaryWithColumnFamilies(
@@ -858,6 +864,56 @@ TEST_F(DBSecondaryTest, CheckConsistencyWhenOpen) {
  thread.join();
  ASSERT_TRUE(called);
 }
+
+TEST_F(DBSecondaryTest, StartFromInconsistent) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value"));
+  ASSERT_OK(Flush());
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionBuilder::CheckConsistencyBeforeReturn", [&](void* arg) {
+        ASSERT_NE(nullptr, arg);
+        *(reinterpret_cast<Status*>(arg)) =
+            Status::Corruption("Inject corruption");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  Options options1;
+  Status s = TryOpenSecondary(options1);
+  ASSERT_TRUE(s.IsCorruption());
+}
+
+TEST_F(DBSecondaryTest, InconsistencyDuringCatchUp) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value"));
+  ASSERT_OK(Flush());
+
+  Options options1;
+  OpenSecondary(options1);
+
+  {
+    std::string value;
+    ASSERT_OK(db_secondary_->Get(ReadOptions(), "foo", &value));
+    ASSERT_EQ("value", value);
+  }
+
+  ASSERT_OK(Put("bar", "value1"));
+  ASSERT_OK(Flush());
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionBuilder::CheckConsistencyBeforeReturn", [&](void* arg) {
+        ASSERT_NE(nullptr, arg);
+        *(reinterpret_cast<Status*>(arg)) =
+            Status::Corruption("Inject corruption");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  Status s = db_secondary_->TryCatchUpWithPrimary();
+  ASSERT_TRUE(s.IsCorruption());
+}
 #endif  //! ROCKSDB_LITE

 }  // namespace ROCKSDB_NAMESPACE
@@ -73,6 +73,7 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
      cfd_(cfd),
      start_seqnum_(read_options.iter_start_seqnum),
      timestamp_ub_(read_options.timestamp),
+      timestamp_lb_(read_options.iter_start_ts),
      timestamp_size_(timestamp_ub_ ? timestamp_ub_->size() : 0) {
  RecordTick(statistics_, NO_ITERATOR_CREATED);
  if (pin_thru_lifetime_) {
@@ -246,27 +247,36 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,

    assert(ikey_.user_key.size() >= timestamp_size_);
    Slice ts;
+    bool more_recent = false;
    if (timestamp_size_ > 0) {
      ts = ExtractTimestampFromUserKey(ikey_.user_key, timestamp_size_);
    }
-    if (IsVisible(ikey_.sequence, ts)) {
+    if (IsVisible(ikey_.sequence, ts, &more_recent)) {
      // If the previous entry is of seqnum 0, the current entry will not
      // possibly be skipped. This condition can potentially be relaxed to
      // prev_key.seq <= ikey_.sequence. We are cautious because it will be more
      // prone to bugs causing the same user key with the same sequence number.
-      if (!is_prev_key_seqnum_zero && skipping_saved_key &&
-          user_comparator_.CompareWithoutTimestamp(
-              ikey_.user_key, saved_key_.GetUserKey()) <= 0) {
+      // Note that with current timestamp implementation, the same user key can
+      // have different timestamps and zero sequence number on the bottommost
+      // level. This may change in the future.
+      if ((!is_prev_key_seqnum_zero || timestamp_size_ > 0) &&
+          skipping_saved_key &&
+          CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) <= 0) {
        num_skipped++;  // skip this entry
        PERF_COUNTER_ADD(internal_key_skipped_count, 1);
      } else {
        assert(!skipping_saved_key ||
-               user_comparator_.CompareWithoutTimestamp(
-                   ikey_.user_key, saved_key_.GetUserKey()) > 0);
+               CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) > 0);
+        if (!iter_.PrepareValue()) {
+          assert(!iter_.status().ok());
+          valid_ = false;
+          return false;
+        }
        num_skipped = 0;
        reseek_done = false;
        switch (ikey_.type) {
          case kTypeDeletion:
+          case kTypeDeletionWithTimestamp:
          case kTypeSingleDeletion:
            // Arrange to skip all upcoming entries for this key since
            // they are hidden by this deletion.
@@ -363,11 +373,13 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
        }
      }
    } else {
-      PERF_COUNTER_ADD(internal_recent_skipped_count, 1);
+      if (more_recent) {
+        PERF_COUNTER_ADD(internal_recent_skipped_count, 1);
+      }

-      // This key was inserted after our snapshot was taken.
-      // If this happens too many times in a row for the same user key, we want
-      // to seek to the target sequence number.
+      // This key was inserted after our snapshot was taken or skipped by
+      // timestamp range. If this happens too many times in a row for the same
+      // user key, we want to seek to the target sequence number.
      int cmp = user_comparator_.CompareWithoutTimestamp(
          ikey_.user_key, saved_key_.GetUserKey());
      if (cmp == 0 || (skipping_saved_key && cmp < 0)) {
@@ -446,6 +458,7 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
 // Scan from the newer entries to older entries.
 // PRE: iter_.key() points to the first merge type entry
 //      saved_key_ stores the user key
+//      iter_.PrepareValue() has been called
 // POST: saved_value_ has the merged value for the user key
 //       iter_ points to the next entry (or invalid)
 bool DBIter::MergeValuesNewToOld() {
@@ -475,14 +488,21 @@ bool DBIter::MergeValuesNewToOld() {
    if (!user_comparator_.Equal(ikey.user_key, saved_key_.GetUserKey())) {
      // hit the next user key, stop right here
      break;
-    } else if (kTypeDeletion == ikey.type || kTypeSingleDeletion == ikey.type ||
+    }
+    if (kTypeDeletion == ikey.type || kTypeSingleDeletion == ikey.type ||
               range_del_agg_.ShouldDelete(
                   ikey, RangeDelPositioningMode::kForwardTraversal)) {
      // hit a delete with the same user key, stop right here
      // iter_ is positioned after delete
      iter_.Next();
      break;
-    } else if (kTypeValue == ikey.type) {
+    }
+    if (!iter_.PrepareValue()) {
+      valid_ = false;
+      return false;
+    }
+
+    if (kTypeValue == ikey.type) {
      // hit a put, merge the put value with operands and store the
      // final result in saved_value_. We are done!
      const Slice val = iter_.value();
@@ -754,6 +774,11 @@ bool DBIter::FindValueForCurrentKey() {
      return FindValueForCurrentKeyUsingSeek();
    }

+    if (!iter_.PrepareValue()) {
+      valid_ = false;
+      return false;
+    }
+
    last_key_entry_type = ikey.type;
    switch (last_key_entry_type) {
      case kTypeValue:
@@ -931,6 +956,10 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
    valid_ = false;
    return false;
  }
+  if (!iter_.PrepareValue()) {
+    valid_ = false;
+    return false;
+  }
  if (ikey.type == kTypeValue || ikey.type == kTypeBlobIndex) {
    assert(iter_.iter()->IsValuePinned());
    pinned_value_ = iter_.value();
@@ -962,12 +991,17 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
    if (!user_comparator_.Equal(ikey.user_key, saved_key_.GetUserKey())) {
      break;
    }
-
    if (ikey.type == kTypeDeletion || ikey.type == kTypeSingleDeletion ||
        range_del_agg_.ShouldDelete(
            ikey, RangeDelPositioningMode::kForwardTraversal)) {
      break;
-    } else if (ikey.type == kTypeValue) {
+    }
+    if (!iter_.PrepareValue()) {
+      valid_ = false;
+      return false;
+    }
+
+    if (ikey.type == kTypeValue) {
      const Slice val = iter_.value();
      Status s = MergeHelper::TimedFullMerge(
          merge_operator_, saved_key_.GetUserKey(), &val,
@@ -1101,20 +1135,24 @@ bool DBIter::TooManyInternalKeysSkipped(bool increment) {
  return false;
 }

-bool DBIter::IsVisible(SequenceNumber sequence, const Slice& ts) {
+bool DBIter::IsVisible(SequenceNumber sequence, const Slice& ts,
+                       bool* more_recent) {
  // Remember that comparator orders preceding timestamp as larger.
-  int cmp_ts = timestamp_ub_ != nullptr
-                   ? user_comparator_.CompareTimestamp(ts, *timestamp_ub_)
-                   : 0;
-  if (cmp_ts > 0) {
-    return false;
-  }
-  if (read_callback_ == nullptr) {
-    return sequence <= sequence_;
-  } else {
-    // TODO(yanqin): support timestamp in read_callback_.
-    return read_callback_->IsVisible(sequence);
+  // TODO(yanqin): support timestamp in read_callback_.
+  bool visible_by_seq = (read_callback_ == nullptr)
+                            ? sequence <= sequence_
+                            : read_callback_->IsVisible(sequence);
+
+  bool visible_by_ts =
+      (timestamp_ub_ == nullptr ||
+       user_comparator_.CompareTimestamp(ts, *timestamp_ub_) <= 0) &&
+      (timestamp_lb_ == nullptr ||
+       user_comparator_.CompareTimestamp(ts, *timestamp_lb_) >= 0);
+
+  if (more_recent) {
+    *more_recent = !visible_by_seq;
  }
+  return visible_by_seq && visible_by_ts;
 }

 void DBIter::SetSavedKeyToSeekTarget(const Slice& target) {
@@ -231,7 +231,8 @@ class DBIter final : public Iterator {
  // entry can be found within the prefix.
  void PrevInternal(const Slice* prefix);
  bool TooManyInternalKeysSkipped(bool increment = true);
-  bool IsVisible(SequenceNumber sequence, const Slice& ts);
+  bool IsVisible(SequenceNumber sequence, const Slice& ts,
+                 bool* more_recent = nullptr);

  // Temporarily pin the blocks that we encounter until ReleaseTempPinnedData()
  // is called
@@ -270,6 +271,15 @@ class DBIter final : public Iterator {
    return expect_total_order_inner_iter_;
  }

+  // If lower bound of timestamp is given by ReadOptions.iter_start_ts, we need
+  // to return versions of the same key. We cannot just skip if the key value
+  // is the same but timestamps are different but fall in timestamp range.
+  inline int CompareKeyForSkip(const Slice& a, const Slice& b) {
+    return timestamp_lb_ != nullptr
+               ? user_comparator_.Compare(a, b)
+               : user_comparator_.CompareWithoutTimestamp(a, b);
+  }
+
  const SliceTransform* prefix_extractor_;
  Env* const env_;
  Logger* logger_;
@@ -338,6 +348,7 @@ class DBIter final : public Iterator {
  // if this value > 0 iterator will return internal keys
  SequenceNumber start_seqnum_;
  const Slice* const timestamp_ub_;
+  const Slice* const timestamp_lb_;
  const size_t timestamp_size_;
 };

@@ -1167,32 +1167,62 @@ TEST_P(DBIteratorTest, IndexWithFirstKey) {
    ropt.tailing = tailing;
    std::unique_ptr<Iterator> iter(NewIterator(ropt));

+    ropt.read_tier = ReadTier::kBlockCacheTier;
+    std::unique_ptr<Iterator> nonblocking_iter(NewIterator(ropt));
+
    iter->Seek("b10");
    ASSERT_TRUE(iter->Valid());
    EXPECT_EQ("b2", iter->key().ToString());
    EXPECT_EQ("y2", iter->value().ToString());
    EXPECT_EQ(1, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));

+    // The cache-only iterator should succeed too, using the blocks pulled into
+    // the cache by the previous iterator.
+    nonblocking_iter->Seek("b10");
+    ASSERT_TRUE(nonblocking_iter->Valid());
+    EXPECT_EQ("b2", nonblocking_iter->key().ToString());
+    EXPECT_EQ("y2", nonblocking_iter->value().ToString());
+    EXPECT_EQ(1, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+
+    // ... but it shouldn't be able to step forward since the next block is
+    // not in cache yet.
+    nonblocking_iter->Next();
+    ASSERT_FALSE(nonblocking_iter->Valid());
+    ASSERT_TRUE(nonblocking_iter->status().IsIncomplete());
+
+    // ... nor should a seek to the next key succeed.
+    nonblocking_iter->Seek("b20");
+    ASSERT_FALSE(nonblocking_iter->Valid());
+    ASSERT_TRUE(nonblocking_iter->status().IsIncomplete());
+
    iter->Next();
    ASSERT_TRUE(iter->Valid());
    EXPECT_EQ("b3", iter->key().ToString());
    EXPECT_EQ("y3", iter->value().ToString());
-    EXPECT_EQ(2, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
-    EXPECT_EQ(0, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+    EXPECT_EQ(4, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
+    EXPECT_EQ(1, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+
+    // After the blocking iterator loaded the next block, the nonblocking
+    // iterator's seek should succeed.
+    nonblocking_iter->Seek("b20");
+    ASSERT_TRUE(nonblocking_iter->Valid());
+    EXPECT_EQ("b3", nonblocking_iter->key().ToString());
+    EXPECT_EQ("y3", nonblocking_iter->value().ToString());
+    EXPECT_EQ(2, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));

    iter->Seek("c0");
    ASSERT_TRUE(iter->Valid());
    EXPECT_EQ("c0", iter->key().ToString());
    EXPECT_EQ("z1,z2", iter->value().ToString());
-    EXPECT_EQ(0, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
-    EXPECT_EQ(4, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
+    EXPECT_EQ(2, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+    EXPECT_EQ(6, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));

    iter->Next();
    ASSERT_TRUE(iter->Valid());
    EXPECT_EQ("c3", iter->key().ToString());
    EXPECT_EQ("z3", iter->value().ToString());
-    EXPECT_EQ(0, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
-    EXPECT_EQ(5, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
+    EXPECT_EQ(2, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+    EXPECT_EQ(7, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));

    iter.reset();

@@ -1207,13 +1237,13 @@ TEST_P(DBIteratorTest, IndexWithFirstKey) {
    ASSERT_TRUE(iter->Valid());
    EXPECT_EQ("b2", iter->key().ToString());
    EXPECT_EQ("y2", iter->value().ToString());
-    EXPECT_EQ(1, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
-    EXPECT_EQ(5, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
+    EXPECT_EQ(3, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+    EXPECT_EQ(7, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));

    iter->Next();
    ASSERT_FALSE(iter->Valid());
-    EXPECT_EQ(1, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
-    EXPECT_EQ(5, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
+    EXPECT_EQ(3, stats->getTickerCount(BLOCK_CACHE_DATA_HIT));
+    EXPECT_EQ(7, stats->getTickerCount(BLOCK_CACHE_DATA_MISS));
  }
 }

@@ -37,17 +37,15 @@ class DBLogicalBlockSizeCacheTest : public testing::Test {
        data_path_1_(dbname_ + "/data_path_1"),
        cf_path_0_(dbname_ + "/cf_path_0"),
        cf_path_1_(dbname_ + "/cf_path_1") {
-    auto get_fd_block_size = [&](int fd) {
-      return fd;
-    };
+    auto get_fd_block_size = [&](int fd) { return fd; };
    auto get_dir_block_size = [&](const std::string& /*dir*/, size_t* size) {
      *size = 1024;
      return Status::OK();
    };
-    cache_.reset(new LogicalBlockSizeCache(
-        get_fd_block_size, get_dir_block_size));
-    env_.reset(new EnvWithCustomLogicalBlockSizeCache(
-        Env::Default(), cache_.get()));
+    cache_.reset(
+        new LogicalBlockSizeCache(get_fd_block_size, get_dir_block_size));
+    env_.reset(
+        new EnvWithCustomLogicalBlockSizeCache(Env::Default(), cache_.get()));
  }

 protected:
@@ -507,7 +505,7 @@ TEST_F(DBLogicalBlockSizeCacheTest, MultiDBWithSamePaths) {
 }

 }  // namespace ROCKSDB_NAMESPACE
-#endif // OS_LINUX
+#endif  // OS_LINUX

 int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);
@@ -33,13 +33,14 @@ class DBOptionsTest : public DBTestBase {
  std::unordered_map<std::string, std::string> GetMutableDBOptionsMap(
      const DBOptions& options) {
    std::string options_str;
-    GetStringFromDBOptions(&options_str, options);
+    ConfigOptions config_options;
+    config_options.delimiter = "; ";
+    GetStringFromDBOptions(config_options, options, &options_str);
    std::unordered_map<std::string, std::string> options_map;
    StringToMap(options_str, &options_map);
    std::unordered_map<std::string, std::string> mutable_map;
    for (const auto opt : db_options_type_info) {
-      if (opt.second.is_mutable &&
-          opt.second.verification != OptionVerificationType::kDeprecated) {
+      if (opt.second.IsMutable() && opt.second.ShouldSerialize()) {
        mutable_map[opt.first] = options_map[opt.first];
      }
    }
@@ -49,13 +50,15 @@ class DBOptionsTest : public DBTestBase {
  std::unordered_map<std::string, std::string> GetMutableCFOptionsMap(
      const ColumnFamilyOptions& options) {
    std::string options_str;
-    GetStringFromColumnFamilyOptions(&options_str, options);
+    ConfigOptions config_options;
+    config_options.delimiter = "; ";
+
+    GetStringFromColumnFamilyOptions(config_options, options, &options_str);
    std::unordered_map<std::string, std::string> options_map;
    StringToMap(options_str, &options_map);
    std::unordered_map<std::string, std::string> mutable_map;
    for (const auto opt : cf_options_type_info) {
-      if (opt.second.is_mutable &&
-          opt.second.verification != OptionVerificationType::kDeprecated) {
+      if (opt.second.IsMutable() && opt.second.ShouldSerialize()) {
        mutable_map[opt.first] = options_map[opt.first];
      }
    }
@@ -404,6 +407,20 @@ TEST_F(DBOptionsTest, SetBackgroundCompactionThreads) {
  ASSERT_EQ(3, dbfull()->TEST_BGCompactionsAllowed());
 }

+TEST_F(DBOptionsTest, SetBackgroundFlushThreads) {
+  Options options;
+  options.create_if_missing = true;
+  options.max_background_flushes = 1;
+  options.env = env_;
+  Reopen(options);
+  ASSERT_EQ(1, dbfull()->TEST_BGFlushesAllowed());
+  ASSERT_EQ(1, env_->GetBackgroundThreads(Env::Priority::HIGH));
+  ASSERT_OK(dbfull()->SetDBOptions({{"max_background_flushes", "3"}}));
+  ASSERT_EQ(3, env_->GetBackgroundThreads(Env::Priority::HIGH));
+  ASSERT_EQ(3, dbfull()->TEST_BGFlushesAllowed());
+}
+
+
 TEST_F(DBOptionsTest, SetBackgroundJobs) {
  Options options;
  options.create_if_missing = true;
@@ -859,6 +876,66 @@ TEST_F(DBOptionsTest, FIFOTtlBackwardCompatible) {
  ASSERT_EQ(dbfull()->GetOptions().ttl, 191);
 }

