Fix an issue with unnecessary capture in lambda expressions

Closes https://github.com/facebook/rocksdb/issues/3900
refactor constructor of LRUCacheShard
2026-07-07 22:55:23 +08:00 · 2018-05-25 16:27:17 +02:00 · 2018-05-23 18:57:42 -07:00 · 2018-05-23 18:42:08 -07:00 · 2018-05-23 16:12:59 -07:00 · 2018-05-22 13:57:17 -07:00
364 changed files with 15593 additions and 8159 deletions
@@ -16,7 +16,7 @@
 #    See thirdparty.inc for more information.
 #        sample command: cmake -G "Visual Studio 15 Win64" -DWITH_GFLAGS=1 -DWITH_SNAPPY=1 -DWITH_JEMALLOC=1 -DWITH_JNI=1 ..
 # 4. Then build the project in debug mode (you may want to add /m[:<N>] flag to run msbuild in <N> parallel threads
-#                                          or simply /m ot use all avail cores)
+#                                          or simply /m to use all avail cores)
 #        msbuild rocksdb.sln
 #
 #        rocksdb.sln build features exclusions of test only code in Release. If you build ALL_BUILD then everything
@@ -64,9 +64,10 @@ else()
      find_package(JeMalloc REQUIRED)
      add_definitions(-DROCKSDB_JEMALLOC -DJEMALLOC_NO_DEMANGLE)
      include_directories(${JEMALLOC_INCLUDE_DIR})
+      list(APPEND THIRDPARTY_LIBS ${JEMALLOC_LIBRARIES})
    endif()
  endif()
-  
+
  # No config file for this
  option(WITH_GFLAGS "build with GFlags" ON)
  if(WITH_GFLAGS)
@@ -132,19 +133,17 @@ endif()

 string(REGEX REPLACE "[^0-9a-f]+" "" GIT_SHA "${GIT_SHA}")

-set(SH_CMD "sh")
-execute_process(COMMAND
-  ${SH_CMD} -c "build_tools/version.sh full"
-  WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-  OUTPUT_VARIABLE ROCKSDB_VERSION
-)
-string(STRIP "${ROCKSDB_VERSION}" ROCKSDB_VERSION)
-execute_process(COMMAND
-  ${SH_CMD} -c "build_tools/version.sh major"
-  WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-  OUTPUT_VARIABLE ROCKSDB_VERSION_MAJOR
-)
-string(STRIP "${ROCKSDB_VERSION_MAJOR}" ROCKSDB_VERSION_MAJOR)
+
+# Read rocksdb version from version.h header file.
+file(READ include/rocksdb/version.h version_header_file)
+string(REGEX MATCH "#define ROCKSDB_MAJOR ([0-9]+)" _ ${version_header_file})
+set(ROCKSDB_VERSION_MAJOR ${CMAKE_MATCH_1})
+string(REGEX MATCH "#define ROCKSDB_MINOR ([0-9]+)" _ ${version_header_file})
+set(ROCKSDB_VERSION_MINOR ${CMAKE_MATCH_1})
+string(REGEX MATCH "#define ROCKSDB_PATCH ([0-9]+)" _ ${version_header_file})
+set(ROCKSDB_VERSION_PATCH ${CMAKE_MATCH_1})
+set(ROCKSDB_VERSION ${ROCKSDB_VERSION_MAJOR}.${ROCKSDB_VERSION_MINOR}.${ROCKSDB_VERSION_PATCH})
+

 option(WITH_MD_LIBRARY "build with MD" ON)
 if(WIN32 AND MSVC)
@@ -229,6 +228,7 @@ int main() {
 unset(CMAKE_REQUIRED_FLAGS)
 if(HAVE_SSE42)
  add_definitions(-DHAVE_SSE42)
+  add_definitions(-DHAVE_PCLMUL)
 elseif(FORCE_SSE42)
  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
 endif()
@@ -285,20 +285,28 @@ if(WITH_UBSAN)
  endif()
 endif()

-find_package(NUMA)
-if(NUMA_FOUND)
+option(WITH_NUMA "build with NUMA policy support" OFF)
+if(WITH_NUMA)
+  find_package(NUMA REQUIRED)
  add_definitions(-DNUMA)
  include_directories(${NUMA_INCLUDE_DIR})
  list(APPEND THIRDPARTY_LIBS ${NUMA_LIBRARIES})
 endif()