+TEST_F(DBOptionsTest, ChangeCompression) {
+  if (!Snappy_Supported() || !LZ4_Supported()) {
+    return;
+  }
+  Options options;
+  options.write_buffer_size = 10 << 10;  // 10KB
+  options.level0_file_num_compaction_trigger = 2;
+  options.create_if_missing = true;
+  options.compression = CompressionType::kLZ4Compression;
+  options.bottommost_compression = CompressionType::kNoCompression;
+  options.bottommost_compression_opts.level = 2;
+  options.bottommost_compression_opts.parallel_threads = 1;
+
+  ASSERT_OK(TryReopen(options));
+
+  CompressionType compression_used = CompressionType::kLZ4Compression;
+  CompressionOptions compression_opt_used;
+  bool compacted = false;
+  SyncPoint::GetInstance()->SetCallBack(
+      "LevelCompactionPicker::PickCompaction:Return", [&](void* arg) {
+        Compaction* c = reinterpret_cast<Compaction*>(arg);
+        compression_used = c->output_compression();
+        compression_opt_used = c->output_compression_opts();
+        compacted = true;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(Put("foo", "foofoofoo"));
+  ASSERT_OK(Put("bar", "foofoofoo"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("foo", "foofoofoo"));
+  ASSERT_OK(Put("bar", "foofoofoo"));
+  ASSERT_OK(Flush());
+  dbfull()->TEST_WaitForCompact();
+  ASSERT_TRUE(compacted);
+  ASSERT_EQ(CompressionType::kNoCompression, compression_used);
+  ASSERT_EQ(options.compression_opts.level, compression_opt_used.level);
+  ASSERT_EQ(options.compression_opts.parallel_threads,
+            compression_opt_used.parallel_threads);
+
+  compression_used = CompressionType::kLZ4Compression;
+  compacted = false;
+  ASSERT_OK(dbfull()->SetOptions(
+      {{"bottommost_compression", "kSnappyCompression"},
+       {"bottommost_compression_opts", "0:6:0:0:4:true"}}));
+  ASSERT_OK(Put("foo", "foofoofoo"));
+  ASSERT_OK(Put("bar", "foofoofoo"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("foo", "foofoofoo"));
+  ASSERT_OK(Put("bar", "foofoofoo"));
+  ASSERT_OK(Flush());
+  dbfull()->TEST_WaitForCompact();
+  ASSERT_TRUE(compacted);
+  ASSERT_EQ(CompressionType::kSnappyCompression, compression_used);
+  ASSERT_EQ(6, compression_opt_used.level);
+  // Right now parallel_level is not yet allowed to be changed.
+
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
 #endif  // ROCKSDB_LITE

 }  // namespace ROCKSDB_NAMESPACE
@@ -47,6 +47,21 @@ TEST_F(DBRangeDelTest, WriteBatchWithIndexNotSupported) {
  ASSERT_TRUE(indexedBatch.DeleteRange("dr1", "dr1").IsNotSupported());
 }

+TEST_F(DBRangeDelTest, EndSameAsStartCoversNothing) {
+  ASSERT_OK(db_->Put(WriteOptions(), "b", "val"));
+  ASSERT_OK(
+      db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "b", "b"));
+  ASSERT_EQ("val", Get("b"));
+}
+
+TEST_F(DBRangeDelTest, EndComesBeforeStartInvalidArgument) {
+  db_->Put(WriteOptions(), "b", "val");
+  ASSERT_TRUE(
+      db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(), "b", "a")
+          .IsInvalidArgument());
+  ASSERT_EQ("val", Get("b"));
+}
+
 TEST_F(DBRangeDelTest, FlushOutputHasOnlyRangeTombstones) {
  do {
    DestroyAndReopen(CurrentOptions());
@@ -174,7 +189,7 @@ TEST_F(DBRangeDelTest, MaxCompactionBytesCutsOutputFiles) {
  std::vector<std::vector<FileMetaData>> files;
  dbfull()->TEST_GetFilesMetaData(db_->DefaultColumnFamily(), &files);

-  for (size_t i = 0; i < files[1].size() - 1; ++i) {
+  for (size_t i = 0; i + 1 < files[1].size(); ++i) {
    ASSERT_TRUE(InternalKeyComparator(opts.comparator)
                    .Compare(files[1][i].largest, files[1][i + 1].smallest) <
                0);
@@ -356,38 +356,27 @@ TEST_F(DBSSTTest, RateLimitedDelete) {
      "InstrumentedCondVar::TimedWaitInternal", [&](void* arg) {
        // Turn timed wait into a simulated sleep
        uint64_t* abs_time_us = static_cast<uint64_t*>(arg);
-        int64_t cur_time = 0;
-        env_->GetCurrentTime(&cur_time);
-        if (*abs_time_us > static_cast<uint64_t>(cur_time)) {
-          env_->addon_time_.fetch_add(*abs_time_us -
-                                      static_cast<uint64_t>(cur_time));
+        uint64_t cur_time = env_->NowMicros();
+        if (*abs_time_us > cur_time) {
+          env_->addon_time_.fetch_add(*abs_time_us - cur_time);
        }

        // Randomly sleep shortly
        env_->addon_time_.fetch_add(
            static_cast<uint64_t>(Random::GetTLSInstance()->Uniform(10)));

-        // Set wait until time to before current to force not to sleep.
-        int64_t real_cur_time = 0;
-        Env::Default()->GetCurrentTime(&real_cur_time);
-        *abs_time_us = static_cast<uint64_t>(real_cur_time);
+        // Set wait until time to before (actual) current time to force not
+        // to sleep
+        *abs_time_us = Env::Default()->NowMicros();
      });

  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();

-  env_->no_slowdown_ = true;
-  env_->time_elapse_only_sleep_ = true;
  Options options = CurrentOptions();
+  env_->SetTimeElapseOnlySleep(&options);
  options.disable_auto_compactions = true;
-  // Need to disable stats dumping and persisting which also use
-  // RepeatableThread, one of whose member variables is of type
-  // InstrumentedCondVar. The callback for
-  // InstrumentedCondVar::TimedWaitInternal can be triggered by stats dumping
-  // and persisting threads and cause time_spent_deleting measurement to become
-  // incorrect.
-  options.stats_dump_period_sec = 0;
-  options.stats_persist_period_sec = 0;
  options.env = env_;
+  options.statistics = CreateDBStatistics();

  int64_t rate_bytes_per_sec = 1024 * 10;  // 10 Kbs / Sec
  Status s;
@@ -437,6 +426,9 @@ TEST_F(DBSSTTest, RateLimitedDelete) {
  }
  ASSERT_GT(time_spent_deleting, expected_penlty * 0.9);
  ASSERT_LT(time_spent_deleting, expected_penlty * 1.1);
+  ASSERT_EQ(4, options.statistics->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(
+      0, options.statistics->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));

  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
@@ -828,6 +820,12 @@ TEST_F(DBSSTTest, CancellingCompactionsWorks) {
  ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
  // Make sure the stat is bumped
  ASSERT_GT(dbfull()->immutable_db_options().statistics.get()->getTickerCount(COMPACTION_CANCELLED), 0);
+  ASSERT_EQ(0,
+            dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                FILES_MARKED_TRASH));
+  ASSERT_EQ(4,
+            dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                FILES_DELETED_IMMEDIATELY));
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }

@@ -45,7 +45,8 @@ void VerifyTableProperties(DB* db, uint64_t expected_entries_size) {
 }
 }  // namespace

-class DBTablePropertiesTest : public DBTestBase {
+class DBTablePropertiesTest : public DBTestBase,
+                              public testing::WithParamInterface<std::string> {
 public:
  DBTablePropertiesTest() : DBTestBase("/db_table_properties_test") {}
  TablePropertiesCollection TestGetPropertiesOfTablesInRange(
@@ -251,7 +252,20 @@ TEST_F(DBTablePropertiesTest, GetColumnFamilyNameProperty) {
  }
 }

-TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {
+class DeletionTriggeredCompactionTestListener : public EventListener {
+ public:
+  void OnCompactionBegin(DB* , const CompactionJobInfo& ci) override {
+    ASSERT_EQ(ci.compaction_reason,
+              CompactionReason::kFilesMarkedForCompaction);
+  }
+
+  void OnCompactionCompleted(DB* , const CompactionJobInfo& ci) override {
+    ASSERT_EQ(ci.compaction_reason,
+              CompactionReason::kFilesMarkedForCompaction);
+  }
+};
+
+TEST_P(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {
  int kNumKeys = 1000;
  int kWindowSize = 100;
  int kNumDelsTrigger = 90;
@@ -260,6 +274,10 @@ TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {

  Options opts = CurrentOptions();
  opts.table_properties_collector_factories.emplace_back(compact_on_del);
+
+  if(GetParam() == "kCompactionStyleUniversal") {
+    opts.compaction_style = kCompactionStyleUniversal;
+  }
  Reopen(opts);

  // add an L1 file to prevent tombstones from dropping due to obsolescence
@@ -268,6 +286,11 @@ TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {
  Flush();
  MoveFilesToLevel(1);

+  DeletionTriggeredCompactionTestListener *listener =
+    new DeletionTriggeredCompactionTestListener();
+  opts.listeners.emplace_back(listener);
+  Reopen(opts);
+
  for (int i = 0; i < kNumKeys; ++i) {
    if (i >= kNumKeys - kWindowSize &&
        i < kNumKeys - kWindowSize + kNumDelsTrigger) {
@@ -280,7 +303,6 @@ TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {

  dbfull()->TEST_WaitForCompact();
  ASSERT_EQ(0, NumTableFilesAtLevel(0));
-  ASSERT_GT(NumTableFilesAtLevel(1), 0);

  // Change the window size and deletion trigger and ensure new values take
  // effect
@@ -302,7 +324,6 @@ TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {

  dbfull()->TEST_WaitForCompact();
  ASSERT_EQ(0, NumTableFilesAtLevel(0));
-  ASSERT_GT(NumTableFilesAtLevel(1), 0);

  // Change the window size to disable delete triggered compaction
  kWindowSize = 0;
@@ -322,9 +343,16 @@ TEST_F(DBTablePropertiesTest, DeletionTriggeredCompactionMarking) {

  dbfull()->TEST_WaitForCompact();
  ASSERT_EQ(1, NumTableFilesAtLevel(0));
-
 }

+INSTANTIATE_TEST_CASE_P(
+    DBTablePropertiesTest,
+    DBTablePropertiesTest,
+    ::testing::Values(
+      "kCompactionStyleLevel",
+      "kCompactionStyleUniversal"
+      ));
+
 }  // namespace ROCKSDB_NAMESPACE

 #endif  // ROCKSDB_LITE
@@ -1421,7 +1421,7 @@ TEST_F(DBTest, ApproximateSizesMemTable) {
    keys[i * 3 + 1] = i * 5 + 1;
    keys[i * 3 + 2] = i * 5 + 2;
  }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  RandomShuffle(std::begin(keys), std::end(keys));

  for (int i = 0; i < N * 3; i++) {
    ASSERT_OK(Put(Key(keys[i] + 1000), RandomString(&rnd, 1024)));
@@ -1489,18 +1489,24 @@ TEST_F(DBTest, ApproximateSizesMemTable) {
 }

 TEST_F(DBTest, ApproximateSizesFilesWithErrorMargin) {
+  // Roughly 4 keys per data block, 1000 keys per file,
+  // with filter substantially larger than a data block
+  BlockBasedTableOptions table_options;
+  table_options.filter_policy.reset(NewBloomFilterPolicy(16));
+  table_options.block_size = 100;
  Options options = CurrentOptions();
-  options.write_buffer_size = 1024 * 1024;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  options.write_buffer_size = 24 * 1024;
  options.compression = kNoCompression;
  options.create_if_missing = true;
-  options.target_file_size_base = 1024 * 1024;
+  options.target_file_size_base = 24 * 1024;
  DestroyAndReopen(options);
  const auto default_cf = db_->DefaultColumnFamily();

  const int N = 64000;
  Random rnd(301);
  for (int i = 0; i < N; i++) {
-    ASSERT_OK(Put(Key(i), RandomString(&rnd, 1024)));
+    ASSERT_OK(Put(Key(i), RandomString(&rnd, 24)));
  }
  // Flush everything to files
  Flush();
@@ -1509,7 +1515,7 @@ TEST_F(DBTest, ApproximateSizesFilesWithErrorMargin) {

  // Write more keys
  for (int i = N; i < (N + N / 4); i++) {
-    ASSERT_OK(Put(Key(i), RandomString(&rnd, 1024)));
+    ASSERT_OK(Put(Key(i), RandomString(&rnd, 24)));
  }
  // Flush everything to files again
  Flush();
@@ -1517,27 +1523,45 @@ TEST_F(DBTest, ApproximateSizesFilesWithErrorMargin) {
  // Wait for compaction to finish
  ASSERT_OK(dbfull()->TEST_WaitForCompact());

-  const std::string start = Key(0);
-  const std::string end = Key(2 * N);
-  const Range r(start, end);
+  {
+    const std::string start = Key(0);
+    const std::string end = Key(2 * N);
+    const Range r(start, end);

-  SizeApproximationOptions size_approx_options;
-  size_approx_options.include_memtabtles = false;
-  size_approx_options.include_files = true;
-  size_approx_options.files_size_error_margin = -1.0;  // disabled
+    SizeApproximationOptions size_approx_options;
+    size_approx_options.include_memtabtles = false;
+    size_approx_options.include_files = true;
+    size_approx_options.files_size_error_margin = -1.0;  // disabled

-  // Get the precise size without any approximation heuristic
-  uint64_t size;
-  db_->GetApproximateSizes(size_approx_options, default_cf, &r, 1, &size);
-  ASSERT_NE(size, 0);
+    // Get the precise size without any approximation heuristic
+    uint64_t size;
+    db_->GetApproximateSizes(size_approx_options, default_cf, &r, 1, &size);
+    ASSERT_NE(size, 0);

-  // Get the size with an approximation heuristic
-  uint64_t size2;
-  const double error_margin = 0.2;
-  size_approx_options.files_size_error_margin = error_margin;
-  db_->GetApproximateSizes(size_approx_options, default_cf, &r, 1, &size2);
-  ASSERT_LT(size2, size * (1 + error_margin));
-  ASSERT_GT(size2, size * (1 - error_margin));
+    // Get the size with an approximation heuristic
+    uint64_t size2;
+    const double error_margin = 0.2;
+    size_approx_options.files_size_error_margin = error_margin;
+    db_->GetApproximateSizes(size_approx_options, default_cf, &r, 1, &size2);
+    ASSERT_LT(size2, size * (1 + error_margin));
+    ASSERT_GT(size2, size * (1 - error_margin));
+  }
+
+  {
+    // Ensure that metadata is not falsely attributed only to the last data in
+    // the file. (In some applications, filters can be large portion of data
+    // size.)
+    // Perform many queries over small range, enough to ensure crossing file
+    // boundary, and make sure we never see a spike for large filter.
+    for (int i = 0; i < 3000; i += 10) {
+      const std::string start = Key(i);
+      const std::string end = Key(i + 11);  // overlap by 1 key
+      const Range r(start, end);
+      uint64_t size;
+      db_->GetApproximateSizes(&r, 1, &size);
+      ASSERT_LE(size, 11 * 100);
+    }
+  }
 }

 TEST_F(DBTest, GetApproximateMemTableStats) {
@@ -1675,12 +1699,13 @@ TEST_F(DBTest, ApproximateSizes_MixOfSmallAndLarge) {
      ASSERT_TRUE(Between(Size("", Key(2), 1), 20000, 21000));
      ASSERT_TRUE(Between(Size("", Key(3), 1), 120000, 121000));
      ASSERT_TRUE(Between(Size("", Key(4), 1), 130000, 131000));
-      ASSERT_TRUE(Between(Size("", Key(5), 1), 230000, 231000));
-      ASSERT_TRUE(Between(Size("", Key(6), 1), 240000, 241000));
-      ASSERT_TRUE(Between(Size("", Key(7), 1), 540000, 541000));
-      ASSERT_TRUE(Between(Size("", Key(8), 1), 550000, 560000));
+      ASSERT_TRUE(Between(Size("", Key(5), 1), 230000, 232000));
+      ASSERT_TRUE(Between(Size("", Key(6), 1), 240000, 242000));
+      // Ensure some overhead is accounted for, even without including all
+      ASSERT_TRUE(Between(Size("", Key(7), 1), 540500, 545000));
+      ASSERT_TRUE(Between(Size("", Key(8), 1), 550500, 555000));

-      ASSERT_TRUE(Between(Size(Key(3), Key(5), 1), 110000, 111000));
+      ASSERT_TRUE(Between(Size(Key(3), Key(5), 1), 110100, 111000));

      dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
    }
@@ -2309,6 +2334,42 @@ TEST_F(DBTest, ReadonlyDBGetLiveManifestSize) {
    Close();
  } while (ChangeCompactOptions());
 }
+
+TEST_F(DBTest, GetLiveBlobFiles) {
+  VersionSet* const versions = dbfull()->TEST_GetVersionSet();
+  assert(versions);
+  assert(versions->GetColumnFamilySet());
+
+  ColumnFamilyData* const cfd = versions->GetColumnFamilySet()->GetDefault();
+  assert(cfd);
+
+  // Add a live blob file.
+  VersionEdit edit;
+
+  constexpr uint64_t blob_file_number = 234;
+  constexpr uint64_t total_blob_count = 555;
+  constexpr uint64_t total_blob_bytes = 66666;
+  constexpr char checksum_method[] = "CRC32";
+  constexpr char checksum_value[] = "3d87ff57";
+
+  edit.AddBlobFile(blob_file_number, total_blob_count, total_blob_bytes,
+                   checksum_method, checksum_value);
+
+  dbfull()->TEST_LockMutex();
+  Status s = versions->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(),
+                                   &edit, dbfull()->mutex());
+  dbfull()->TEST_UnlockMutex();
+
+  ASSERT_OK(s);
+
+  // Make sure it appears in the results returned by GetLiveFiles.
+  uint64_t manifest_size = 0;
+  std::vector<std::string> files;
+  ASSERT_OK(dbfull()->GetLiveFiles(files, &manifest_size));
+
+  ASSERT_FALSE(files.empty());
+  ASSERT_EQ(files[0], BlobFileName("", blob_file_number));
+}
 #endif

 TEST_F(DBTest, PurgeInfoLogs) {
@@ -2929,10 +2990,11 @@ class ModelDB : public DB {

  Status SyncWAL() override { return Status::OK(); }

-#ifndef ROCKSDB_LITE
  Status DisableFileDeletions() override { return Status::OK(); }

  Status EnableFileDeletions(bool /*force*/) override { return Status::OK(); }
+#ifndef ROCKSDB_LITE
+
  Status GetLiveFiles(std::vector<std::string>&, uint64_t* /*size*/,
                      bool /*flush_memtable*/ = true) override {
    return Status::OK();
@@ -4530,7 +4592,7 @@ TEST_F(DBTest, DynamicLevelCompressionPerLevel) {
  for (int i = 0; i < kNKeys; i++) {
    keys[i] = i;
  }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  RandomShuffle(std::begin(keys), std::end(keys));

  Random rnd(301);
  Options options;
@@ -4613,7 +4675,7 @@ TEST_F(DBTest, DynamicLevelCompressionPerLevel2) {
  for (int i = 0; i < kNKeys; i++) {
    keys[i] = i;
  }
-  std::random_shuffle(std::begin(keys), std::end(keys));
+  RandomShuffle(std::begin(keys), std::end(keys));

  Random rnd(301);
  Options options;
@@ -5503,7 +5565,7 @@ TEST_F(DBTest, EmptyCompactedDB) {
 #endif  // ROCKSDB_LITE

 #ifndef ROCKSDB_LITE
-TEST_F(DBTest, SuggestCompactRangeTest) {
+TEST_F(DBTest, DISABLED_SuggestCompactRangeTest) {
  class CompactionFilterFactoryGetContext : public CompactionFilterFactory {
   public:
    std::unique_ptr<CompactionFilter> CreateCompactionFilter(
@@ -5611,6 +5673,7 @@ TEST_F(DBTest, SuggestCompactRangeTest) {
  ASSERT_EQ(1, NumTableFilesAtLevel(1));
 }

+
 TEST_F(DBTest, PromoteL0) {
  Options options = CurrentOptions();
  options.disable_auto_compactions = true;
@@ -25,6 +25,159 @@ class DBTest2 : public DBTestBase {
  DBTest2() : DBTestBase("/db_test2") {}
 };

+#ifndef ROCKSDB_LITE
+TEST_F(DBTest2, OpenForReadOnly) {
+  DB* db_ptr = nullptr;
+  std::string dbname = test::PerThreadDBPath("db_readonly");
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  // OpenForReadOnly should fail but will create <dbname> in the file system
+  ASSERT_NOK(DB::OpenForReadOnly(options, dbname, &db_ptr));
+  // Since <dbname> is created, we should be able to delete the dir
+  // We first get the list files under <dbname>
+  // There should not be any subdirectories -- this is not checked here
+  std::vector<std::string> files;
+  ASSERT_OK(env_->GetChildren(dbname, &files));
+  for (auto& f : files) {
+    if (f != "." && f != "..") {
+      ASSERT_OK(env_->DeleteFile(dbname + "/" + f));
+    }
+  }
+  // <dbname> should be empty now and we should be able to delete it
+  ASSERT_OK(env_->DeleteDir(dbname));
+  options.create_if_missing = false;
+  // OpenForReadOnly should fail since <dbname> was successfully deleted
+  ASSERT_NOK(DB::OpenForReadOnly(options, dbname, &db_ptr));
+  // With create_if_missing false, there should not be a dir in the file system
+  ASSERT_NOK(env_->FileExists(dbname));
+}
+
+TEST_F(DBTest2, OpenForReadOnlyWithColumnFamilies) {
+  DB* db_ptr = nullptr;
+  std::string dbname = test::PerThreadDBPath("db_readonly");
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+
+  ColumnFamilyOptions cf_options(options);
+  std::vector<ColumnFamilyDescriptor> column_families;
+  column_families.push_back(
+      ColumnFamilyDescriptor(kDefaultColumnFamilyName, cf_options));
+  column_families.push_back(ColumnFamilyDescriptor("goku", cf_options));
+  std::vector<ColumnFamilyHandle*> handles;
+  // OpenForReadOnly should fail but will create <dbname> in the file system
+  ASSERT_NOK(
+      DB::OpenForReadOnly(options, dbname, column_families, &handles, &db_ptr));
+  // Since <dbname> is created, we should be able to delete the dir
+  // We first get the list files under <dbname>
+  // There should not be any subdirectories -- this is not checked here
+  std::vector<std::string> files;
+  ASSERT_OK(env_->GetChildren(dbname, &files));
+  for (auto& f : files) {
+    if (f != "." && f != "..") {
+      ASSERT_OK(env_->DeleteFile(dbname + "/" + f));
+    }
+  }
+  // <dbname> should be empty now and we should be able to delete it
+  ASSERT_OK(env_->DeleteDir(dbname));
+  options.create_if_missing = false;
+  // OpenForReadOnly should fail since <dbname> was successfully deleted
+  ASSERT_NOK(
+      DB::OpenForReadOnly(options, dbname, column_families, &handles, &db_ptr));
+  // With create_if_missing false, there should not be a dir in the file system
+  ASSERT_NOK(env_->FileExists(dbname));
+}
+
+class TestReadOnlyWithCompressedCache
+    : public DBTestBase,
+      public testing::WithParamInterface<std::tuple<int, bool>> {
+ public:
+  TestReadOnlyWithCompressedCache()
+      : DBTestBase("/test_readonly_with_compressed_cache") {
+    max_open_files_ = std::get<0>(GetParam());
+    use_mmap_ = std::get<1>(GetParam());
+  }
+  int max_open_files_;
+  bool use_mmap_;
+};
+
+TEST_P(TestReadOnlyWithCompressedCache, ReadOnlyWithCompressedCache) {
+  if (use_mmap_ && !IsMemoryMappedAccessSupported()) {
+    return;
+  }
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Put("foo2", "barbarbarbarbarbarbarbar"));
+  ASSERT_OK(Flush());
+
+  DB* db_ptr = nullptr;
+  Options options = CurrentOptions();
+  options.allow_mmap_reads = use_mmap_;
+  options.max_open_files = max_open_files_;
+  options.compression = kSnappyCompression;
+  BlockBasedTableOptions table_options;
+  table_options.block_cache_compressed = NewLRUCache(8 * 1024 * 1024);
+  table_options.no_block_cache = true;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  options.statistics = CreateDBStatistics();
+
+  ASSERT_OK(DB::OpenForReadOnly(options, dbname_, &db_ptr));
+
+  std::string v;
+  ASSERT_OK(db_ptr->Get(ReadOptions(), "foo", &v));
+  ASSERT_EQ("bar", v);
+  ASSERT_EQ(0, options.statistics->getTickerCount(BLOCK_CACHE_COMPRESSED_HIT));
+  ASSERT_OK(db_ptr->Get(ReadOptions(), "foo", &v));
+  ASSERT_EQ("bar", v);
+  if (Snappy_Supported()) {
+    if (use_mmap_) {
+      ASSERT_EQ(0,
+                options.statistics->getTickerCount(BLOCK_CACHE_COMPRESSED_HIT));
+    } else {
+      ASSERT_EQ(1,
+                options.statistics->getTickerCount(BLOCK_CACHE_COMPRESSED_HIT));
+    }
+  }
+
+  delete db_ptr;
+}
+
+INSTANTIATE_TEST_CASE_P(TestReadOnlyWithCompressedCache,
+                        TestReadOnlyWithCompressedCache,
+                        ::testing::Combine(::testing::Values(-1, 100),
+                                           ::testing::Bool()));
+
+class PartitionedIndexTestListener : public EventListener {
+ public:
+  void OnFlushCompleted(DB* /*db*/, const FlushJobInfo& info) override {
+    ASSERT_GT(info.table_properties.index_partitions, 1);
+    ASSERT_EQ(info.table_properties.index_key_is_user_key, 0);
+  }
+};
+
+TEST_F(DBTest2, PartitionedIndexUserToInternalKey) {
+  BlockBasedTableOptions table_options;
+  Options options = CurrentOptions();
+  table_options.index_type = BlockBasedTableOptions::kTwoLevelIndexSearch;
+  PartitionedIndexTestListener* listener = new PartitionedIndexTestListener();
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  options.listeners.emplace_back(listener);
+  std::vector<const Snapshot*> snapshots;
+  Reopen(options);
+  Random rnd(301);
+
+  for (int i = 0; i < 3000; i++) {
+    int j = i % 30;
+    std::string value = RandomString(&rnd, 10500);
+    ASSERT_OK(Put("keykey_" + std::to_string(j), value));
+    snapshots.push_back(db_->GetSnapshot());
+  }
+  Flush();
+  for (auto s : snapshots) {
+    db_->ReleaseSnapshot(s);
+  }
+}
+
+#endif  // ROCKSDB_LITE
+
 class PrefixFullBloomWithReverseComparator
    : public DBTestBase,
      public ::testing::WithParamInterface<bool> {
@@ -1268,6 +1421,152 @@ class CompactionCompressionListener : public EventListener {
  const Options* db_options_;
 };

+enum CompressionFailureType {
+  kTestCompressionFail,
+  kTestDecompressionFail,
+  kTestDecompressionCorruption
+};
+
+class CompressionFailuresTest
+    : public DBTest2,
+      public testing::WithParamInterface<std::tuple<
+          CompressionFailureType, CompressionType, uint32_t, uint32_t>> {
+ public:
+  CompressionFailuresTest() {
+    std::tie(compression_failure_type_, compression_type_,
+             compression_max_dict_bytes_, compression_parallel_threads_) =
+        GetParam();
+  }
+
+  CompressionFailureType compression_failure_type_ = kTestCompressionFail;
+  CompressionType compression_type_ = kNoCompression;
+  uint32_t compression_max_dict_bytes_ = 0;
+  uint32_t compression_parallel_threads_ = 0;
+};
+
+INSTANTIATE_TEST_CASE_P(
+    DBTest2, CompressionFailuresTest,
+    ::testing::Combine(::testing::Values(kTestCompressionFail,
+                                         kTestDecompressionFail,
+                                         kTestDecompressionCorruption),
+                       ::testing::ValuesIn(GetSupportedCompressions()),
+                       ::testing::Values(0, 10), ::testing::Values(1, 4)));
+
+TEST_P(CompressionFailuresTest, CompressionFailures) {
+  if (compression_type_ == kNoCompression) {
+    return;
+  }
+
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = 2;
+  options.max_bytes_for_level_base = 1024;
+  options.max_bytes_for_level_multiplier = 2;
+  options.num_levels = 7;
+  options.max_background_compactions = 1;
+  options.target_file_size_base = 512;
+
+  BlockBasedTableOptions table_options;
+  table_options.block_size = 512;
+  table_options.verify_compression = true;
+  options.table_factory.reset(new BlockBasedTableFactory(table_options));
+
+  options.compression = compression_type_;
+  options.compression_opts.parallel_threads = compression_parallel_threads_;
+  options.compression_opts.max_dict_bytes = compression_max_dict_bytes_;
+  options.bottommost_compression_opts.parallel_threads =
+      compression_parallel_threads_;
+  options.bottommost_compression_opts.max_dict_bytes =
+      compression_max_dict_bytes_;
+
+  if (compression_failure_type_ == kTestCompressionFail) {
+    ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+        "BlockBasedTableBuilder::CompressBlockInternal:TamperWithReturnValue",
+        [](void* arg) {
+          bool* ret = static_cast<bool*>(arg);
+          *ret = false;
+        });
+  } else if (compression_failure_type_ == kTestDecompressionFail) {
+    ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+        "UncompressBlockContentsForCompressionType:TamperWithReturnValue",
+        [](void* arg) {
+          Status* ret = static_cast<Status*>(arg);
+          ASSERT_OK(*ret);
+          *ret = Status::Corruption("kTestDecompressionFail");
+        });
+  } else if (compression_failure_type_ == kTestDecompressionCorruption) {
+    ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+        "UncompressBlockContentsForCompressionType:"
+        "TamperWithDecompressionOutput",
+        [](void* arg) {
+          BlockContents* contents = static_cast<BlockContents*>(arg);
+          // Ensure uncompressed data != original data
+          const size_t len = contents->data.size() + 1;
+          std::unique_ptr<char[]> fake_data(new char[len]());
+          *contents = BlockContents(std::move(fake_data), len);
+        });
+  }
+
+  std::map<std::string, std::string> key_value_written;
+
+  const int kKeySize = 5;
+  const int kValUnitSize = 16;
+  const int kValSize = 256;
+  Random rnd(405);
+
+  Status s = Status::OK();
+
+  DestroyAndReopen(options);
+  // Write 10 random files
+  for (int i = 0; i < 10; i++) {
+    for (int j = 0; j < 5; j++) {
+      std::string key = RandomString(&rnd, kKeySize);
+      // Ensure good compression ratio
+      std::string valueUnit = RandomString(&rnd, kValUnitSize);
+      std::string value;
+      for (int k = 0; k < kValSize; k += kValUnitSize) {
+        value += valueUnit;
+      }
+      s = Put(key, value);
+      if (compression_failure_type_ == kTestCompressionFail) {
+        key_value_written[key] = value;
+        ASSERT_OK(s);
+      }
+    }
+    s = Flush();
+    if (compression_failure_type_ == kTestCompressionFail) {
+      ASSERT_OK(s);
+    }
+    s = dbfull()->TEST_WaitForCompact();
+    if (compression_failure_type_ == kTestCompressionFail) {
+      ASSERT_OK(s);
+    }
+    if (i == 4) {
+      // Make compression fail at the mid of table building
+      ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+    }
+  }
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+
+  if (compression_failure_type_ == kTestCompressionFail) {
+    // Should be kNoCompression, check content consistency
+    std::unique_ptr<Iterator> db_iter(db_->NewIterator(ReadOptions()));
+    for (db_iter->SeekToFirst(); db_iter->Valid(); db_iter->Next()) {
+      std::string key = db_iter->key().ToString();
+      std::string value = db_iter->value().ToString();
+      ASSERT_NE(key_value_written.find(key), key_value_written.end());
+      ASSERT_EQ(key_value_written[key], value);
+      key_value_written.erase(key);
+    }
+    ASSERT_EQ(0, key_value_written.size());
+  } else if (compression_failure_type_ == kTestDecompressionFail) {
+    ASSERT_EQ(std::string(s.getState()),
+              "Could not decompress: kTestDecompressionFail");
+  } else if (compression_failure_type_ == kTestDecompressionCorruption) {
+    ASSERT_EQ(std::string(s.getState()),
+              "Decompressed block did not match raw block");
+  }
+}
+
 TEST_F(DBTest2, CompressionOptions) {
  if (!Zlib_Supported() || !Snappy_Supported()) {
    return;
@@ -1288,6 +1587,10 @@ TEST_F(DBTest2, CompressionOptions) {
  const int kValSize = 20;
  Random rnd(301);

+  std::vector<uint32_t> compression_parallel_threads = {1, 4};
+
+  std::map<std::string, std::string> key_value_written;
+
  for (int iter = 0; iter <= 2; iter++) {
    listener->max_level_checked = 0;

@@ -1312,19 +1615,37 @@ TEST_F(DBTest2, CompressionOptions) {
      options.bottommost_compression = kDisableCompressionOption;
    }

-    DestroyAndReopen(options);
-    // Write 10 random files
-    for (int i = 0; i < 10; i++) {
-      for (int j = 0; j < 5; j++) {
-        ASSERT_OK(
-            Put(RandomString(&rnd, kKeySize), RandomString(&rnd, kValSize)));
-      }
-      ASSERT_OK(Flush());
-      dbfull()->TEST_WaitForCompact();
-    }
+    for (auto num_threads : compression_parallel_threads) {
+      options.compression_opts.parallel_threads = num_threads;
+      options.bottommost_compression_opts.parallel_threads = num_threads;

-    // Make sure that we wrote enough to check all 7 levels
-    ASSERT_EQ(listener->max_level_checked, 6);
+      DestroyAndReopen(options);
+      // Write 10 random files
+      for (int i = 0; i < 10; i++) {
+        for (int j = 0; j < 5; j++) {
+          std::string key = RandomString(&rnd, kKeySize);
+          std::string value = RandomString(&rnd, kValSize);
+          key_value_written[key] = value;
+          ASSERT_OK(Put(key, value));
+        }
+        ASSERT_OK(Flush());
+        dbfull()->TEST_WaitForCompact();
+      }
+
+      // Make sure that we wrote enough to check all 7 levels
+      ASSERT_EQ(listener->max_level_checked, 6);
+
+      // Make sure database content is the same as key_value_written
+      std::unique_ptr<Iterator> db_iter(db_->NewIterator(ReadOptions()));
+      for (db_iter->SeekToFirst(); db_iter->Valid(); db_iter->Next()) {
+        std::string key = db_iter->key().ToString();
+        std::string value = db_iter->value().ToString();
+        ASSERT_NE(key_value_written.find(key), key_value_written.end());
+        ASSERT_EQ(key_value_written[key], value);
+        key_value_written.erase(key);
+      }
+      ASSERT_EQ(0, key_value_written.size());
+    }
  }
 }

@@ -2666,6 +2987,94 @@ TEST_F(DBTest2, OptimizeForSmallDB) {

 #endif  // ROCKSDB_LITE

+TEST_F(DBTest2, IterRaceFlush1) {
+  ASSERT_OK(Put("foo", "v1"));
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::NewIterator:1", "DBTest2::IterRaceFlush:1"},
+       {"DBTest2::IterRaceFlush:2", "DBImpl::NewIterator:2"}});
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  ROCKSDB_NAMESPACE::port::Thread t1([&] {
+    TEST_SYNC_POINT("DBTest2::IterRaceFlush:1");
+    ASSERT_OK(Put("foo", "v2"));
+    Flush();
+    TEST_SYNC_POINT("DBTest2::IterRaceFlush:2");
+  });
+
+  // iterator is created after the first Put(), so it should see either
+  // "v1" or "v2".
+  {
+    std::unique_ptr<Iterator> it(db_->NewIterator(ReadOptions()));
+    it->Seek("foo");
+    ASSERT_TRUE(it->Valid());
+    ASSERT_EQ("foo", it->key().ToString());
+  }
+
+  t1.join();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+}
+
+TEST_F(DBTest2, IterRaceFlush2) {
+  ASSERT_OK(Put("foo", "v1"));
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::NewIterator:3", "DBTest2::IterRaceFlush2:1"},
+       {"DBTest2::IterRaceFlush2:2", "DBImpl::NewIterator:4"}});
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  ROCKSDB_NAMESPACE::port::Thread t1([&] {
+    TEST_SYNC_POINT("DBTest2::IterRaceFlush2:1");
+    ASSERT_OK(Put("foo", "v2"));
+    Flush();
+    TEST_SYNC_POINT("DBTest2::IterRaceFlush2:2");
+  });
+
+  // iterator is created after the first Put(), so it should see either
+  // "v1" or "v2".
+  {
+    std::unique_ptr<Iterator> it(db_->NewIterator(ReadOptions()));
+    it->Seek("foo");
+    ASSERT_TRUE(it->Valid());
+    ASSERT_EQ("foo", it->key().ToString());
+  }
+
+  t1.join();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+}
+
+TEST_F(DBTest2, IterRefreshRaceFlush) {
+  ASSERT_OK(Put("foo", "v1"));
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+      {{"ArenaWrappedDBIter::Refresh:1", "DBTest2::IterRefreshRaceFlush:1"},
+       {"DBTest2::IterRefreshRaceFlush:2", "ArenaWrappedDBIter::Refresh:2"}});
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  ROCKSDB_NAMESPACE::port::Thread t1([&] {
+    TEST_SYNC_POINT("DBTest2::IterRefreshRaceFlush:1");
+    ASSERT_OK(Put("foo", "v2"));
+    Flush();
+    TEST_SYNC_POINT("DBTest2::IterRefreshRaceFlush:2");
+  });
+
+  // iterator is created after the first Put(), so it should see either
+  // "v1" or "v2".
+  {
+    std::unique_ptr<Iterator> it(db_->NewIterator(ReadOptions()));
+    it->Refresh();
+    it->Seek("foo");
+    ASSERT_TRUE(it->Valid());
+    ASSERT_EQ("foo", it->key().ToString());
+  }
+
+  t1.join();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+}
+
 TEST_F(DBTest2, GetRaceFlush1) {
  ASSERT_OK(Put("foo", "v1"));

@@ -4306,6 +4715,24 @@ TEST_F(DBTest2, SameSmallestInSameLevel) {
  ASSERT_EQ("2,3,4,5,6,7,8", Get("key"));
 }