-find_package(TBB)
-if(TBB_FOUND)
+option(WITH_TBB "build with Threading Building Blocks (TBB)" OFF)
+if(WITH_TBB)
+  find_package(TBB REQUIRED)
  add_definitions(-DTBB)
  include_directories(${TBB_INCLUDE_DIR})
  list(APPEND THIRDPARTY_LIBS ${TBB_LIBRARIES})
 endif()

+# Stall notifications eat some performance from inserts
+option(DISABLE_STALL_NOTIF "Build with stall notifications" OFF)
+if(DISABLE_STALL_NOTIF)
+  add_definitions(-DROCKSDB_DISABLE_STALL_NOTIFICATION)
+endif()
+
 # Used to run CI build and tests so we can run faster
 set(OPTIMIZE_DEBUG_DEFAULT 0)        # Debug build is unoptimized by default use -DOPTDBG=1 to optimize

@@ -308,6 +316,22 @@ else()
   set(OPTIMIZE_DEBUG ${OPTIMIZE_DEBUG_DEFAULT})
 endif()

+if(DEFINED USE_RTTI)
+  if(USE_RTTI)
+    message(STATUS "Enabling RTTI")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DROCKSDB_USE_RTTI")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DROCKSDB_USE_RTTI")
+  else()
+    message(STATUS "Disabling RTTI")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fno-rtti")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fno-rtti")
+  endif()
+else()
+  message(STATUS "Enabling RTTI in Debug builds only (default)")
+  set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DROCKSDB_USE_RTTI")
+  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fno-rtti")
+endif()
+
 if(MSVC)
  if((${OPTIMIZE_DEBUG} EQUAL 1))
    message(STATUS "Debug optimization is enabled")
@@ -455,6 +479,7 @@ set(SOURCES
        db/flush_scheduler.cc
        db/forward_iterator.cc
        db/internal_stats.cc
+        db/logs_with_prep_tracker.cc
        db/log_reader.cc
        db/log_writer.cc
        db/malloc_stats.cc
@@ -569,6 +594,7 @@ set(SOURCES
        util/status_message.cc
        util/string_util.cc
        util/sync_point.cc
+        util/sync_point_impl.cc
        util/testutil.cc
        util/thread_local.cc
        util/threadpool_imp.cc
@@ -657,8 +683,12 @@ if(WIN32)
    port/win/env_default.cc
    port/win/port_win.cc
    port/win/win_logger.cc
-    port/win/win_thread.cc
+    port/win/win_thread.cc)
+
+if(WITH_XPRESS)
+  list(APPEND SOURCES
    port/win/xpress_win.cc)
+endif()

 if(WITH_JEMALLOC)
  list(APPEND SOURCES
@@ -675,6 +705,14 @@ endif()
 set(ROCKSDB_STATIC_LIB rocksdb${ARTIFACT_SUFFIX})
 set(ROCKSDB_SHARED_LIB rocksdb-shared${ARTIFACT_SUFFIX})
 set(ROCKSDB_IMPORT_LIB ${ROCKSDB_SHARED_LIB})
+
+option(WITH_LIBRADOS "Build with librados" OFF)
+if(WITH_LIBRADOS)
+  list(APPEND SOURCES
+    utilities/env_librados.cc)
+  list(APPEND THIRDPARTY_LIBS rados)
+endif()
+
 if(WIN32)
  set(SYSTEM_LIBS ${SYSTEM_LIBS} Shlwapi.lib Rpcrt4.lib)
  set(LIBS ${ROCKSDB_STATIC_LIB} ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})
@@ -693,13 +731,6 @@ else()
                        OUTPUT_NAME "rocksdb")
 endif()