+TEST_F(DBTest2, FileConsistencyCheckInOpen) {
+  Put("foo", "bar");
+  Flush();
+
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionBuilder::CheckConsistencyBeforeReturn", [&](void* arg) {
+        Status* ret_s = static_cast<Status*>(arg);
+        *ret_s = Status::Corruption("fcc");
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Options options = CurrentOptions();
+  options.force_consistency_checks = true;
+  ASSERT_NOK(TryReopen(options));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
 TEST_F(DBTest2, BlockBasedTablePrefixIndexSeekForPrev) {
  // create a DB with block prefix index
  BlockBasedTableOptions table_options;
@@ -4677,6 +5104,32 @@ TEST_F(DBTest2, AutoPrefixMode1) {
  }
 }
 #endif  // ROCKSDB_LITE
+
+// WAL recovery mode is WALRecoveryMode::kPointInTimeRecovery.
+TEST_F(DBTest2, PointInTimeRecoveryWithIOErrorWhileReadingWal) {
+  Options options = CurrentOptions();
+  DestroyAndReopen(options);
+  ASSERT_OK(Put("foo", "value0"));
+  Close();
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  bool should_inject_error = false;
+  SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::RecoverLogFiles:BeforeReadWal",
+      [&](void* /*arg*/) { should_inject_error = true; });
+  SyncPoint::GetInstance()->SetCallBack(
+      "LogReader::ReadMore:AfterReadFile", [&](void* arg) {
+        if (should_inject_error) {
+          ASSERT_NE(nullptr, arg);
+          *reinterpret_cast<Status*>(arg) = Status::IOError("Injected IOError");
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  options.avoid_flush_during_recovery = true;
+  options.wal_recovery_mode = WALRecoveryMode::kPointInTimeRecovery;
+  Status s = TryReopen(options);
+  ASSERT_TRUE(s.IsIOError());
+}
 }  // namespace ROCKSDB_NAMESPACE

 #ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
@@ -14,10 +14,19 @@

 namespace ROCKSDB_NAMESPACE {

+namespace {
+int64_t MaybeCurrentTime(Env* env) {
+  int64_t time = 1337346000;  // arbitrary fallback default
+  (void)env->GetCurrentTime(&time);
+  return time;
+}
+}  // namespace
+
 // Special Env used to delay background operations

 SpecialEnv::SpecialEnv(Env* base)
    : EnvWrapper(base),
+      maybe_starting_time_(MaybeCurrentTime(base)),
      rnd_(301),
      sleep_counter_(this),
      addon_time_(0),
@@ -399,20 +408,7 @@ Options DBTestBase::GetOptions(
        options.use_direct_reads = true;
        options.use_direct_io_for_flush_and_compaction = true;
        options.compaction_readahead_size = 2 * 1024 * 1024;
-  #if !defined(OS_MACOSX) && !defined(OS_WIN) && !defined(OS_SOLARIS) && \
-      !defined(OS_AIX) && !defined(OS_OPENBSD)
-        ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
-            "NewWritableFile:O_DIRECT", [&](void* arg) {
-              int* val = static_cast<int*>(arg);
-              *val &= ~O_DIRECT;
-            });
-        ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
-            "NewRandomAccessFile:O_DIRECT", [&](void* arg) {
-              int* val = static_cast<int*>(arg);
-              *val &= ~O_DIRECT;
-            });
-        ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
-#endif
+        test::SetupSyncPointsToMockDirectIO();
        break;
      }
 #endif  // ROCKSDB_LITE
@@ -502,10 +502,14 @@ class SpecialEnv : public EnvWrapper {

  virtual Status GetCurrentTime(int64_t* unix_time) override {
    Status s;
-    if (!time_elapse_only_sleep_) {
+    if (time_elapse_only_sleep_) {
+      *unix_time = maybe_starting_time_;
+    } else {
      s = target()->GetCurrentTime(unix_time);
    }
    if (s.ok()) {
+      // FIXME: addon_time_ sometimes used to mean seconds (here) and
+      // sometimes microseconds
      *unix_time += addon_time_.load();
    }
    return s;
@@ -531,6 +535,20 @@ class SpecialEnv : public EnvWrapper {
    return target()->DeleteFile(fname);
  }

+  void SetTimeElapseOnlySleep(Options* options) {
+    time_elapse_only_sleep_ = true;
+    no_slowdown_ = true;
+    // Need to disable stats dumping and persisting which also use
+    // RepeatableThread, which uses InstrumentedCondVar::TimedWaitInternal.
+    // With time_elapse_only_sleep_, this can hang on some platforms.
+    // TODO: why? investigate/fix
+    options->stats_dump_period_sec = 0;
+    options->stats_persist_period_sec = 0;
+  }
+
+  // Something to return when mocking current time
+  const int64_t maybe_starting_time_;
+
  Random rnd_;
  port::Mutex rnd_mutex_;  // Lock to pretect rnd_

@@ -647,6 +665,72 @@ class TestPutOperator : public MergeOperator {
  virtual const char* Name() const override { return "TestPutOperator"; }
 };

+// A wrapper around Cache that can easily be extended with instrumentation,
+// etc.
+class CacheWrapper : public Cache {
+ public:
+  explicit CacheWrapper(std::shared_ptr<Cache> target)
+      : target_(std::move(target)) {}
+
+  const char* Name() const override { return target_->Name(); }
+
+  Status Insert(const Slice& key, void* value, size_t charge,
+                void (*deleter)(const Slice& key, void* value),
+                Handle** handle = nullptr,
+                Priority priority = Priority::LOW) override {
+    return target_->Insert(key, value, charge, deleter, handle, priority);
+  }
+
+  Handle* Lookup(const Slice& key, Statistics* stats = nullptr) override {
+    return target_->Lookup(key, stats);
+  }
+
+  bool Ref(Handle* handle) override { return target_->Ref(handle); }
+
+  bool Release(Handle* handle, bool force_erase = false) override {
+    return target_->Release(handle, force_erase);
+  }
+
+  void* Value(Handle* handle) override { return target_->Value(handle); }
+
+  void Erase(const Slice& key) override { target_->Erase(key); }
+  uint64_t NewId() override { return target_->NewId(); }
+
+  void SetCapacity(size_t capacity) override { target_->SetCapacity(capacity); }
+
+  void SetStrictCapacityLimit(bool strict_capacity_limit) override {
+    target_->SetStrictCapacityLimit(strict_capacity_limit);
+  }
+
+  bool HasStrictCapacityLimit() const override {
+    return target_->HasStrictCapacityLimit();
+  }
+
+  size_t GetCapacity() const override { return target_->GetCapacity(); }
+
+  size_t GetUsage() const override { return target_->GetUsage(); }
+
+  size_t GetUsage(Handle* handle) const override {
+    return target_->GetUsage(handle);
+  }
+
+  size_t GetPinnedUsage() const override { return target_->GetPinnedUsage(); }
+
+  size_t GetCharge(Handle* handle) const override {
+    return target_->GetCharge(handle);
+  }
+
+  void ApplyToAllCacheEntries(void (*callback)(void*, size_t),
+                              bool thread_safe) override {
+    target_->ApplyToAllCacheEntries(callback, thread_safe);
+  }
+
+  void EraseUnRefEntries() override { target_->EraseUnRefEntries(); }
+
+ protected:
+  std::shared_ptr<Cache> target_;
+};
+
 class DBTestBase : public testing::Test {
 public:
  // Sequence of option configurations to try
@@ -1953,6 +1953,7 @@ TEST_F(DBTestUniversalCompaction2, BasicL0toL1) {
  ASSERT_GT(NumTableFilesAtLevel(6), 0);
 }

+#if defined(ENABLE_SINGLE_LEVEL_DTC)
 TEST_F(DBTestUniversalCompaction2, SingleLevel) {
  const int kNumKeys = 3000;
  const int kWindowSize = 100;
@@ -1991,6 +1992,7 @@ TEST_F(DBTestUniversalCompaction2, SingleLevel) {
  dbfull()->TEST_WaitForCompact();
  ASSERT_EQ(1, NumTableFilesAtLevel(0));
 }
+#endif  // ENABLE_SINGLE_LEVEL_DTC

 TEST_F(DBTestUniversalCompaction2, MultipleLevels) {
  const int kWindowSize = 100;
@@ -1422,8 +1422,11 @@ TEST_F(DBWALTest, RecoverFromCorruptedWALWithoutFlush) {
    delete iter;
    return data;
  };
-  for (auto& mode : wal_recovery_mode_string_map) {
-    options.wal_recovery_mode = mode.second;
+  for (auto& mode : {WALRecoveryMode::kTolerateCorruptedTailRecords,
+                     WALRecoveryMode::kAbsoluteConsistency,
+                     WALRecoveryMode::kPointInTimeRecovery,
+                     WALRecoveryMode::kSkipAnyCorruptedRecords}) {
+    options.wal_recovery_mode = mode;
    for (auto trunc : {true, false}) {
      for (int i = 0; i < 4; i++) {
        for (int j = jstart; j < jend; j++) {
@@ -26,22 +26,8 @@ class DBBasicTestWithTimestampBase : public DBTestBase {

 protected:
  static std::string Key1(uint64_t k) {
-    uint32_t x = 1;
-    const bool is_little_endian = (*reinterpret_cast<char*>(&x) != 0);
    std::string ret;
-    if (is_little_endian) {
-      ret.assign(reinterpret_cast<char*>(&k), sizeof(k));
-    } else {
-      ret.resize(sizeof(k));
-      ret[0] = k & 0xff;
-      ret[1] = (k >> 8) & 0xff;
-      ret[2] = (k >> 16) & 0xff;
-      ret[3] = (k >> 24) & 0xff;
-      ret[4] = (k >> 32) & 0xff;
-      ret[5] = (k >> 40) & 0xff;
-      ret[6] = (k >> 48) & 0xff;
-      ret[7] = (k >> 56) & 0xff;
-    }
+    PutFixed64(&ret, k);
    std::reverse(ret.begin(), ret.end());
    return ret;
  }
@@ -173,8 +159,6 @@ TEST_F(DBBasicTestWithTimestamp, SimpleForwardIterate) {
  const uint64_t kMaxKey = 1024;
  Options options = CurrentOptions();
  options.env = env_;
-  // TODO(yanqin) re-enable auto compaction
-  options.disable_auto_compactions = true;
  options.create_if_missing = true;
  const size_t kTimestampSize = Timestamp(0, 0).size();
  TestComparator test_cmp(kTimestampSize);
@@ -235,6 +219,56 @@ TEST_F(DBBasicTestWithTimestamp, SimpleForwardIterate) {
  Close();
 }

+TEST_F(DBBasicTestWithTimestamp, SimpleForwardIterateLowerTsBound) {
+  const int kNumKeysPerFile = 128;
+  const uint64_t kMaxKey = 1024;
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  options.comparator = &test_cmp;
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+  DestroyAndReopen(options);
+  const std::vector<std::string> write_timestamps = {Timestamp(1, 0),
+                                                     Timestamp(3, 0)};
+  const std::vector<std::string> read_timestamps = {Timestamp(2, 0),
+                                                    Timestamp(4, 0)};
+  const std::vector<std::string> read_timestamps_lb = {Timestamp(1, 0),
+                                                       Timestamp(1, 0)};
+  for (size_t i = 0; i < write_timestamps.size(); ++i) {
+    WriteOptions write_opts;
+    Slice write_ts = write_timestamps[i];
+    write_opts.timestamp = &write_ts;
+    for (uint64_t key = 0; key <= kMaxKey; ++key) {
+      Status s = db_->Put(write_opts, Key1(key), "value" + std::to_string(i));
+      ASSERT_OK(s);
+    }
+  }
+  for (size_t i = 0; i < read_timestamps.size(); ++i) {
+    ReadOptions read_opts;
+    Slice read_ts = read_timestamps[i];
+    Slice read_ts_lb = read_timestamps_lb[i];
+    read_opts.timestamp = &read_ts;
+    read_opts.iter_start_ts = &read_ts_lb;
+    std::unique_ptr<Iterator> it(db_->NewIterator(read_opts));
+    int count = 0;
+    uint64_t key = 0;
+    for (it->Seek(Key1(0)), key = 0; it->Valid(); it->Next(), ++count, ++key) {
+      CheckIterUserEntry(it.get(), Key1(key), "value" + std::to_string(i),
+                         write_timestamps[i]);
+      if (i > 0) {
+        it->Next();
+        CheckIterUserEntry(it.get(), Key1(key), "value" + std::to_string(i - 1),
+                           write_timestamps[i - 1]);
+      }
+    }
+    size_t expected_count = kMaxKey + 1;
+    ASSERT_EQ(expected_count, count);
+  }
+  Close();
+}
+
 TEST_F(DBBasicTestWithTimestamp, ForwardIterateStartSeqnum) {
  const int kNumKeysPerFile = 128;
  const uint64_t kMaxKey = 0xffffffffffffffff;
@@ -242,7 +276,9 @@ TEST_F(DBBasicTestWithTimestamp, ForwardIterateStartSeqnum) {
  Options options = CurrentOptions();
  options.env = env_;
  options.create_if_missing = true;
-  // TODO(yanqin) re-enable auto compaction
+  // Need to disable compaction to bottommost level when sequence number will be
+  // zeroed out, causing the verification of sequence number to fail in this
+  // test.
  options.disable_auto_compactions = true;
  const size_t kTimestampSize = Timestamp(0, 0).size();
  TestComparator test_cmp(kTimestampSize);
@@ -300,8 +336,6 @@ TEST_F(DBBasicTestWithTimestamp, ReseekToTargetTimestamp) {
  constexpr size_t kNumKeys = 16;
  options.max_sequential_skip_in_iterations = kNumKeys / 2;
  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
-  // TODO(yanqin) re-enable auto compaction
-  options.disable_auto_compactions = true;
  const size_t kTimestampSize = Timestamp(0, 0).size();
  TestComparator test_cmp(kTimestampSize);
  options.comparator = &test_cmp;
@@ -337,8 +371,6 @@ TEST_F(DBBasicTestWithTimestamp, ReseekToNextUserKey) {
  constexpr size_t kNumKeys = 16;
  options.max_sequential_skip_in_iterations = kNumKeys / 2;
  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
-  // TODO(yanqin) re-enable auto compaction
-  options.disable_auto_compactions = true;
  const size_t kTimestampSize = Timestamp(0, 0).size();
  TestComparator test_cmp(kTimestampSize);
  options.comparator = &test_cmp;
@@ -417,10 +449,70 @@ TEST_F(DBBasicTestWithTimestamp, MaxKeysSkipped) {
  Close();
 }

+// Create two L0, and compact them to a new L1. In this test, L1 is L_bottom.
+// Two L0s:
+//       f1                                  f2
+// <a, 1, kTypeValue>    <a, 3, kTypeDeletionWithTimestamp>...<b, 2, kTypeValue>
+// Since f2.smallest < f1.largest < f2.largest
+// f1 and f2 will be the inputs of a real compaction instead of trivial move.
+TEST_F(DBBasicTestWithTimestamp, CompactDeletionWithTimestampMarkerToBottom) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  options.comparator = &test_cmp;
+  options.num_levels = 2;
+  options.level0_file_num_compaction_trigger = 2;
+  DestroyAndReopen(options);
+  WriteOptions write_opts;
+  std::string ts_str = Timestamp(1, 0);
+  Slice ts = ts_str;
+  write_opts.timestamp = &ts;
+  ASSERT_OK(db_->Put(write_opts, "a", "value0"));
+  ASSERT_OK(Flush());
+
+  ts_str = Timestamp(2, 0);
+  ts = ts_str;
+  write_opts.timestamp = &ts;
+  ASSERT_OK(db_->Put(write_opts, "b", "value0"));
+  ts_str = Timestamp(3, 0);
+  ts = ts_str;
+  write_opts.timestamp = &ts;
+  ASSERT_OK(db_->Delete(write_opts, "a"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  ReadOptions read_opts;
+  ts_str = Timestamp(1, 0);
+  ts = ts_str;
+  read_opts.timestamp = &ts;
+  std::string value;
+  Status s = db_->Get(read_opts, "a", &value);
+  ASSERT_OK(s);
+  ASSERT_EQ("value0", value);
+
+  ts_str = Timestamp(3, 0);
+  ts = ts_str;
+  read_opts.timestamp = &ts;
+  s = db_->Get(read_opts, "a", &value);
+  ASSERT_TRUE(s.IsNotFound());
+
+  // Time-travel to the past before deletion
+  ts_str = Timestamp(2, 0);
+  ts = ts_str;
+  read_opts.timestamp = &ts;
+  s = db_->Get(read_opts, "a", &value);
+  ASSERT_OK(s);
+  ASSERT_EQ("value0", value);
+  Close();
+}
+
 class DBBasicTestWithTimestampCompressionSettings
    : public DBBasicTestWithTimestampBase,
-      public testing::WithParamInterface<std::tuple<
-          std::shared_ptr<const FilterPolicy>, CompressionType, uint32_t>> {
+      public testing::WithParamInterface<
+          std::tuple<std::shared_ptr<const FilterPolicy>, CompressionType,
+                     uint32_t, uint32_t>> {
 public:
  DBBasicTestWithTimestampCompressionSettings()
      : DBBasicTestWithTimestampBase(
@@ -460,6 +552,7 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGet) {
  if (comp_type == kZSTD) {
    options.compression_opts.zstd_max_train_bytes = std::get<2>(GetParam());
  }
+  options.compression_opts.parallel_threads = std::get<3>(GetParam());
  options.target_file_size_base = 1 << 26;  // 64MB
  DestroyAndReopen(options);
  CreateAndReopenWithCF({"pikachu"}, options);
@@ -502,6 +595,104 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGet) {
  Close();
 }

+TEST_P(DBBasicTestWithTimestampCompressionSettings, PutDeleteGet) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  options.comparator = &test_cmp;
+  const int kNumKeysPerFile = 1024;
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy = std::get<0>(GetParam());
+  bbto.whole_key_filtering = true;
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+
+  const CompressionType comp_type = std::get<1>(GetParam());
+#if LZ4_VERSION_NUMBER < 10400  // r124+
+  if (comp_type == kLZ4Compression || comp_type == kLZ4HCCompression) {
+    return;
+  }
+#endif  // LZ4_VERSION_NUMBER >= 10400
+  if (!ZSTD_Supported() && comp_type == kZSTD) {
+    return;
+  }
+  if (!Zlib_Supported() && comp_type == kZlibCompression) {
+    return;
+  }
+
+  options.compression = comp_type;
+  options.compression_opts.max_dict_bytes = std::get<2>(GetParam());
+  if (comp_type == kZSTD) {
+    options.compression_opts.zstd_max_train_bytes = std::get<2>(GetParam());
+  }
+  options.compression_opts.parallel_threads = std::get<3>(GetParam());
+  options.target_file_size_base = 1 << 26;  // 64MB
+
+  DestroyAndReopen(options);
+
+  const size_t kNumL0Files =
+      static_cast<size_t>(Options().level0_file_num_compaction_trigger);
+  {
+    // Generate enough L0 files with ts=1 to trigger compaction to L1
+    std::string ts_str = Timestamp(1, 0);
+    Slice ts = ts_str;
+    WriteOptions wopts;
+    wopts.timestamp = &ts;
+    for (size_t i = 0; i != kNumL0Files; ++i) {
+      for (int j = 0; j != kNumKeysPerFile; ++j) {
+        ASSERT_OK(db_->Put(wopts, Key1(j), "value" + std::to_string(i)));
+      }
+      ASSERT_OK(db_->Flush(FlushOptions()));
+    }
+    ASSERT_OK(dbfull()->TEST_WaitForCompact());
+    // Generate another L0 at ts=3
+    ts_str = Timestamp(3, 0);
+    ts = ts_str;
+    wopts.timestamp = &ts;
+    for (int i = 0; i != kNumKeysPerFile; ++i) {
+      std::string key_str = Key1(i);
+      Slice key(key_str);
+      if ((i % 3) == 0) {
+        ASSERT_OK(db_->Delete(wopts, key));
+      } else {
+        ASSERT_OK(db_->Put(wopts, key, "new_value"));
+      }
+    }
+    ASSERT_OK(db_->Flush(FlushOptions()));
+    // Populate memtable at ts=5
+    ts_str = Timestamp(5, 0);
+    ts = ts_str;
+    wopts.timestamp = &ts;
+    for (int i = 0; i != kNumKeysPerFile; ++i) {
+      std::string key_str = Key1(i);
+      Slice key(key_str);
+      if ((i % 3) == 1) {
+        ASSERT_OK(db_->Delete(wopts, key));
+      } else if ((i % 3) == 2) {
+        ASSERT_OK(db_->Put(wopts, key, "new_value_2"));
+      }
+    }
+  }
+  {
+    std::string ts_str = Timestamp(6, 0);
+    Slice ts = ts_str;
+    ReadOptions ropts;
+    ropts.timestamp = &ts;
+    for (uint64_t i = 0; i != static_cast<uint64_t>(kNumKeysPerFile); ++i) {
+      std::string value;
+      Status s = db_->Get(ropts, Key1(i), &value);
+      if ((i % 3) == 2) {
+        ASSERT_OK(s);
+        ASSERT_EQ("new_value_2", value);
+      } else {
+        ASSERT_TRUE(s.IsNotFound());
+      }
+    }
+  }
+}
+
 #ifndef ROCKSDB_LITE
 // A class which remembers the name of each flushed file.
 class FlushedFileCollector : public EventListener {
@@ -572,6 +763,7 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
  if (comp_type == kZSTD) {
    options.compression_opts.zstd_max_train_bytes = std::get<2>(GetParam());
  }
+  options.compression_opts.parallel_threads = std::get<3>(GetParam());
  DestroyAndReopen(options);
  CreateAndReopenWithCF({"pikachu"}, options);

@@ -580,8 +772,8 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
  std::vector<std::string> write_ts_list;
  std::vector<std::string> read_ts_list;

-  const auto& verify_record_func = [&](size_t i, size_t k,
-                                       ColumnFamilyHandle* cfh) {
+  const auto& verify_records_func = [&](size_t i, size_t begin, size_t end,
+                                        ColumnFamilyHandle* cfh) {
    std::string value;
    std::string timestamp;

@@ -591,9 +783,11 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
    std::string expected_timestamp =
        std::string(write_ts_list[i].data(), write_ts_list[i].size());

-    ASSERT_OK(db_->Get(ropts, cfh, Key1(k), &value, &timestamp));
-    ASSERT_EQ("value_" + std::to_string(k) + "_" + std::to_string(i), value);
-    ASSERT_EQ(expected_timestamp, timestamp);
+    for (size_t j = begin; j <= end; ++j) {
+      ASSERT_OK(db_->Get(ropts, cfh, Key1(j), &value, &timestamp));
+      ASSERT_EQ("value_" + std::to_string(j) + "_" + std::to_string(i), value);
+      ASSERT_EQ(expected_timestamp, timestamp);
+    }
  };

  for (size_t i = 0; i != kNumTimestamps; ++i) {
@@ -609,9 +803,7 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
                      "value_" + std::to_string(j) + "_" + std::to_string(i),
                      wopts));
        if (j == kSplitPosBase + i || j == kNumKeysPerTimestamp - 1) {
-          for (size_t k = memtable_get_start; k <= j; ++k) {
-            verify_record_func(i, k, handles_[cf]);
-          }
+          verify_records_func(i, memtable_get_start, j, handles_[cf]);
          memtable_get_start = j + 1;

          // flush all keys with the same timestamp to two sst files, split at
@@ -619,9 +811,9 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
          // higherlevel[0].largest.userkey
          ASSERT_OK(Flush(cf));

-          // compact files (2 at each level) to a lower level such that all keys
-          // with the same timestamp is at one level, with newer versions at
-          // higher levels.
+          // compact files (2 at each level) to a lower level such that all
+          // keys with the same timestamp is at one level, with newer versions
+          // at higher levels.
          CompactionOptions compact_opt;
          compact_opt.compression = kNoCompression;
          db_->CompactFiles(compact_opt, handles_[cf],
@@ -641,15 +833,153 @@ TEST_P(DBBasicTestWithTimestampCompressionSettings, PutAndGetWithCompaction) {
                                     write_ts_list[i].size());
      for (int cf = 0; cf != static_cast<int>(num_cfs); ++cf) {
        ColumnFamilyHandle* cfh = handles_[cf];
-        for (size_t j = 0; j != kNumKeysPerTimestamp; ++j) {
-          verify_record_func(i, j, cfh);
-        }
+        verify_records_func(i, 0, kNumKeysPerTimestamp - 1, cfh);
      }
    }
  };
  verify_db_func();
  Close();
 }
+
+TEST_F(DBBasicTestWithTimestamp, BatchWriteAndMultiGet) {
+  const int kNumKeysPerFile = 8192;
+  const size_t kNumTimestamps = 2;
+  const size_t kNumKeysPerTimestamp = (kNumKeysPerFile - 1) / kNumTimestamps;
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  options.env = env_;
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+
+  size_t ts_sz = Timestamp(0, 0).size();
+  TestComparator test_cmp(ts_sz);
+  options.comparator = &test_cmp;
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy.reset(NewBloomFilterPolicy(
+      10 /*bits_per_key*/, false /*use_block_based_builder*/));
+  bbto.whole_key_filtering = true;
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  DestroyAndReopen(options);
+  CreateAndReopenWithCF({"pikachu"}, options);
+  size_t num_cfs = handles_.size();
+  ASSERT_EQ(2, num_cfs);
+  std::vector<std::string> write_ts_list;
+  std::vector<std::string> read_ts_list;
+
+  const auto& verify_records_func = [&](size_t i, ColumnFamilyHandle* cfh) {
+    std::vector<Slice> keys;
+    std::vector<std::string> key_vals;
+    std::vector<std::string> values;
+    std::vector<std::string> timestamps;
+
+    for (size_t j = 0; j != kNumKeysPerTimestamp; ++j) {
+      key_vals.push_back(Key1(j));
+    }
+    for (size_t j = 0; j != kNumKeysPerTimestamp; ++j) {
+      keys.push_back(key_vals[j]);
+    }
+
+    ReadOptions ropts;
+    const Slice read_ts = read_ts_list[i];
+    ropts.timestamp = &read_ts;
+    std::string expected_timestamp(write_ts_list[i].data(),
+                                   write_ts_list[i].size());
+
+    std::vector<ColumnFamilyHandle*> cfhs(keys.size(), cfh);
+    std::vector<Status> statuses =
+        db_->MultiGet(ropts, cfhs, keys, &values, &timestamps);
+    for (size_t j = 0; j != kNumKeysPerTimestamp; ++j) {
+      ASSERT_OK(statuses[j]);
+      ASSERT_EQ("value_" + std::to_string(j) + "_" + std::to_string(i),
+                values[j]);
+      ASSERT_EQ(expected_timestamp, timestamps[j]);
+    }
+  };
+
+  for (size_t i = 0; i != kNumTimestamps; ++i) {
+    write_ts_list.push_back(Timestamp(i * 2, 0));
+    read_ts_list.push_back(Timestamp(1 + i * 2, 0));
+    const Slice& write_ts = write_ts_list.back();
+    for (int cf = 0; cf != static_cast<int>(num_cfs); ++cf) {
+      WriteOptions wopts;
+      WriteBatch batch(0, 0, ts_sz);
+      for (size_t j = 0; j != kNumKeysPerTimestamp; ++j) {
+        ASSERT_OK(
+            batch.Put(handles_[cf], Key1(j),
+                      "value_" + std::to_string(j) + "_" + std::to_string(i)));
+      }
+      batch.AssignTimestamp(write_ts);
+      ASSERT_OK(db_->Write(wopts, &batch));
+
+      verify_records_func(i, handles_[cf]);
+
+      ASSERT_OK(Flush(cf));
+    }
+  }
+
+  const auto& verify_db_func = [&]() {
+    for (size_t i = 0; i != kNumTimestamps; ++i) {
+      ReadOptions ropts;
+      const Slice read_ts = read_ts_list[i];
+      ropts.timestamp = &read_ts;
+      for (int cf = 0; cf != static_cast<int>(num_cfs); ++cf) {
+        ColumnFamilyHandle* cfh = handles_[cf];
+        verify_records_func(i, cfh);
+      }
+    }
+  };
+  verify_db_func();
+  Close();
+}
+
+TEST_F(DBBasicTestWithTimestamp, MultiGetNoReturnTs) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  options.comparator = &test_cmp;
+  DestroyAndReopen(options);
+  WriteOptions write_opts;
+  std::string ts_str = Timestamp(1, 0);
+  Slice ts = ts_str;
+  write_opts.timestamp = &ts;
+  ASSERT_OK(db_->Put(write_opts, "foo", "value"));
+  ASSERT_OK(db_->Put(write_opts, "bar", "value"));
+  ASSERT_OK(db_->Put(write_opts, "fooxxxxxxxxxxxxxxxx", "value"));
+  ASSERT_OK(db_->Put(write_opts, "barxxxxxxxxxxxxxxxx", "value"));
+  ColumnFamilyHandle* cfh = dbfull()->DefaultColumnFamily();
+  ts_str = Timestamp(2, 0);
+  ts = ts_str;
+  ReadOptions read_opts;
+  read_opts.timestamp = &ts;
+  {
+    ColumnFamilyHandle* column_families[] = {cfh, cfh};
+    Slice keys[] = {"foo", "bar"};
+    PinnableSlice values[] = {PinnableSlice(), PinnableSlice()};
+    Status statuses[] = {Status::OK(), Status::OK()};
+    dbfull()->MultiGet(read_opts, /*num_keys=*/2, &column_families[0], &keys[0],
+                       &values[0], &statuses[0], /*sorted_input=*/false);
+    for (const auto& s : statuses) {
+      ASSERT_OK(s);
+    }
+  }
+  {
+    ColumnFamilyHandle* column_families[] = {cfh, cfh, cfh, cfh};
+    // Make user keys longer than configured timestamp size (16 bytes) to
+    // verify RocksDB does not use the trailing bytes 'x' as timestamp.
+    Slice keys[] = {"fooxxxxxxxxxxxxxxxx", "barxxxxxxxxxxxxxxxx", "foo", "bar"};
+    PinnableSlice values[] = {PinnableSlice(), PinnableSlice(), PinnableSlice(),
+                              PinnableSlice()};
+    Status statuses[] = {Status::OK(), Status::OK(), Status::OK(),
+                         Status::OK()};
+    dbfull()->MultiGet(read_opts, /*num_keys=*/4, &column_families[0], &keys[0],
+                       &values[0], &statuses[0], /*sorted_input=*/false);
+    for (const auto& s : statuses) {
+      ASSERT_OK(s);
+    }
+  }
+  Close();
+}
+
 #endif  // !ROCKSDB_LITE

 INSTANTIATE_TEST_CASE_P(
@@ -660,7 +990,7 @@ INSTANTIATE_TEST_CASE_P(
                              NewBloomFilterPolicy(10, false))),
        ::testing::Values(kNoCompression, kZlibCompression, kLZ4Compression,
                          kLZ4HCCompression, kZSTD),
-        ::testing::Values(0, 1 << 14)));
+        ::testing::Values(0, 1 << 14), ::testing::Values(1, 4)));

 class DBBasicTestWithTimestampPrefixSeek
    : public DBBasicTestWithTimestampBase,
@@ -678,8 +1008,6 @@ TEST_P(DBBasicTestWithTimestampPrefixSeek, ForwardIterateWithPrefix) {
  Options options = CurrentOptions();
  options.env = env_;
  options.create_if_missing = true;
-  // TODO(yanqin): re-enable auto compactions
-  options.disable_auto_compactions = true;
  const size_t kTimestampSize = Timestamp(0, 0).size();
  TestComparator test_cmp(kTimestampSize);
  options.comparator = &test_cmp;
@@ -699,15 +1027,10 @@ TEST_P(DBBasicTestWithTimestampPrefixSeek, ForwardIterateWithPrefix) {
    for (size_t i = 0; i != write_ts_list.size(); ++i) {
      Slice write_ts = write_ts_list[i];
      write_opts.timestamp = &write_ts;
-      uint64_t key = kMinKey;
-      do {
+      for (uint64_t key = kMaxKey; key >= kMinKey; --key) {
        Status s = db_->Put(write_opts, Key1(key), "value" + std::to_string(i));
        ASSERT_OK(s);
-        if (key == kMaxKey) {
-          break;
-        }
-        ++key;
-      } while (true);
+      }
    }
  }
  const std::vector<std::string> read_ts_list = {Timestamp(5, 0xffffffff),
@@ -791,6 +1114,90 @@ INSTANTIATE_TEST_CASE_P(
                                                   false))),
        ::testing::Bool()));

+class DBBasicTestWithTsIterTombstones
+    : public DBBasicTestWithTimestampBase,
+      public testing::WithParamInterface<
+          std::tuple<std::shared_ptr<const SliceTransform>,
+                     std::shared_ptr<const FilterPolicy>, int>> {
+ public:
+  DBBasicTestWithTsIterTombstones()
+      : DBBasicTestWithTimestampBase("/db_basic_ts_iter_tombstones") {}
+};
+
+TEST_P(DBBasicTestWithTsIterTombstones, ForwardIterDelete) {
+  constexpr size_t kNumKeysPerFile = 128;
+  Options options = CurrentOptions();
+  options.env = env_;
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  options.comparator = &test_cmp;
+  options.prefix_extractor = std::get<0>(GetParam());
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+  BlockBasedTableOptions bbto;
+  bbto.filter_policy = std::get<1>(GetParam());
+  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
+  options.num_levels = std::get<2>(GetParam());
+  DestroyAndReopen(options);
+  std::vector<std::string> write_ts_strs = {Timestamp(2, 0), Timestamp(4, 0)};
+  constexpr uint64_t kMaxKey = 0xffffffffffffffff;
+  constexpr uint64_t kMinKey = 0xfffffffffffff000;
+  // Insert kMinKey...kMaxKey
+  uint64_t key = kMinKey;
+  WriteOptions write_opts;
+  Slice ts = write_ts_strs[0];
+  write_opts.timestamp = &ts;
+  do {
+    Status s = db_->Put(write_opts, Key1(key), "value" + std::to_string(key));
+    ASSERT_OK(s);
+    if (kMaxKey == key) {
+      break;
+    }
+    ++key;
+  } while (true);
+  // Delete them all
+  ts = write_ts_strs[1];
+  write_opts.timestamp = &ts;
+  for (key = kMaxKey; key >= kMinKey; --key) {
+    Status s;
+    if (0 != (key % 2)) {
+      s = db_->Put(write_opts, Key1(key), "value1" + std::to_string(key));
+    } else {
+      s = db_->Delete(write_opts, Key1(key));
+    }
+    ASSERT_OK(s);
+  }
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  {
+    std::string read_ts = Timestamp(4, 0);
+    ts = read_ts;
+    ReadOptions read_opts;
+    read_opts.total_order_seek = true;
+    read_opts.timestamp = &ts;
+    std::unique_ptr<Iterator> iter(db_->NewIterator(read_opts));
+    size_t count = 0;
+    key = kMinKey + 1;
+    for (iter->SeekToFirst(); iter->Valid(); iter->Next(), ++count, key += 2) {
+      ASSERT_EQ(Key1(key), iter->key());
+      ASSERT_EQ("value1" + std::to_string(key), iter->value());
+    }
+    ASSERT_EQ((kMaxKey - kMinKey + 1) / 2, count);
+  }
+  Close();
+}
+
+INSTANTIATE_TEST_CASE_P(
+    Timestamp, DBBasicTestWithTsIterTombstones,
+    ::testing::Combine(
+        ::testing::Values(
+            std::shared_ptr<const SliceTransform>(NewFixedPrefixTransform(7)),
+            std::shared_ptr<const SliceTransform>(NewFixedPrefixTransform(8))),
+        ::testing::Values(std::shared_ptr<const FilterPolicy>(nullptr),
+                          std::shared_ptr<const FilterPolicy>(
+                              NewBloomFilterPolicy(10, false)),
+                          std::shared_ptr<const FilterPolicy>(
+                              NewBloomFilterPolicy(20, false))),
+        ::testing::Values(2, 6)));
+
 }  // namespace ROCKSDB_NAMESPACE