-option(WITH_LIBRADOS "Build with librados" OFF)
-if(WITH_LIBRADOS)
-  list(APPEND SOURCES
-    utilities/env_librados.cc)
-  list(APPEND THIRDPARTY_LIBS rados)
-endif()
-
 add_library(${ROCKSDB_STATIC_LIB} STATIC ${SOURCES})
 target_link_libraries(${ROCKSDB_STATIC_LIB}
  ${THIRDPARTY_LIBS} ${SYSTEM_LIBS})
@@ -814,6 +845,7 @@ if(WITH_TESTS)
        db/db_inplace_update_test.cc
        db/db_io_failure_test.cc
        db/db_iter_test.cc
+        db/db_iter_stress_test.cc
        db/db_iterator_test.cc
        db/db_log_iter_test.cc
        db/db_memtable_test.cc
@@ -832,6 +864,7 @@ if(WITH_TESTS)
        db/db_write_test.cc
        db/dbformat_test.cc
        db/deletefile_test.cc
+        db/obsolete_files_test.cc
        db/external_sst_file_basic_test.cc
        db/external_sst_file_test.cc
        db/fault_injection_test.cc
@@ -1,24 +1,40 @@
 # Rocksdb Change Log
-## 5.13.4 (6/12/2018)
-### Bug Fixes
-* Fix regression bug of Prev() with ReadOptions.iterate_upper_bound.
-
-## 5.13.3 (6/6/2018)
-### Bug Fixes
-* Fix assertion when reading bloom filter of SST files containing range deletions but no data
-
-## 5.13.2 (5/25/2018)
+## Unreleased
 ### Public API Change
+* For users of `Statistics` objects created via `CreateDBStatistics()`, the format of the string returned by its `ToString()` method has changed.
+
+## 5.14.0 (5/16/2018)
+### Public API Change
+* Add a BlockBasedTableOption to align uncompressed data blocks on the smaller of block size or page size boundary, to reduce flash reads by avoiding reads spanning 4K pages.
+* The background thread naming convention changed (on supporting platforms) to "rocksdb:<thread pool priority><thread number>", e.g., "rocksdb:low0".
+* Add a new ticker stat rocksdb.number.multiget.keys.found to count number of keys successfully read in MultiGet calls
+* Touch-up to write-related counters in PerfContext. New counters added: write_scheduling_flushes_compactions_time, write_thread_wait_nanos. Counters whose behavior was fixed or modified: write_memtable_time, write_pre_and_post_process_time, write_delay_time.
+* Posix Env's NewRandomRWFile() will fail if the file doesn't exist.
+* Now, `DBOptions::use_direct_io_for_flush_and_compaction` only applies to background writes, and `DBOptions::use_direct_reads` applies to both user reads and background reads. This conforms with Linux's `open(2)` manpage, which advises against simultaneously reading a file in buffered and direct modes, due to possibly undefined behavior and degraded performance.
+* Iterator::Valid() always returns false if !status().ok(). So, now when doing a Seek() followed by some Next()s, there's no need to check status() after every operation.
+* Iterator::Seek()/SeekForPrev()/SeekToFirst()/SeekToLast() always resets status().
 * Introduced `CompressionOptions::kDefaultCompressionLevel`, which is a generic way to tell RocksDB to use the compression library's default level. It is now the default value for `CompressionOptions::level`. Previously the level defaulted to -1, which gave poor compression ratios in ZSTD.

-### Bug Fixes
-* Fix segfault caused by object premature destruction (PR #3898)
-* Fix an issue with unnecessary capture in lambda expressions (PR #3904)
-
-## 5.13.1 (4/30/2018)
 ### New Features
+* Introduce TTL for level compaction so that all files older than ttl go through the compaction process to get rid of old data.
+* TransactionDBOptions::write_policy can be configured to enable WritePrepared 2PC transactions. Read more about them in the wiki.
+* Add DB properties "rocksdb.block-cache-capacity", "rocksdb.block-cache-usage", "rocksdb.block-cache-pinned-usage" to show block cache usage.
 * Add `Env::LowerThreadPoolCPUPriority(Priority)` method, which lowers the CPU priority of background (esp. compaction) threads to minimize interference with foreground tasks.
-* Eliminate use of temporary directories in BackupEngine to improve reliability on distributed file systems.
+* Fsync parent directory after deleting a file in delete scheduler.
+* In level-based compaction, if bottom-pri thread pool was setup via `Env::SetBackgroundThreads()`, compactions to the bottom level will be delegated to that thread pool.
+* `prefix_extractor` has been moved from ImmutableCFOptions to MutableCFOptions, meaning it can be dynamically changed without a DB restart.
+
+### Bug Fixes
+* Fsync after writing global seq number to the ingestion file in ExternalSstFileIngestionJob.
+* Fix WAL corruption caused by race condition between user write thread and FlushWAL when two_write_queue is not set.
+* Fix `BackupableDBOptions::max_valid_backups_to_open` to not delete backup files when refcount cannot be accurately determined.
+* Fix memory leak when pin_l0_filter_and_index_blocks_in_cache is used with partitioned filters
+* Disable rollback of merge operands in WritePrepared transactions to work around an issue in MyRocks. It can be enabled back by setting TransactionDBOptions::rollback_merge_operands to true.
+* Fix wrong results by ReverseBytewiseComparator::FindShortSuccessor()
+
+### Java API Changes
+* Add `BlockBasedTableConfig.setBlockCache` to allow sharing a block cache across DB instances.
+* Added SstFileManager to the Java API to allow managing SST files across DB instances.