 #ifdef ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS
@@ -0,0 +1,119 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "db/compaction/compaction.h"
+#include "db/db_test_util.h"
+#include "port/stack_trace.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+namespace {
+std::string Key1(uint64_t key) {
+  std::string ret;
+  PutFixed64(&ret, key);
+  std::reverse(ret.begin(), ret.end());
+  return ret;
+}
+
+std::string Timestamp(uint64_t ts) {
+  std::string ret;
+  PutFixed64(&ret, ts);
+  return ret;
+}
+}  // anonymous namespace
+
+class TimestampCompatibleCompactionTest : public DBTestBase {
+ public:
+  TimestampCompatibleCompactionTest()
+      : DBTestBase("/ts_compatible_compaction_test") {}
+
+  std::string Get(const std::string& key, uint64_t ts) {
+    ReadOptions read_opts;
+    std::string ts_str = Timestamp(ts);
+    Slice ts_slice = ts_str;
+    read_opts.timestamp = &ts_slice;
+    std::string value;
+    Status s = db_->Get(read_opts, key, &value);
+    if (s.IsNotFound()) {
+      value.assign("NOT_FOUND");
+    } else if (!s.ok()) {
+      value.assign(s.ToString());
+    }
+    return value;
+  }
+};
+
+TEST_F(TimestampCompatibleCompactionTest, UserKeyCrossFileBoundary) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.compaction_style = kCompactionStyleLevel;
+  options.comparator = test::ComparatorWithU64Ts();
+  options.level0_file_num_compaction_trigger = 3;
+  constexpr size_t kNumKeysPerFile = 101;
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+  DestroyAndReopen(options);
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "LevelCompactionPicker::PickCompaction:Return", [&](void* arg) {
+        const auto* compaction = reinterpret_cast<Compaction*>(arg);
+        ASSERT_NE(nullptr, compaction);
+        ASSERT_EQ(0, compaction->start_level());
+        ASSERT_EQ(1, compaction->num_input_levels());
+        // Check that all 3 L0 ssts are picked for level compaction.
+        ASSERT_EQ(3, compaction->num_input_files(0));
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+  // Write a L0 with keys 0, 1, ..., 99 with ts from 100 to 199.
+  uint64_t ts = 100;
+  uint64_t key = 0;
+  WriteOptions write_opts;
+  for (; key < kNumKeysPerFile - 1; ++key, ++ts) {
+    std::string ts_str = Timestamp(ts);
+    Slice ts_slice = ts_str;
+    write_opts.timestamp = &ts_slice;
+    ASSERT_OK(db_->Put(write_opts, Key1(key), "foo_" + std::to_string(key)));
+  }
+  // Write another L0 with keys 99 with newer ts.
+  ASSERT_OK(Flush());
+  uint64_t saved_read_ts1 = ts++;
+  key = 99;
+  for (int i = 0; i < 4; ++i, ++ts) {
+    std::string ts_str = Timestamp(ts);
+    Slice ts_slice = ts_str;
+    write_opts.timestamp = &ts_slice;
+    ASSERT_OK(db_->Put(write_opts, Key1(key), "bar_" + std::to_string(key)));
+  }
+  ASSERT_OK(Flush());
+  uint64_t saved_read_ts2 = ts++;
+  // Write another L0 with keys 99, 100, 101, ..., 150
+  for (; key <= 150; ++key, ++ts) {
+    std::string ts_str = Timestamp(ts);
+    Slice ts_slice = ts_str;
+    write_opts.timestamp = &ts_slice;
+    ASSERT_OK(db_->Put(write_opts, Key1(key), "foo1_" + std::to_string(key)));
+  }
+  ASSERT_OK(Flush());
+  // Wait for compaction to finish
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  uint64_t read_ts = ts;
+  ASSERT_EQ("foo_99", Get(Key1(99), saved_read_ts1));
+  ASSERT_EQ("bar_99", Get(Key1(99), saved_read_ts2));
+  ASSERT_EQ("foo1_99", Get(Key1(99), read_ts));
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->DisableProcessing();
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
@@ -23,7 +23,7 @@ namespace ROCKSDB_NAMESPACE {
 // and the value type is embedded as the low 8 bits in the sequence
 // number in internal keys, we need to use the highest-numbered
 // ValueType, not the lowest).
-const ValueType kValueTypeForSeek = kTypeBlobIndex;
+const ValueType kValueTypeForSeek = kTypeDeletionWithTimestamp;
 const ValueType kValueTypeForSeekForPrev = kTypeDeletion;

 uint64_t PackSequenceAndType(uint64_t seq, ValueType t) {
@@ -69,7 +69,8 @@ enum ValueType : unsigned char {
  // generated by WriteUnprepared write policy is not mistakenly read by
  // another.
  kTypeBeginUnprepareXID = 0x13,  // WAL only.
-  kMaxValue = 0x7F                // Not used for storing records.
+  kTypeDeletionWithTimestamp = 0x14,
+  kMaxValue = 0x7F  // Not used for storing records.
 };

 // Defined in dbformat.cc
@@ -79,7 +80,8 @@ extern const ValueType kValueTypeForSeekForPrev;
 // Checks whether a type is an inline value type
 // (i.e. a type used in memtable skiplist and sst file datablock).
 inline bool IsValueType(ValueType t) {
-  return t <= kTypeMerge || t == kTypeSingleDeletion || t == kTypeBlobIndex;
+  return t <= kTypeMerge || t == kTypeSingleDeletion || t == kTypeBlobIndex ||
+         kTypeDeletionWithTimestamp == t;
 }

 // Checks whether a type is from user operation
@@ -51,9 +51,19 @@ std::map<std::tuple<BackgroundErrorReason, Status::Code, Status::SubCode, bool>,
                         Status::Code::kIOError, Status::SubCode::kNoSpace,
                         false),
         Status::Severity::kHardError},
+        // Errors during MANIFEST write
+        {std::make_tuple(BackgroundErrorReason::kManifestWrite,
+                         Status::Code::kIOError, Status::SubCode::kNoSpace,
+                         true),
+         Status::Severity::kHardError},
+        {std::make_tuple(BackgroundErrorReason::kManifestWrite,
+                         Status::Code::kIOError, Status::SubCode::kNoSpace,
+                         false),
+         Status::Severity::kHardError},
 };

-std::map<std::tuple<BackgroundErrorReason, Status::Code, bool>, Status::Severity>
+std::map<std::tuple<BackgroundErrorReason, Status::Code, bool>,
+         Status::Severity>
    DefaultErrorSeverityMap = {
        // Errors during BG compaction
        {std::make_tuple(BackgroundErrorReason::kCompaction,
@@ -75,11 +85,11 @@ std::map<std::tuple<BackgroundErrorReason, Status::Code, bool>, Status::Severity
        {std::make_tuple(BackgroundErrorReason::kFlush,
                         Status::Code::kCorruption, false),
         Status::Severity::kNoError},
-        {std::make_tuple(BackgroundErrorReason::kFlush,
-                         Status::Code::kIOError, true),
+        {std::make_tuple(BackgroundErrorReason::kFlush, Status::Code::kIOError,
+                         true),
         Status::Severity::kFatalError},
-        {std::make_tuple(BackgroundErrorReason::kFlush,
-                         Status::Code::kIOError, false),
+        {std::make_tuple(BackgroundErrorReason::kFlush, Status::Code::kIOError,
+                         false),
         Status::Severity::kNoError},
        // Errors during Write
        {std::make_tuple(BackgroundErrorReason::kWriteCallback,
@@ -94,30 +104,36 @@ std::map<std::tuple<BackgroundErrorReason, Status::Code, bool>, Status::Severity
        {std::make_tuple(BackgroundErrorReason::kWriteCallback,
                         Status::Code::kIOError, false),
         Status::Severity::kNoError},
+        {std::make_tuple(BackgroundErrorReason::kManifestWrite,
+                         Status::Code::kIOError, true),
+         Status::Severity::kFatalError},
+        {std::make_tuple(BackgroundErrorReason::kManifestWrite,
+                         Status::Code::kIOError, false),
+         Status::Severity::kFatalError},
 };

 std::map<std::tuple<BackgroundErrorReason, bool>, Status::Severity>
    DefaultReasonMap = {
        // Errors during BG compaction
        {std::make_tuple(BackgroundErrorReason::kCompaction, true),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
        {std::make_tuple(BackgroundErrorReason::kCompaction, false),
-          Status::Severity::kNoError},
+         Status::Severity::kNoError},
        // Errors during BG flush
        {std::make_tuple(BackgroundErrorReason::kFlush, true),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
        {std::make_tuple(BackgroundErrorReason::kFlush, false),
-          Status::Severity::kNoError},
+         Status::Severity::kNoError},
        // Errors during Write
        {std::make_tuple(BackgroundErrorReason::kWriteCallback, true),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
        {std::make_tuple(BackgroundErrorReason::kWriteCallback, false),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
        // Errors during Memtable update
        {std::make_tuple(BackgroundErrorReason::kMemTable, true),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
        {std::make_tuple(BackgroundErrorReason::kMemTable, false),
-          Status::Severity::kFatalError},
+         Status::Severity::kFatalError},
 };

 void ErrorHandler::CancelErrorRecovery() {
@@ -238,6 +254,50 @@ Status ErrorHandler::SetBGError(const Status& bg_err, BackgroundErrorReason reas
  return bg_error_;
 }

+Status ErrorHandler::SetBGError(const IOStatus& bg_io_err,
+                                BackgroundErrorReason reason) {
+  db_mutex_->AssertHeld();
+  if (bg_io_err.ok()) {
+    return Status::OK();
+  }
+  if (recovery_in_prog_ && recovery_error_.ok()) {
+    recovery_error_ = bg_io_err;
+  }
+  if (BackgroundErrorReason::kManifestWrite == reason) {
+    // Always returns ok
+    db_->DisableFileDeletionsWithLock();
+  }
+  Status new_bg_io_err = bg_io_err;
+  Status s;
+  if (bg_io_err.GetDataLoss()) {
+    // FIrst, data loss is treated as unrecoverable error. So it can directly
+    // overwrite any existing bg_error_.
+    bool auto_recovery = false;
+    Status bg_err(new_bg_io_err, Status::Severity::kUnrecoverableError);
+    bg_error_ = bg_err;
+    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason, &s,
+                                          db_mutex_, &auto_recovery);
+    return bg_error_;
+  } else if (bg_io_err.GetRetryable()) {
+    // Second, check if the error is a retryable IO error or not. if it is
+    // retryable error and its severity is higher than bg_error_, overwrite
+    // the bg_error_ with new error.
+    // In current stage, treat retryable error as HardError. No automatic
+    // recovery.
+    bool auto_recovery = false;
+    Status bg_err(new_bg_io_err, Status::Severity::kHardError);
+    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason, &s,
+                                          db_mutex_, &auto_recovery);
+    if (bg_err.severity() > bg_error_.severity()) {
+      bg_error_ = bg_err;
+    }
+    return bg_error_;
+  } else {
+    s = SetBGError(new_bg_io_err, reason);
+  }
+  return s;
+}
+
 Status ErrorHandler::OverrideNoSpaceError(Status bg_error,
                                          bool* auto_recovery) {
 #ifndef ROCKSDB_LITE
@@ -6,6 +6,7 @@

 #include "monitoring/instrumented_mutex.h"
 #include "options/db_options.h"
+#include "rocksdb/io_status.h"
 #include "rocksdb/listener.h"
 #include "rocksdb/status.h"

@@ -34,6 +35,8 @@ class ErrorHandler {

   Status SetBGError(const Status& bg_err, BackgroundErrorReason reason);

+   Status SetBGError(const IOStatus& bg_io_err, BackgroundErrorReason reason);
+
   Status GetBGError() { return bg_error_; }

   Status GetRecoveryError() { return recovery_error_; }
@@ -44,7 +44,7 @@ class DBErrorHandlingFSTest : public DBTestBase {
 class DBErrorHandlingFS : public FileSystemWrapper {
 public:
  DBErrorHandlingFS()
-      : FileSystemWrapper(FileSystem::Default().get()),
+      : FileSystemWrapper(FileSystem::Default()),
        trig_no_space(false),
        trig_io_error(false) {}

@@ -150,12 +150,13 @@ class ErrorHandlerFSListener : public EventListener {
 };

 TEST_F(DBErrorHandlingFSTest, FLushWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.listeners.emplace_back(listener);
  Status s;
@@ -180,13 +181,77 @@ TEST_F(DBErrorHandlingFSTest, FLushWriteError) {
  Destroy(options);
 }

-TEST_F(DBErrorHandlingFSTest, ManifestWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+TEST_F(DBErrorHandlingFSTest, FLushWritRetryableeError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
+  options.create_if_missing = true;
+  options.listeners.emplace_back(listener);
+  Status s;
+
+  listener->EnableAutoRecovery(false);
+  DestroyAndReopen(options);
+
+  IOStatus error_msg = IOStatus::IOError("Retryable IO Error");
+  error_msg.SetRetryable(true);
+
+  Put(Key(1), "val1");
+  SyncPoint::GetInstance()->SetCallBack(
+      "BuildTable:BeforeFinishBuildTable",
+      [&](void*) { fault_fs->SetFilesystemActive(false, error_msg); });
+  SyncPoint::GetInstance()->EnableProcessing();
+  s = Flush();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  SyncPoint::GetInstance()->DisableProcessing();
+  fault_fs->SetFilesystemActive(true);
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+  Reopen(options);
+  ASSERT_EQ("val1", Get(Key(1)));
+
+  Put(Key(2), "val2");
+  SyncPoint::GetInstance()->SetCallBack(
+      "BuildTable:BeforeSyncTable",
+      [&](void*) { fault_fs->SetFilesystemActive(false, error_msg); });
+  SyncPoint::GetInstance()->EnableProcessing();
+  s = Flush();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  SyncPoint::GetInstance()->DisableProcessing();
+  fault_fs->SetFilesystemActive(true);
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+  Reopen(options);
+  ASSERT_EQ("val2", Get(Key(2)));
+
+  Put(Key(3), "val3");
+  SyncPoint::GetInstance()->SetCallBack(
+      "BuildTable:BeforeCloseTableFile",
+      [&](void*) { fault_fs->SetFilesystemActive(false, error_msg); });
+  SyncPoint::GetInstance()->EnableProcessing();
+  s = Flush();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  SyncPoint::GetInstance()->DisableProcessing();
+  fault_fs->SetFilesystemActive(true);
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+  Reopen(options);
+  ASSERT_EQ("val3", Get(Key(3)));
+
+  Destroy(options);
+}
+
+TEST_F(DBErrorHandlingFSTest, ManifestWriteError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  std::shared_ptr<ErrorHandlerFSListener> listener(
+      new ErrorHandlerFSListener());
+  Options options = GetDefaultOptions();
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.listeners.emplace_back(listener);
  Status s;
@@ -222,13 +287,59 @@ TEST_F(DBErrorHandlingFSTest, ManifestWriteError) {
  Close();
 }

-TEST_F(DBErrorHandlingFSTest, DoubleManifestWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+TEST_F(DBErrorHandlingFSTest, ManifestWriteRetryableError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
+  options.create_if_missing = true;
+  options.listeners.emplace_back(listener);
+  Status s;
+  std::string old_manifest;
+  std::string new_manifest;
+
+  listener->EnableAutoRecovery(false);
+  DestroyAndReopen(options);
+  old_manifest = GetManifestNameFromLiveFiles();
+
+  IOStatus error_msg = IOStatus::IOError("Retryable IO Error");
+  error_msg.SetRetryable(true);
+
+  Put(Key(0), "val");
+  Flush();
+  Put(Key(1), "val");
+  SyncPoint::GetInstance()->SetCallBack(
+      "VersionSet::LogAndApply:WriteManifest",
+      [&](void*) { fault_fs->SetFilesystemActive(false, error_msg); });
+  SyncPoint::GetInstance()->EnableProcessing();
+  s = Flush();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->DisableProcessing();
+  fault_fs->SetFilesystemActive(true);
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+
+  new_manifest = GetManifestNameFromLiveFiles();
+  ASSERT_NE(new_manifest, old_manifest);
+
+  Reopen(options);
+  ASSERT_EQ("val", Get(Key(0)));
+  ASSERT_EQ("val", Get(Key(1)));
+  Close();
+}
+
+TEST_F(DBErrorHandlingFSTest, DoubleManifestWriteError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  std::shared_ptr<ErrorHandlerFSListener> listener(
+      new ErrorHandlerFSListener());
+  Options options = GetDefaultOptions();
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.listeners.emplace_back(listener);
  Status s;
@@ -272,12 +383,13 @@ TEST_F(DBErrorHandlingFSTest, DoubleManifestWriteError) {
 }

 TEST_F(DBErrorHandlingFSTest, CompactionManifestWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.level0_file_num_compaction_trigger = 2;
  options.listeners.emplace_back(listener);
@@ -343,13 +455,88 @@ TEST_F(DBErrorHandlingFSTest, CompactionManifestWriteError) {
  Close();
 }

-TEST_F(DBErrorHandlingFSTest, CompactionWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+TEST_F(DBErrorHandlingFSTest, CompactionManifestWriteRetryableError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
+  options.create_if_missing = true;
+  options.level0_file_num_compaction_trigger = 2;
+  options.listeners.emplace_back(listener);
+  Status s;
+  std::string old_manifest;
+  std::string new_manifest;
+  std::atomic<bool> fail_manifest(false);
+  DestroyAndReopen(options);
+  old_manifest = GetManifestNameFromLiveFiles();
+
+  IOStatus error_msg = IOStatus::IOError("Retryable IO Error");
+  error_msg.SetRetryable(true);
+
+  Put(Key(0), "val");
+  Put(Key(2), "val");
+  s = Flush();
+  ASSERT_EQ(s, Status::OK());
+
+  listener->OverrideBGError(Status(error_msg, Status::Severity::kHardError));
+  listener->EnableAutoRecovery(false);
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+      // Wait for flush of 2nd L0 file before starting compaction
+      {{"DBImpl::FlushMemTable:FlushMemTableFinished",
+        "BackgroundCallCompaction:0"},
+       // Wait for compaction to detect manifest write error
+       {"BackgroundCallCompaction:1", "CompactionManifestWriteError:0"},
+       // Make compaction thread wait for error to be cleared
+       {"CompactionManifestWriteError:1",
+        "DBImpl::BackgroundCallCompaction:FoundObsoleteFiles"}});
+  // trigger manifest write failure in compaction thread
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "BackgroundCallCompaction:0", [&](void*) { fail_manifest.store(true); });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "VersionSet::LogAndApply:WriteManifest", [&](void*) {
+        if (fail_manifest.load()) {
+          fault_fs->SetFilesystemActive(false, error_msg);
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  Put(Key(1), "val");
+  s = Flush();
+  ASSERT_EQ(s, Status::OK());
+
+  TEST_SYNC_POINT("CompactionManifestWriteError:0");
+  TEST_SYNC_POINT("CompactionManifestWriteError:1");
+
+  s = dbfull()->TEST_WaitForCompact();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+
+  fault_fs->SetFilesystemActive(true);
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->DisableProcessing();
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+
+  new_manifest = GetManifestNameFromLiveFiles();
+  ASSERT_NE(new_manifest, old_manifest);
+
+  Reopen(options);
+  ASSERT_EQ("val", Get(Key(0)));
+  ASSERT_EQ("val", Get(Key(1)));
+  ASSERT_EQ("val", Get(Key(2)));
+  Close();
+}
+
+TEST_F(DBErrorHandlingFSTest, CompactionWriteError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  std::shared_ptr<ErrorHandlerFSListener> listener(
+      new ErrorHandlerFSListener());
+  Options options = GetDefaultOptions();
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.level0_file_num_compaction_trigger = 2;
  options.listeners.emplace_back(listener);
@@ -386,11 +573,59 @@ TEST_F(DBErrorHandlingFSTest, CompactionWriteError) {
  Destroy(options);
 }

-TEST_F(DBErrorHandlingFSTest, CorruptionError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+TEST_F(DBErrorHandlingFSTest, CompactionWriteRetryableError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  std::shared_ptr<ErrorHandlerFSListener> listener(
+      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
+  options.create_if_missing = true;
+  options.level0_file_num_compaction_trigger = 2;
+  options.listeners.emplace_back(listener);
+  Status s;
+  DestroyAndReopen(options);
+
+  IOStatus error_msg = IOStatus::IOError("Retryable IO Error");
+  error_msg.SetRetryable(true);
+
+  Put(Key(0), "va;");
+  Put(Key(2), "va;");
+  s = Flush();
+  ASSERT_EQ(s, Status::OK());
+
+  listener->OverrideBGError(Status(error_msg, Status::Severity::kHardError));
+  listener->EnableAutoRecovery(false);
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::FlushMemTable:FlushMemTableFinished",
+        "BackgroundCallCompaction:0"}});
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "BackgroundCallCompaction:0",
+      [&](void*) { fault_fs->SetFilesystemActive(false, error_msg); });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  Put(Key(1), "val");
+  s = Flush();
+  ASSERT_EQ(s, Status::OK());
+
+  s = dbfull()->TEST_WaitForCompact();
+  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+
+  fault_fs->SetFilesystemActive(true);
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->DisableProcessing();
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+  Destroy(options);
+}
+
+TEST_F(DBErrorHandlingFSTest, CorruptionError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  Options options = GetDefaultOptions();
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.level0_file_num_compaction_trigger = 2;
  Status s;
@@ -426,12 +661,13 @@ TEST_F(DBErrorHandlingFSTest, CorruptionError) {
 }