 ## 5.13.0 (3/20/2018)
 ### Public API Change
@@ -30,15 +46,11 @@
 * Avoid unnecessarily flushing in `CompactRange()` when the range specified by the user does not overlap unflushed memtables.
 * If `ColumnFamilyOptions::max_subcompactions` is set greater than one, we now parallelize large manual level-based compactions.
 * Add "rocksdb.live-sst-files-size" DB property to return total bytes of all SST files belong to the latest LSM tree.
+* NewSstFileManager to add an argument bytes_max_delete_chunk with default 64MB. With this argument, a file larger than 64MB will be ftruncated multiple times based on this size.

 ### Bug Fixes
 * Fix a leak in prepared_section_completed_ where the zeroed entries would not removed from the map.
 * Fix WAL corruption caused by race condition between user write thread and backup/checkpoint thread.
-* Fsync after writing global seq number to the ingestion file in ExternalSstFileIngestionJob.
-* Fix memory leak when pin_l0_filter_and_index_blocks_in_cache is used with partitioned filters
-
-### Java API Changes
-* Add `BlockBasedTableConfig.setBlockCache` to allow sharing a block cache across DB instances.

 ## 5.12.0 (2/14/2018)
 ### Public API Change
@@ -76,7 +76,9 @@ ifeq ($(MAKECMDGOALS),install)
 endif

 ifeq ($(MAKECMDGOALS),rocksdbjavastatic)
-	DEBUG_LEVEL=0
+	ifneq ($(DEBUG_LEVEL),2)
+		DEBUG_LEVEL=0
+	endif
 endif

 ifeq ($(MAKECMDGOALS),rocksdbjavastaticrelease)
@@ -222,6 +224,9 @@ ifdef COMPILE_WITH_TSAN
 	PROFILING_FLAGS =
 	# LUA is not supported under TSAN
 	LUA_PATH =
+	# Limit keys for crash test under TSAN to avoid error:
+	# "ThreadSanitizer: DenseSlabAllocator overflow. Dying."
+	CRASH_TEST_EXT_ARGS += --max_key=1000000
 endif

 # AIX doesn't work with -pg
@@ -276,7 +281,7 @@ endif
 default: all

 WARNING_FLAGS = -W -Wextra -Wall -Wsign-compare -Wshadow \
-  -Wno-unused-parameter
+  -Wunused-parameter

 ifeq ($(PLATFORM), OS_OPENBSD)
 	WARNING_FLAGS += -Wno-unused-lambda-capture
@@ -397,6 +402,7 @@ TESTS = \
 	db_blob_index_test \
 	db_bloom_filter_test \
 	db_iter_test \
+	db_iter_stress_test \
 	db_log_iter_test \
 	db_compaction_filter_test \
 	db_compaction_test \
@@ -474,6 +480,7 @@ TESTS = \
 	write_batch_with_index_test \
 	write_controller_test\
 	deletefile_test \
+	obsolete_files_test \
 	table_test \
 	geodb_test \
 	delete_scheduler_test \
@@ -642,7 +649,7 @@ ifeq ($(HAVE_POWER8),1)
 shared_all_libobjects = $(shared_libobjects) $(shared-ppc-objects)
 endif
 $(SHARED4): $(shared_all_libobjects)
-	$(CXX) $(PLATFORM_SHARED_LDFLAGS)$(SHARED3) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(shared_libobjects) $(LDFLAGS) -o $@
+	$(CXX) $(PLATFORM_SHARED_LDFLAGS)$(SHARED3) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(shared_all_libobjects) $(LDFLAGS) -o $@

 endif  # PLATFORM_SHARED_EXT

@@ -795,7 +802,7 @@ check_0:
 	  | grep -E '$(tests-regexp)'					\
 	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu '{} >& t/log-{/}'