 TEST_F(DBErrorHandlingFSTest, AutoRecoverFlushError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.listeners.emplace_back(listener);
  Status s;
@@ -460,12 +696,13 @@ TEST_F(DBErrorHandlingFSTest, AutoRecoverFlushError) {
 }

 TEST_F(DBErrorHandlingFSTest, FailRecoverFlushError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.listeners.emplace_back(listener);
  Status s;
@@ -487,12 +724,13 @@ TEST_F(DBErrorHandlingFSTest, FailRecoverFlushError) {
 }

 TEST_F(DBErrorHandlingFSTest, WALWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.writable_file_max_buffer_size = 32768;
  options.listeners.emplace_back(listener);
@@ -557,13 +795,109 @@ TEST_F(DBErrorHandlingFSTest, WALWriteError) {
  Close();
 }

-TEST_F(DBErrorHandlingFSTest, MultiCFWALWriteError) {
-  FaultInjectionTestFS* fault_fs =
-      new FaultInjectionTestFS(FileSystem::Default().get());
+TEST_F(DBErrorHandlingFSTest, WALWriteRetryableError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
  std::shared_ptr<ErrorHandlerFSListener> listener(
      new ErrorHandlerFSListener());
  Options options = GetDefaultOptions();
-  options.file_system.reset(fault_fs);
+  options.env = fault_fs_env.get();
+  options.create_if_missing = true;
+  options.writable_file_max_buffer_size = 32768;
+  options.listeners.emplace_back(listener);
+  options.paranoid_checks = true;
+  Status s;
+  Random rnd(301);
+
+  DestroyAndReopen(options);
+
+  IOStatus error_msg = IOStatus::IOError("Retryable IO Error");
+  error_msg.SetRetryable(true);
+
+  // For the first batch, write is successful, require sync
+  {
+    WriteBatch batch;
+
+    for (auto i = 0; i < 100; ++i) {
+      batch.Put(Key(i), RandomString(&rnd, 1024));
+    }
+
+    WriteOptions wopts;
+    wopts.sync = true;
+    ASSERT_EQ(dbfull()->Write(wopts, &batch), Status::OK());
+  };
+
+  // For the second batch, the first 2 file Append are successful, then the
+  // following Append fails due to file system retryable IOError.
+  {
+    WriteBatch batch;
+    int write_error = 0;
+
+    for (auto i = 100; i < 200; ++i) {
+      batch.Put(Key(i), RandomString(&rnd, 1024));
+    }
+
+    SyncPoint::GetInstance()->SetCallBack(
+        "WritableFileWriter::Append:BeforePrepareWrite", [&](void*) {
+          write_error++;
+          if (write_error > 2) {
+            fault_fs->SetFilesystemActive(false, error_msg);
+          }
+        });
+    SyncPoint::GetInstance()->EnableProcessing();
+    WriteOptions wopts;
+    wopts.sync = true;
+    s = dbfull()->Write(wopts, &batch);
+    ASSERT_EQ(true, s.IsIOError());
+  }
+  fault_fs->SetFilesystemActive(true);
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->DisableProcessing();
+
+  // Data in corrupted WAL are not stored
+  for (auto i = 0; i < 199; ++i) {
+    if (i < 100) {
+      ASSERT_NE(Get(Key(i)), "NOT_FOUND");
+    } else {
+      ASSERT_EQ(Get(Key(i)), "NOT_FOUND");
+    }
+  }
+
+  // Resume and write a new batch, should be in the WAL
+  s = dbfull()->Resume();
+  ASSERT_EQ(s, Status::OK());
+  {
+    WriteBatch batch;
+
+    for (auto i = 200; i < 300; ++i) {
+      batch.Put(Key(i), RandomString(&rnd, 1024));
+    }
+
+    WriteOptions wopts;
+    wopts.sync = true;
+    ASSERT_EQ(dbfull()->Write(wopts, &batch), Status::OK());
+  };
+
+  Reopen(options);
+  for (auto i = 0; i < 300; ++i) {
+    if (i < 100 || i >= 200) {
+      ASSERT_NE(Get(Key(i)), "NOT_FOUND");
+    } else {
+      ASSERT_EQ(Get(Key(i)), "NOT_FOUND");
+    }
+  }
+  Close();
+}
+
+TEST_F(DBErrorHandlingFSTest, MultiCFWALWriteError) {
+  std::shared_ptr<FaultInjectionTestFS> fault_fs(
+      new FaultInjectionTestFS(FileSystem::Default()));
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  std::shared_ptr<ErrorHandlerFSListener> listener(
+      new ErrorHandlerFSListener());
+  Options options = GetDefaultOptions();
+  options.env = fault_fs_env.get();
  options.create_if_missing = true;
  options.writable_file_max_buffer_size = 32768;
  options.listeners.emplace_back(listener);
@@ -643,6 +977,7 @@ TEST_F(DBErrorHandlingFSTest, MultiCFWALWriteError) {

 TEST_F(DBErrorHandlingFSTest, MultiDBCompactionError) {
  FaultInjectionTestEnv* def_env = new FaultInjectionTestEnv(Env::Default());
+  std::vector<std::unique_ptr<Env>> fault_envs;
  std::vector<FaultInjectionTestFS*> fault_fs;
  std::vector<Options> options;
  std::vector<std::shared_ptr<ErrorHandlerFSListener>> listener;
@@ -654,12 +989,13 @@ TEST_F(DBErrorHandlingFSTest, MultiDBCompactionError) {
  for (auto i = 0; i < kNumDbInstances; ++i) {
    listener.emplace_back(new ErrorHandlerFSListener());
    options.emplace_back(GetDefaultOptions());
-    fault_fs.emplace_back(
-        new FaultInjectionTestFS(FileSystem::Default().get()));
+    fault_fs.emplace_back(new FaultInjectionTestFS(FileSystem::Default()));
+    std::shared_ptr<FileSystem> fs(fault_fs.back());
+    fault_envs.emplace_back(new CompositeEnvWrapper(def_env, fs));
+    options[i].env = fault_envs.back().get();
    options[i].create_if_missing = true;
    options[i].level0_file_num_compaction_trigger = 2;
    options[i].writable_file_max_buffer_size = 32768;
-    options[i].file_system.reset(fault_fs[i]);
    options[i].listeners.emplace_back(listener[i]);
    options[i].sst_file_manager = sfm;
    DB* dbptr;
@@ -742,6 +1078,7 @@ TEST_F(DBErrorHandlingFSTest, MultiDBCompactionError) {

 TEST_F(DBErrorHandlingFSTest, MultiDBVariousErrors) {
  FaultInjectionTestEnv* def_env = new FaultInjectionTestEnv(Env::Default());
+  std::vector<std::unique_ptr<Env>> fault_envs;
  std::vector<FaultInjectionTestFS*> fault_fs;
  std::vector<Options> options;
  std::vector<std::shared_ptr<ErrorHandlerFSListener>> listener;
@@ -753,12 +1090,13 @@ TEST_F(DBErrorHandlingFSTest, MultiDBVariousErrors) {
  for (auto i = 0; i < kNumDbInstances; ++i) {
    listener.emplace_back(new ErrorHandlerFSListener());
    options.emplace_back(GetDefaultOptions());
-    fault_fs.emplace_back(
-        new FaultInjectionTestFS(FileSystem::Default().get()));
+    fault_fs.emplace_back(new FaultInjectionTestFS(FileSystem::Default()));
+    std::shared_ptr<FileSystem> fs(fault_fs.back());
+    fault_envs.emplace_back(new CompositeEnvWrapper(def_env, fs));
+    options[i].env = fault_envs.back().get();
    options[i].create_if_missing = true;
    options[i].level0_file_num_compaction_trigger = 2;
    options[i].writable_file_max_buffer_size = 32768;
-    options[i].file_system.reset(fault_fs[i]);
    options[i].listeners.emplace_back(listener[i]);
    options[i].sst_file_manager = sfm;
    DB* dbptr;
@@ -6,6 +6,7 @@
 #include <functional>

 #include "db/db_test_util.h"
+#include "db/version_edit.h"
 #include "port/port.h"
 #include "port/stack_trace.h"
 #include "rocksdb/sst_file_writer.h"
@@ -41,6 +42,29 @@ class ExternalSSTFileBasicTest
    return db_->IngestExternalFile(files, opts);
  }

+  Status AddFileWithFileChecksum(
+      const std::vector<std::string>& files,
+      const std::vector<std::string>& files_checksums,
+      const std::vector<std::string>& files_checksum_func_names,
+      bool verify_file_checksum = true, bool move_files = false,
+      bool skip_snapshot_check = false, bool write_global_seqno = true) {
+    IngestExternalFileOptions opts;
+    opts.move_files = move_files;
+    opts.snapshot_consistency = !skip_snapshot_check;
+    opts.allow_global_seqno = false;
+    opts.allow_blocking_flush = false;
+    opts.write_global_seqno = write_global_seqno;
+    opts.verify_file_checksum = verify_file_checksum;
+
+    IngestExternalFileArg arg;
+    arg.column_family = db_->DefaultColumnFamily();
+    arg.external_files = files;
+    arg.options = opts;
+    arg.files_checksums = files_checksums;
+    arg.files_checksum_func_names = files_checksum_func_names;
+    return db_->IngestExternalFiles({arg});
+  }
+
  Status GenerateAndAddExternalFile(
      const Options options, std::vector<int> keys,
      const std::vector<ValueType>& value_types,
@@ -174,6 +198,8 @@ TEST_F(ExternalSSTFileBasicTest, Basic) {
  ASSERT_EQ(file1_info.num_range_del_entries, 0);
  ASSERT_EQ(file1_info.smallest_range_del_key, "");
  ASSERT_EQ(file1_info.largest_range_del_key, "");
+  ASSERT_EQ(file1_info.file_checksum, kUnknownFileChecksum);
+  ASSERT_EQ(file1_info.file_checksum_func_name, kUnknownFileChecksumFuncName);
  // sst_file_writer already finished, cannot add this value
  s = sst_file_writer.Put(Key(100), "bad_val");
  ASSERT_FALSE(s.ok()) << s.ToString();
@@ -192,6 +218,369 @@ TEST_F(ExternalSSTFileBasicTest, Basic) {
  DestroyAndRecreateExternalSSTFilesDir();
 }

+class ChecksumVerifyHelper {
+ private:
+  Options options_;
+
+ public:
+  ChecksumVerifyHelper(Options& options) : options_(options) {}
+  ~ChecksumVerifyHelper() {}
+
+  Status GetSingleFileChecksumAndFuncName(
+      const std::string& file_path, std::string* file_checksum,
+      std::string* file_checksum_func_name) {
+    Status s;
+    EnvOptions soptions;
+    std::unique_ptr<SequentialFile> file_reader;
+    s = options_.env->NewSequentialFile(file_path, &file_reader, soptions);
+    if (!s.ok()) {
+      return s;
+    }
+    std::unique_ptr<char[]> scratch(new char[2048]);
+    Slice result;
+    FileChecksumGenFactory* file_checksum_gen_factory =
+        options_.file_checksum_gen_factory.get();
+    if (file_checksum_gen_factory == nullptr) {
+      *file_checksum = kUnknownFileChecksum;
+      *file_checksum_func_name = kUnknownFileChecksumFuncName;
+      return Status::OK();
+    } else {
+      FileChecksumGenContext gen_context;
+      std::unique_ptr<FileChecksumGenerator> file_checksum_gen =
+          file_checksum_gen_factory->CreateFileChecksumGenerator(gen_context);
+      *file_checksum_func_name = file_checksum_gen->Name();
+      s = file_reader->Read(2048, &result, scratch.get());
+      if (!s.ok()) {
+        return s;
+      }
+      while (result.size() != 0) {
+        file_checksum_gen->Update(scratch.get(), result.size());
+        s = file_reader->Read(2048, &result, scratch.get());
+        if (!s.ok()) {
+          return s;
+        }
+      }
+      file_checksum_gen->Finalize();
+      *file_checksum = file_checksum_gen->GetChecksum();
+    }
+    return Status::OK();
+  }
+};
+
+TEST_F(ExternalSSTFileBasicTest, BasicWithFileChecksumCrc32c) {
+  Options options = CurrentOptions();
+  options.file_checksum_gen_factory = GetFileChecksumGenCrc32cFactory();
+  ChecksumVerifyHelper checksum_helper(options);
+
+  SstFileWriter sst_file_writer(EnvOptions(), options);
+
+  // Current file size should be 0 after sst_file_writer init and before open a
+  // file.
+  ASSERT_EQ(sst_file_writer.FileSize(), 0);
+
+  // file1.sst (0 => 99)
+  std::string file1 = sst_files_dir_ + "file1.sst";
+  ASSERT_OK(sst_file_writer.Open(file1));
+  for (int k = 0; k < 100; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val"));
+  }
+  ExternalSstFileInfo file1_info;
+  Status s = sst_file_writer.Finish(&file1_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::string file_checksum, file_checksum_func_name;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file1, &file_checksum, &file_checksum_func_name));
+
+  // Current file size should be non-zero after success write.
+  ASSERT_GT(sst_file_writer.FileSize(), 0);
+
+  ASSERT_EQ(file1_info.file_path, file1);
+  ASSERT_EQ(file1_info.num_entries, 100);
+  ASSERT_EQ(file1_info.smallest_key, Key(0));
+  ASSERT_EQ(file1_info.largest_key, Key(99));
+  ASSERT_EQ(file1_info.num_range_del_entries, 0);
+  ASSERT_EQ(file1_info.smallest_range_del_key, "");
+  ASSERT_EQ(file1_info.largest_range_del_key, "");
+  ASSERT_EQ(file1_info.file_checksum, file_checksum);
+  ASSERT_EQ(file1_info.file_checksum_func_name, file_checksum_func_name);
+  // sst_file_writer already finished, cannot add this value
+  s = sst_file_writer.Put(Key(100), "bad_val");
+  ASSERT_FALSE(s.ok()) << s.ToString();
+  s = sst_file_writer.DeleteRange(Key(100), Key(200));
+  ASSERT_FALSE(s.ok()) << s.ToString();
+
+  DestroyAndReopen(options);
+  // Add file using file path
+  s = DeprecatedAddFile({file1});
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(db_->GetLatestSequenceNumber(), 0U);
+  for (int k = 0; k < 100; k++) {
+    ASSERT_EQ(Get(Key(k)), Key(k) + "_val");
+  }
+
+  DestroyAndRecreateExternalSSTFilesDir();
+}
+
+TEST_F(ExternalSSTFileBasicTest, IngestFileWithFileChecksum) {
+  Options old_options = CurrentOptions();
+  Options options = CurrentOptions();
+  options.file_checksum_gen_factory = GetFileChecksumGenCrc32cFactory();
+  const ImmutableCFOptions ioptions(options);
+  ChecksumVerifyHelper checksum_helper(options);
+
+  SstFileWriter sst_file_writer(EnvOptions(), options);
+
+  // file01.sst (1000 => 1099)
+  std::string file1 = sst_files_dir_ + "file01.sst";
+  ASSERT_OK(sst_file_writer.Open(file1));
+  for (int k = 1000; k < 1100; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val"));
+  }
+  ExternalSstFileInfo file1_info;
+  Status s = sst_file_writer.Finish(&file1_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file1_info.file_path, file1);
+  ASSERT_EQ(file1_info.num_entries, 100);
+  ASSERT_EQ(file1_info.smallest_key, Key(1000));
+  ASSERT_EQ(file1_info.largest_key, Key(1099));
+  std::string file_checksum1, file_checksum_func_name1;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file1, &file_checksum1, &file_checksum_func_name1));
+  ASSERT_EQ(file1_info.file_checksum, file_checksum1);
+  ASSERT_EQ(file1_info.file_checksum_func_name, file_checksum_func_name1);
+
+  // file02.sst (1100 => 1299)
+  std::string file2 = sst_files_dir_ + "file02.sst";
+  ASSERT_OK(sst_file_writer.Open(file2));
+  for (int k = 1100; k < 1300; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val"));
+  }
+  ExternalSstFileInfo file2_info;
+  s = sst_file_writer.Finish(&file2_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file2_info.file_path, file2);
+  ASSERT_EQ(file2_info.num_entries, 200);
+  ASSERT_EQ(file2_info.smallest_key, Key(1100));
+  ASSERT_EQ(file2_info.largest_key, Key(1299));
+  std::string file_checksum2, file_checksum_func_name2;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file2, &file_checksum2, &file_checksum_func_name2));
+  ASSERT_EQ(file2_info.file_checksum, file_checksum2);
+  ASSERT_EQ(file2_info.file_checksum_func_name, file_checksum_func_name2);
+
+  // file03.sst (1300 => 1499)
+  std::string file3 = sst_files_dir_ + "file03.sst";
+  ASSERT_OK(sst_file_writer.Open(file3));
+  for (int k = 1300; k < 1500; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val_overlap"));
+  }
+  ExternalSstFileInfo file3_info;
+  s = sst_file_writer.Finish(&file3_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file3_info.file_path, file3);
+  ASSERT_EQ(file3_info.num_entries, 200);
+  ASSERT_EQ(file3_info.smallest_key, Key(1300));
+  ASSERT_EQ(file3_info.largest_key, Key(1499));
+  std::string file_checksum3, file_checksum_func_name3;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file3, &file_checksum3, &file_checksum_func_name3));
+  ASSERT_EQ(file3_info.file_checksum, file_checksum3);
+  ASSERT_EQ(file3_info.file_checksum_func_name, file_checksum_func_name3);
+
+  // file04.sst (1500 => 1799)
+  std::string file4 = sst_files_dir_ + "file04.sst";
+  ASSERT_OK(sst_file_writer.Open(file4));
+  for (int k = 1500; k < 1800; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val_overlap"));
+  }
+  ExternalSstFileInfo file4_info;
+  s = sst_file_writer.Finish(&file4_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file4_info.file_path, file4);
+  ASSERT_EQ(file4_info.num_entries, 300);
+  ASSERT_EQ(file4_info.smallest_key, Key(1500));
+  ASSERT_EQ(file4_info.largest_key, Key(1799));
+  std::string file_checksum4, file_checksum_func_name4;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file4, &file_checksum4, &file_checksum_func_name4));
+  ASSERT_EQ(file4_info.file_checksum, file_checksum4);
+  ASSERT_EQ(file4_info.file_checksum_func_name, file_checksum_func_name4);
+
+  // file05.sst (1800 => 1899)
+  std::string file5 = sst_files_dir_ + "file05.sst";
+  ASSERT_OK(sst_file_writer.Open(file5));
+  for (int k = 1800; k < 2000; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val_overlap"));
+  }
+  ExternalSstFileInfo file5_info;
+  s = sst_file_writer.Finish(&file5_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file5_info.file_path, file5);
+  ASSERT_EQ(file5_info.num_entries, 200);
+  ASSERT_EQ(file5_info.smallest_key, Key(1800));
+  ASSERT_EQ(file5_info.largest_key, Key(1999));
+  std::string file_checksum5, file_checksum_func_name5;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file5, &file_checksum5, &file_checksum_func_name5));
+  ASSERT_EQ(file5_info.file_checksum, file_checksum5);
+  ASSERT_EQ(file5_info.file_checksum_func_name, file_checksum_func_name5);
+
+  // file06.sst (2000 => 2199)
+  std::string file6 = sst_files_dir_ + "file06.sst";
+  ASSERT_OK(sst_file_writer.Open(file6));
+  for (int k = 2000; k < 2200; k++) {
+    ASSERT_OK(sst_file_writer.Put(Key(k), Key(k) + "_val_overlap"));
+  }
+  ExternalSstFileInfo file6_info;
+  s = sst_file_writer.Finish(&file6_info);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_EQ(file6_info.file_path, file6);
+  ASSERT_EQ(file6_info.num_entries, 200);
+  ASSERT_EQ(file6_info.smallest_key, Key(2000));
+  ASSERT_EQ(file6_info.largest_key, Key(2199));
+  std::string file_checksum6, file_checksum_func_name6;
+  ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+      file6, &file_checksum6, &file_checksum_func_name6));
+  ASSERT_EQ(file6_info.file_checksum, file_checksum6);
+  ASSERT_EQ(file6_info.file_checksum_func_name, file_checksum_func_name6);
+
+  s = AddFileWithFileChecksum({file1}, {file_checksum1, "xyz"},
+                              {file_checksum1}, true, false, false, false);
+  // does not care the checksum input since db does not enable file checksum
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_OK(env_->FileExists(file1));
+  std::vector<LiveFileMetaData> live_files;
+  dbfull()->GetLiveFilesMetaData(&live_files);
+  std::set<std::string> set1;
+  for (auto f : live_files) {
+    set1.insert(f.name);
+    ASSERT_EQ(f.file_checksum, kUnknownFileChecksum);
+    ASSERT_EQ(f.file_checksum_func_name, kUnknownFileChecksumFuncName);
+  }
+
+  // Reopen Db with checksum enabled
+  Reopen(options);
+  // Enable verify_file_checksum option
+  // The checksum vector does not match, fail the ingestion
+  s = AddFileWithFileChecksum({file2}, {file_checksum2, "xyz"},
+                              {file_checksum_func_name2}, true, false, false,
+                              false);
+  ASSERT_FALSE(s.ok()) << s.ToString();
+
+  // Enable verify_file_checksum option
+  // The checksum name does not match, fail the ingestion
+  s = AddFileWithFileChecksum({file2}, {file_checksum2}, {"xyz"}, true, false,
+                              false, false);
+  ASSERT_FALSE(s.ok()) << s.ToString();
+
+  // Enable verify_file_checksum option
+  // The checksum itself does not match, fail the ingestion
+  s = AddFileWithFileChecksum({file2}, {"xyz"}, {file_checksum_func_name2},
+                              true, false, false, false);
+  ASSERT_FALSE(s.ok()) << s.ToString();
+
+  // Enable verify_file_checksum option
+  // All matches, ingestion is successful
+  s = AddFileWithFileChecksum({file2}, {file_checksum2},
+                              {file_checksum_func_name2}, true, false, false,
+                              false);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::vector<LiveFileMetaData> live_files1;
+  dbfull()->GetLiveFilesMetaData(&live_files1);
+  for (auto f : live_files1) {
+    if (set1.find(f.name) == set1.end()) {
+      ASSERT_EQ(f.file_checksum, file_checksum2);
+      ASSERT_EQ(f.file_checksum_func_name, file_checksum_func_name2);
+      set1.insert(f.name);
+    }
+  }
+  ASSERT_OK(env_->FileExists(file2));
+
+  // Enable verify_file_checksum option
+  // No checksum information is provided, generate it when ingesting
+  std::vector<std::string> checksum, checksum_func;
+  s = AddFileWithFileChecksum({file3}, checksum, checksum_func, true, false,
+                              false, false);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::vector<LiveFileMetaData> live_files2;
+  dbfull()->GetLiveFilesMetaData(&live_files2);
+  for (auto f : live_files2) {
+    if (set1.find(f.name) == set1.end()) {
+      ASSERT_EQ(f.file_checksum, file_checksum3);
+      ASSERT_EQ(f.file_checksum_func_name, file_checksum_func_name3);
+      set1.insert(f.name);
+    }
+  }
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_OK(env_->FileExists(file3));
+
+  // Does not enable verify_file_checksum options
+  // The checksum name does not match, fail the ingestion
+  s = AddFileWithFileChecksum({file4}, {file_checksum4}, {"xyz"}, false, false,
+                              false, false);
+  ASSERT_FALSE(s.ok()) << s.ToString();
+
+  // Does not enable verify_file_checksum options
+  // Checksum function name matches, store the checksum being ingested.
+  s = AddFileWithFileChecksum({file4}, {"asd"}, {file_checksum_func_name4},
+                              false, false, false, false);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::vector<LiveFileMetaData> live_files3;
+  dbfull()->GetLiveFilesMetaData(&live_files3);
+  for (auto f : live_files3) {
+    if (set1.find(f.name) == set1.end()) {
+      ASSERT_FALSE(f.file_checksum == file_checksum4);
+      ASSERT_EQ(f.file_checksum, "asd");
+      ASSERT_EQ(f.file_checksum_func_name, file_checksum_func_name4);
+      set1.insert(f.name);
+    }
+  }
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_OK(env_->FileExists(file4));
+
+  // enable verify_file_checksum options, DB enable checksum, and enable
+  // write_global_seq. So the checksum stored is different from the one
+  // ingested due to the sequence number changes.
+  s = AddFileWithFileChecksum({file5}, {file_checksum5},
+                              {file_checksum_func_name5}, true, false, false,
+                              true);
+  ASSERT_OK(s);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::vector<LiveFileMetaData> live_files4;
+  dbfull()->GetLiveFilesMetaData(&live_files4);
+  for (auto f : live_files4) {
+    if (set1.find(f.name) == set1.end()) {
+      std::string cur_checksum5, cur_checksum_func_name5;
+      ASSERT_OK(checksum_helper.GetSingleFileChecksumAndFuncName(
+          dbname_ + f.name, &cur_checksum5, &cur_checksum_func_name5));
+      ASSERT_EQ(f.file_checksum, cur_checksum5);
+      ASSERT_EQ(f.file_checksum_func_name, file_checksum_func_name5);
+      set1.insert(f.name);
+    }
+  }
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_OK(env_->FileExists(file5));
+
+  // Does not enable verify_file_checksum options and also the ingested file
+  // checksum information is empty. DB will generate and store the checksum
+  // in Manifest.
+  std::vector<std::string> files_c6, files_name6;
+  s = AddFileWithFileChecksum({file6}, files_c6, files_name6, false, false,
+                              false, false);
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  std::vector<LiveFileMetaData> live_files6;
+  dbfull()->GetLiveFilesMetaData(&live_files6);
+  for (auto f : live_files6) {
+    if (set1.find(f.name) == set1.end()) {
+      ASSERT_EQ(f.file_checksum, file_checksum6);
+      ASSERT_EQ(f.file_checksum_func_name, file_checksum_func_name6);
+      set1.insert(f.name);
+    }
+  }
+  ASSERT_TRUE(s.ok()) << s.ToString();
+  ASSERT_OK(env_->FileExists(file6));
+}
+
 TEST_F(ExternalSSTFileBasicTest, NoCopy) {
  Options options = CurrentOptions();
  const ImmutableCFOptions ioptions(options);
@@ -28,6 +28,8 @@ namespace ROCKSDB_NAMESPACE {