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

 .PHONY: valgrind_check_0
 valgrind_check_0:
@@ -1189,6 +1196,9 @@ db_tailing_iter_test: db/db_tailing_iter_test.o db/db_test_util.o $(LIBOBJECTS)
 db_iter_test: db/db_iter_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+db_iter_stress_test: db/db_iter_stress_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 db_universal_compaction_test: db/db_universal_compaction_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1380,6 +1390,9 @@ options_file_test: db/options_file_test.o $(LIBOBJECTS) $(TESTHARNESS)
 deletefile_test: db/deletefile_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

+obsolete_files_test: db/obsolete_files_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(AM_LINK)
+
 geodb_test: utilities/geodb/geodb_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(AM_LINK)

@@ -1715,7 +1728,9 @@ rocksdbjavastatic: $(java_static_all_libobjects)
 	  -o ./java/target/$(ROCKSDBJNILIB) $(JNI_NATIVE_SOURCES) \
 	  $(java_static_all_libobjects) $(COVERAGEFLAGS) \
 	  $(JAVA_COMPRESSIONS) $(JAVA_STATIC_LDFLAGS)
-	cd java/target;strip $(STRIPFLAGS) $(ROCKSDBJNILIB)
+	cd java/target;if [ "$(DEBUG_LEVEL)" == "0" ]; then \
+		strip $(STRIPFLAGS) $(ROCKSDBJNILIB); \
+	fi
 	cd java;jar -cf target/$(ROCKSDB_JAR) HISTORY*.md
 	cd java/target;jar -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
 	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
@@ -25,6 +25,10 @@ rocksdb_compiler_flags = [
    "-DTBB",
    # Needed to compile in fbcode
    "-Wno-expansion-to-defined",
+    # Added missing flags from output of build_detect_platform
+    "-DROCKSDB_PTHREAD_ADAPTIVE_MUTEX",
+    "-DROCKSDB_BACKTRACE",
+    "-Wshorten-64-to-32",
 ]

 rocksdb_external_deps = [
@@ -99,6 +103,7 @@ cpp_library(
        "db/internal_stats.cc",
        "db/log_reader.cc",
        "db/log_writer.cc",
+        "db/logs_with_prep_tracker.cc",
        "db/malloc_stats.cc",
        "db/managed_iterator.cc",
        "db/memtable.cc",
@@ -215,6 +220,7 @@ cpp_library(
        "util/status_message.cc",
        "util/string_util.cc",
        "util/sync_point.cc",
+        "util/sync_point_impl.cc",
        "util/thread_local.cc",
        "util/threadpool_imp.cc",
        "util/transaction_test_util.cc",
@@ -554,6 +560,11 @@ ROCKS_TESTS = [
        "db/db_iter_test.cc",
        "serial",
    ],
+    [
+        "db_iter_stress_test",
+        "db/db_iter_stress_test.cc",
+        "serial",
+    ],
    [
        "db_iterator_test",
        "db/db_iterator_test.cc",
@@ -824,6 +835,11 @@ ROCKS_TESTS = [
        "utilities/object_registry_test.cc",
        "serial",
    ],
+    [
+        "obsolete_files_test",
+        "db/obsolete_files_test.cc",
+        "serial",
+    ],
    [
        "optimistic_transaction_test",
        "utilities/transactions/optimistic_transaction_test.cc",
@@ -29,6 +29,10 @@ rocksdb_compiler_flags = [
    "-DTBB",
    # Needed to compile in fbcode
    "-Wno-expansion-to-defined",
+    # Added missing flags from output of build_detect_platform
+    "-DROCKSDB_PTHREAD_ADAPTIVE_MUTEX",
+    "-DROCKSDB_BACKTRACE",
+    "-Wshorten-64-to-32",
 ]

 rocksdb_external_deps = [
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 #
 # Detects OS we're compiling on and outputs a file specified by the first
 # argument, which in turn gets read while processing Makefile.
@@ -53,13 +53,11 @@ if [ -z "$ROCKSDB_NO_FBCODE" -a -d /mnt/gvfs/third-party ]; then
    FBCODE_BUILD="true"
    # If we're compiling with TSAN we need pic build
    PIC_BUILD=$COMPILE_WITH_TSAN
-    if [ -n "$ROCKSDB_FBCODE_BUILD_WITH_481" ]; then
-      # we need this to build with MySQL. Don't use for other purposes.
-      source "$PWD/build_tools/fbcode_config4.8.1.sh"
-    elif [ -n "$ROCKSDB_FBCODE_BUILD_WITH_5xx" ]; then
+    if [ -z "$ROCKSDB_FBCODE_BUILD_WITH_481" ]; then
      source "$PWD/build_tools/fbcode_config.sh"
    else
-      source "$PWD/build_tools/fbcode_config_platform007.sh"
+      # we need this to build with MySQL. Don't use for other purposes.
+      source "$PWD/build_tools/fbcode_config4.8.1.sh"
    fi
 fi

@@ -68,11 +66,23 @@ rm -f "$OUTPUT"
 touch "$OUTPUT"

 if test -z "$CC"; then
-   CC=cc
+    if [ -x "$(command -v cc)" ]; then
+        CC=cc
+    elif [ -x "$(command -v clang)" ]; then
+        CC=clang
+    else
+        CC=cc
+    fi
 fi

 if test -z "$CXX"; then
-    CXX=g++
+    if [ -x "$(command -v g++)" ]; then
+        CXX=g++
+    elif [ -x "$(command -v clang++)" ]; then
+        CXX=clang++
+    else
+        CXX=g++
+    fi
 fi

 # Detect OS
@@ -89,7 +99,7 @@ if test -z "$CLANG_SCAN_BUILD"; then
 fi

 if test -z "$CLANG_ANALYZER"; then
-    CLANG_ANALYZER=$(which clang++ 2> /dev/null)
+    CLANG_ANALYZER=$(command -v clang++ 2> /dev/null)
 fi

 if test -z "$FIND"; then
@@ -134,6 +144,8 @@ case "$TARGET_OS" in
        COMMON_FLAGS="$COMMON_FLAGS -DOS_LINUX"
        if [ -z "$USE_CLANG" ]; then
            COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp"
+        else
+            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -latomic"
        fi
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lrt"
        # PORT_FILES=port/linux/linux_specific.cc
@@ -186,6 +198,8 @@ case "$TARGET_OS" in
        COMMON_FLAGS="$COMMON_FLAGS -DCYGWIN"
        if [ -z "$USE_CLANG" ]; then
            COMMON_FLAGS="$COMMON_FLAGS -fno-builtin-memcmp"
+        else
+            PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -latomic"
        fi
        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lpthread -lrt"
        # PORT_FILES=port/linux/linux_specific.cc
@@ -500,9 +514,9 @@ if test -z "$PORTABLE"; then
  elif test -n "`echo $TARGET_ARCHITECTURE | grep ^arm`"; then
    # TODO: Handle this with approprite options.
    COMMON_FLAGS="$COMMON_FLAGS"
-  elif [ "$TARGET_OS" == IOS ]; then
+  elif [ "$TARGET_OS" == "IOS" ]; then
    COMMON_FLAGS="$COMMON_FLAGS"
-  elif [ "$TARGET_OS" != AIX ] && [ "$TARGET_OS" != SunOS ]; then
+  elif [ "$TARGET_OS" != "AIX" ] && [ "$TARGET_OS" != "SunOS" ]; then
    COMMON_FLAGS="$COMMON_FLAGS -march=native "
  elif test "$USE_SSE"; then
    COMMON_FLAGS="$COMMON_FLAGS -msse4.2 -mpclmul"
@@ -1,18 +0,0 @@
-GCC_BASE=/mnt/gvfs/third-party2/gcc/6e8e715624fd15256a7970073387793dfcf79b46/7.x/centos7-native/b2ef2b6
-CLANG_BASE=/mnt/gvfs/third-party2/llvm-fb/ef37e1faa1c29782abfac1ae65a291b9b7966f6d/stable/centos7-native/c9f9104
-LIBGCC_BASE=/mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc
-GLIBC_BASE=/mnt/gvfs/third-party2/glibc/60d6f124a78798b73944f5ba87c2306ae3460153/2.26/platform007/f259413
-SNAPPY_BASE=/mnt/gvfs/third-party2/snappy/7f9bdaada18f59bc27ec2b0871eb8a6144343aef/1.1.3/platform007/ca4da3d
-ZLIB_BASE=/mnt/gvfs/third-party2/zlib/22c2d65676fb7c23cfa797c4f6937f38b026f3cf/1.2.8/platform007/ca4da3d
-BZIP2_BASE=/mnt/gvfs/third-party2/bzip2/dc49a21c5fceec6456a7a28a94dcd16690af1337/1.0.6/platform007/ca4da3d