 Status ExternalSstFileIngestionJob::Prepare(
    const std::vector<std::string>& external_files_paths,
+    const std::vector<std::string>& files_checksums,
+    const std::vector<std::string>& files_checksum_func_names,
    uint64_t next_file_number, SuperVersion* sv) {
  Status status;

@@ -68,7 +70,7 @@ Status ExternalSstFileIngestionJob::Prepare(
                                   info2->smallest_internal_key) < 0;
        });

-    for (size_t i = 0; i < num_files - 1; i++) {
+    for (size_t i = 0; i + 1 < num_files; i++) {
      if (sstableKeyCompare(ucmp, sorted_files[i]->largest_internal_key,
                            sorted_files[i + 1]->smallest_internal_key) >= 0) {
        files_overlap_ = true;
@@ -142,6 +144,9 @@ Status ExternalSstFileIngestionJob::Prepare(
      break;
    }
    f.internal_file_path = path_inside_db;
+    // Initialize the checksum information of ingested files.
+    f.file_checksum = kUnknownFileChecksum;
+    f.file_checksum_func_name = kUnknownFileChecksumFuncName;
    ingestion_path_ids.insert(f.fd.GetPathId());
  }

@@ -160,6 +165,128 @@ Status ExternalSstFileIngestionJob::Prepare(
  }
  TEST_SYNC_POINT("ExternalSstFileIngestionJob::AfterSyncDir");

+  // Generate and check the sst file checksum. Note that, if
+  // IngestExternalFileOptions::write_global_seqno is true, we will not update
+  // the checksum information in the files_to_ingests_ here, since the file is
+  // upadted with the new global_seqno. After global_seqno is updated, DB will
+  // generate the new checksum and store it in the Manifest. In all other cases
+  // if ingestion_options_.write_global_seqno == true and
+  // verify_file_checksum is false, we only check the checksum function name.
+  if (status.ok() && db_options_.file_checksum_gen_factory != nullptr) {
+    if (ingestion_options_.verify_file_checksum == false &&
+        files_checksums.size() == files_to_ingest_.size() &&
+        files_checksum_func_names.size() == files_to_ingest_.size()) {
+      // Only when verify_file_checksum == false and the checksum for ingested
+      // files are provided, DB will use the provided checksum and does not
+      // generate the checksum for ingested files.
+      need_generate_file_checksum_ = false;
+    } else {
+      need_generate_file_checksum_ = true;
+    }
+    FileChecksumGenContext gen_context;
+    std::unique_ptr<FileChecksumGenerator> file_checksum_gen =
+        db_options_.file_checksum_gen_factory->CreateFileChecksumGenerator(
+            gen_context);
+    std::vector<std::string> generated_checksums;
+    std::vector<std::string> generated_checksum_func_names;
+    // Step 1: generate the checksum for ingested sst file.
+    if (need_generate_file_checksum_) {
+      for (size_t i = 0; i < files_to_ingest_.size(); i++) {
+        std::string generated_checksum, generated_checksum_func_name;
+        IOStatus io_s = GenerateOneFileChecksum(
+            fs_, files_to_ingest_[i].internal_file_path,
+            db_options_.file_checksum_gen_factory.get(), &generated_checksum,
+            &generated_checksum_func_name,
+            ingestion_options_.verify_checksums_readahead_size,
+            db_options_.allow_mmap_reads);
+        if (!io_s.ok()) {
+          status = io_s;
+          ROCKS_LOG_WARN(db_options_.info_log,
+                         "Sst file checksum generation of file: %s failed: %s",
+                         files_to_ingest_[i].internal_file_path.c_str(),
+                         status.ToString().c_str());
+          break;
+        }
+        if (ingestion_options_.write_global_seqno == false) {
+          files_to_ingest_[i].file_checksum = generated_checksum;
+          files_to_ingest_[i].file_checksum_func_name =
+              generated_checksum_func_name;
+        }
+        generated_checksums.push_back(generated_checksum);
+        generated_checksum_func_names.push_back(generated_checksum_func_name);
+      }
+    }
+
+    // Step 2: based on the verify_file_checksum and ingested checksum
+    // information, do the verification.
+    if (status.ok()) {
+      if (files_checksums.size() == files_to_ingest_.size() &&
+          files_checksum_func_names.size() == files_to_ingest_.size()) {
+        // Verify the checksum and checksum function name.
+        if (ingestion_options_.verify_file_checksum) {
+          for (size_t i = 0; i < files_to_ingest_.size(); i++) {
+            if (files_checksum_func_names[i] !=
+                generated_checksum_func_names[i]) {
+              status = Status::InvalidArgument(
+                  "Checksum function name does not match with the checksum "
+                  "function name of this DB");
+              ROCKS_LOG_WARN(
+                  db_options_.info_log,
+                  "Sst file checksum verification of file: %s failed: %s",
+                  external_files_paths[i].c_str(), status.ToString().c_str());
+              break;
+            }
+            if (files_checksums[i] != generated_checksums[i]) {
+              status = Status::Corruption(
+                  "Ingested checksum does not match with the generated "
+                  "checksum");
+              ROCKS_LOG_WARN(
+                  db_options_.info_log,
+                  "Sst file checksum verification of file: %s failed: %s",
+                  files_to_ingest_[i].internal_file_path.c_str(),
+                  status.ToString().c_str());
+              break;
+            }
+          }
+        } else {
+          // If verify_file_checksum is not enabled, we only verify the
+          // checksum function name. If it does not match, fail the ingestion.
+          // If matches, we trust the ingested checksum information and store
+          // in the Manifest.
+          for (size_t i = 0; i < files_to_ingest_.size(); i++) {
+            if (files_checksum_func_names[i] != file_checksum_gen->Name()) {
+              status = Status::InvalidArgument(
+                  "Checksum function name does not match with the checksum "
+                  "function name of this DB");
+              ROCKS_LOG_WARN(
+                  db_options_.info_log,
+                  "Sst file checksum verification of file: %s failed: %s",
+                  external_files_paths[i].c_str(), status.ToString().c_str());
+              break;
+            }
+            files_to_ingest_[i].file_checksum = files_checksums[i];
+            files_to_ingest_[i].file_checksum_func_name =
+                files_checksum_func_names[i];
+          }
+        }
+      } else if (files_checksums.size() != files_checksum_func_names.size() ||
+                 (files_checksums.size() == files_checksum_func_names.size() &&
+                  files_checksums.size() != 0)) {
+        // The checksum or checksum function name vector are not both empty
+        // and they are incomplete.
+        status = Status::InvalidArgument(
+            "The checksum information of ingested sst files are nonempty and "
+            "the size of checksums or the size of the checksum function "
+            "names "
+            "does not match with the number of ingested sst files");
+        ROCKS_LOG_WARN(
+            db_options_.info_log,
+            "The ingested sst files checksum information is incomplete: %s",
+            status.ToString().c_str());
+      }
+    }
+  }
+
  // TODO: The following is duplicated with Cleanup().
  if (!status.ok()) {
    // We failed, remove all files that we copied into the db
@@ -245,6 +372,11 @@ Status ExternalSstFileIngestionJob::Run() {
      return status;
    }

+    status = GenerateChecksumForIngestedFile(&f);
+    if (!status.ok()) {
+      return status;
+    }
+
    // We use the import time as the ancester time. This is the time the data
    // is written to the database.
    int64_t temp_current_time = 0;
@@ -255,11 +387,11 @@ Status ExternalSstFileIngestionJob::Run() {
          static_cast<uint64_t>(temp_current_time);
    }

-    edit_.AddFile(
-        f.picked_level, f.fd.GetNumber(), f.fd.GetPathId(), f.fd.GetFileSize(),
-        f.smallest_internal_key, f.largest_internal_key, f.assigned_seqno,
-        f.assigned_seqno, false, kInvalidBlobFileNumber, oldest_ancester_time,
-        current_time, kUnknownFileChecksum, kUnknownFileChecksumFuncName);
+    edit_.AddFile(f.picked_level, f.fd.GetNumber(), f.fd.GetPathId(),
+                  f.fd.GetFileSize(), f.smallest_internal_key,
+                  f.largest_internal_key, f.assigned_seqno, f.assigned_seqno,
+                  false, kInvalidBlobFileNumber, oldest_ancester_time,
+                  current_time, f.file_checksum, f.file_checksum_func_name);
  }
  return status;
 }
@@ -687,6 +819,31 @@ Status ExternalSstFileIngestionJob::AssignGlobalSeqnoForIngestedFile(
  return Status::OK();
 }

+IOStatus ExternalSstFileIngestionJob::GenerateChecksumForIngestedFile(
+    IngestedFileInfo* file_to_ingest) {
+  if (db_options_.file_checksum_gen_factory == nullptr ||
+      need_generate_file_checksum_ == false ||
+      ingestion_options_.write_global_seqno == false) {
+    // If file_checksum_gen_factory is not set, we are not able to generate
+    // the checksum. if write_global_seqno is false, it means we will use
+    // file checksum generated during Prepare(). This step will be skipped.
+    return IOStatus::OK();
+  }
+  std::string file_checksum, file_checksum_func_name;
+  IOStatus io_s = GenerateOneFileChecksum(
+      fs_, file_to_ingest->internal_file_path,
+      db_options_.file_checksum_gen_factory.get(), &file_checksum,
+      &file_checksum_func_name,
+      ingestion_options_.verify_checksums_readahead_size,
+      db_options_.allow_mmap_reads);
+  if (!io_s.ok()) {
+    return io_s;
+  }
+  file_to_ingest->file_checksum = file_checksum;
+  file_to_ingest->file_checksum_func_name = file_checksum_func_name;
+  return IOStatus::OK();
+}
+
 bool ExternalSstFileIngestionJob::IngestedFileFitInLevel(
    const IngestedFileInfo* file_to_ingest, int level) {
  if (level == 0) {
@@ -63,6 +63,10 @@ struct IngestedFileInfo {
  // ingestion_options.move_files is false by default, thus copy_file is true
  // by default.
  bool copy_file = true;
+  // The checksum of ingested file
+  std::string file_checksum;
+  // The name of checksum function that generate the checksum
+  std::string file_checksum_func_name;
 };

 class ExternalSstFileIngestionJob {
@@ -90,6 +94,8 @@ class ExternalSstFileIngestionJob {

  // Prepare the job by copying external files into the DB.
  Status Prepare(const std::vector<std::string>& external_files_paths,
+                 const std::vector<std::string>& files_checksums,
+                 const std::vector<std::string>& files_checksum_func_names,
                 uint64_t next_file_number, SuperVersion* sv);

  // Check if we need to flush the memtable before running the ingestion job
@@ -148,6 +154,8 @@ class ExternalSstFileIngestionJob {
  // Set the file global sequence number to `seqno`
  Status AssignGlobalSeqnoForIngestedFile(IngestedFileInfo* file_to_ingest,
                                          SequenceNumber seqno);
+  // Generate the file checksum and store in the IngestedFileInfo
+  IOStatus GenerateChecksumForIngestedFile(IngestedFileInfo* file_to_ingest);

  // Check if `file_to_ingest` can fit in level `level`
  // REQUIRES: Mutex held
@@ -175,6 +183,9 @@ class ExternalSstFileIngestionJob {
  // Set in ExternalSstFileIngestionJob::Prepare(), if true all files are
  // ingested in L0
  bool files_overlap_{false};
+  // Set in ExternalSstFileIngestionJob::Prepare(), if true and DB
+  // file_checksum_gen_factory is set, DB will generate checksum each file.
+  bool need_generate_file_checksum_{true};
 };

 }  // namespace ROCKSDB_NAMESPACE
--- a/Show More
+++ b/Show More