-LZ4_BASE=/mnt/gvfs/third-party2/lz4/907b498203d297947f3bb70b9466f47e100f1873/r131/platform007/ca4da3d
-ZSTD_BASE=/mnt/gvfs/third-party2/zstd/3ee276cbacfad3074e3f07bf826ac47f06970f4e/1.3.5/platform007/15a3614
-GFLAGS_BASE=/mnt/gvfs/third-party2/gflags/0b9929d2588991c65a57168bf88aff2db87c5d48/2.2.0/platform007/ca4da3d
-JEMALLOC_BASE=/mnt/gvfs/third-party2/jemalloc/9c910d36d6235cc40e8ff559358f1833452300ca/master/platform007/5b0f53e
-NUMA_BASE=/mnt/gvfs/third-party2/numa/9cbf2460284c669ed19c3ccb200a71f7dd7e53c7/2.0.11/platform007/ca4da3d
-LIBUNWIND_BASE=/mnt/gvfs/third-party2/libunwind/bf3d7497fe4e6d007354f0adffa16ce3003f8338/1.3/platform007/6f3e0a9
-TBB_BASE=/mnt/gvfs/third-party2/tbb/ff4e0b093534704d8abab678a4fd7f5ea7b094c7/2018_U5/platform007/ca4da3d
-KERNEL_HEADERS_BASE=/mnt/gvfs/third-party2/kernel-headers/b5c4a61a5c483ba24722005ae07895971a2ac707/fb/platform007/da39a3e
-BINUTILS_BASE=/mnt/gvfs/third-party2/binutils/92ff90349e2f43ea0a8246d8b1cf17b6869013e3/2.29.1/centos7-native/da39a3e
-VALGRIND_BASE=/mnt/gvfs/third-party2/valgrind/f3f697a28122e6bcd513273dd9c1ff23852fc59f/3.13.0/platform007/ca4da3d
-LUA_BASE=/mnt/gvfs/third-party2/lua/f0cd714433206d5139df61659eb7b28b1dea6683/5.3.4/platform007/5007832
@@ -1,157 +0,0 @@
-#!/bin/sh
-#
-# Set environment variables so that we can compile rocksdb using
-# fbcode settings.  It uses the latest g++ and clang compilers and also
-# uses jemalloc
-# Environment variables that change the behavior of this script:
-# PIC_BUILD -- if true, it will only take pic versions of libraries from fbcode. libraries that don't have pic variant will not be included
-
-
-BASEDIR=`dirname $BASH_SOURCE`
-source "$BASEDIR/dependencies_platform007.sh"
-
-CFLAGS=""
-
-# libgcc
-LIBGCC_INCLUDE="$LIBGCC_BASE/include/c++/7.3.0"
-LIBGCC_LIBS=" -L $LIBGCC_BASE/lib"
-
-# glibc
-GLIBC_INCLUDE="$GLIBC_BASE/include"
-GLIBC_LIBS=" -L $GLIBC_BASE/lib"
-
-# snappy
-SNAPPY_INCLUDE=" -I $SNAPPY_BASE/include/"
-if test -z $PIC_BUILD; then
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy.a"
-else
-  SNAPPY_LIBS=" $SNAPPY_BASE/lib/libsnappy_pic.a"
-fi
-CFLAGS+=" -DSNAPPY"
-
-if test -z $PIC_BUILD; then
-  # location of zlib headers and libraries
-  ZLIB_INCLUDE=" -I $ZLIB_BASE/include/"
-  ZLIB_LIBS=" $ZLIB_BASE/lib/libz.a"
-  CFLAGS+=" -DZLIB"
-
-  # location of bzip headers and libraries
-  BZIP_INCLUDE=" -I $BZIP2_BASE/include/"
-  BZIP_LIBS=" $BZIP2_BASE/lib/libbz2.a"
-  CFLAGS+=" -DBZIP2"
-
-  LZ4_INCLUDE=" -I $LZ4_BASE/include/"
-  LZ4_LIBS=" $LZ4_BASE/lib/liblz4.a"
-  CFLAGS+=" -DLZ4"
-fi
-
-ZSTD_INCLUDE=" -I $ZSTD_BASE/include/"
-if test -z $PIC_BUILD; then
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd.a"
-else
-  ZSTD_LIBS=" $ZSTD_BASE/lib/libzstd_pic.a"
-fi
-CFLAGS+=" -DZSTD"
-
-# location of gflags headers and libraries
-GFLAGS_INCLUDE=" -I $GFLAGS_BASE/include/"
-if test -z $PIC_BUILD; then
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags.a"
-else
-  GFLAGS_LIBS=" $GFLAGS_BASE/lib/libgflags_pic.a"
-fi
-CFLAGS+=" -DGFLAGS=gflags"
-
-# location of jemalloc
-JEMALLOC_INCLUDE=" -I $JEMALLOC_BASE/include/"
-JEMALLOC_LIB=" $JEMALLOC_BASE/lib/libjemalloc.a"
-
-if test -z $PIC_BUILD; then
-  # location of numa
-  NUMA_INCLUDE=" -I $NUMA_BASE/include/"
-  NUMA_LIB=" $NUMA_BASE/lib/libnuma.a"
-  CFLAGS+=" -DNUMA"
-
-  # location of libunwind
-  LIBUNWIND="$LIBUNWIND_BASE/lib/libunwind.a"
-fi
-
-# location of TBB
-TBB_INCLUDE=" -isystem $TBB_BASE/include/"
-if test -z $PIC_BUILD; then
-  TBB_LIBS="$TBB_BASE/lib/libtbb.a"
-else
-  TBB_LIBS="$TBB_BASE/lib/libtbb_pic.a"
-fi
-CFLAGS+=" -DTBB"
-
-# use Intel SSE support for checksum calculations
-export USE_SSE=1
-export PORTABLE=1
-
-BINUTILS="$BINUTILS_BASE/bin"
-AR="$BINUTILS/ar"
-
-DEPS_INCLUDE="$SNAPPY_INCLUDE $ZLIB_INCLUDE $BZIP_INCLUDE $LZ4_INCLUDE $ZSTD_INCLUDE $GFLAGS_INCLUDE $NUMA_INCLUDE $TBB_INCLUDE"
-
-STDLIBS="-L $GCC_BASE/lib64"
-
-CLANG_BIN="$CLANG_BASE/bin"
-CLANG_LIB="$CLANG_BASE/lib"
-CLANG_SRC="$CLANG_BASE/../../src"
-
-CLANG_ANALYZER="$CLANG_BIN/clang++"
-CLANG_SCAN_BUILD="$CLANG_SRC/llvm/tools/clang/tools/scan-build/bin/scan-build"
-
-if [ -z "$USE_CLANG" ]; then
-  # gcc
-  CC="$GCC_BASE/bin/gcc"
-  CXX="$GCC_BASE/bin/g++"
-
-  CFLAGS+=" -B$BINUTILS/gold"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  JEMALLOC=1
-else
-  # clang
-  CLANG_INCLUDE="$CLANG_LIB/clang/stable/include"
-  CC="$CLANG_BIN/clang"
-  CXX="$CLANG_BIN/clang++"
-
-  KERNEL_HEADERS_INCLUDE="$KERNEL_HEADERS_BASE/include"
-
-  CFLAGS+=" -B$BINUTILS/gold -nostdinc -nostdlib"
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x "
-  CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/7.x/x86_64-facebook-linux "
-  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -isystem $CLANG_INCLUDE"
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
-  CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
-  CFLAGS+=" -Wno-expansion-to-defined "
-  CXXFLAGS="-nostdinc++"
-fi
-
-CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42"
-CXXFLAGS+=" $CFLAGS"
-
-EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS"
-EXEC_LDFLAGS+=" -B$BINUTILS/gold"
-EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/platform007/lib/ld.so"
-EXEC_LDFLAGS+=" $LIBUNWIND"
-EXEC_LDFLAGS+=" -Wl,-rpath=/usr/local/fbcode/platform007/lib"
-# required by libtbb
-EXEC_LDFLAGS+=" -ldl"
-
-PLATFORM_LDFLAGS="$LIBGCC_LIBS $GLIBC_LIBS $STDLIBS -lgcc -lstdc++"
-
-EXEC_LDFLAGS_SHARED="$SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $TBB_LIBS"
-
-VALGRIND_VER="$VALGRIND_BASE/bin/"
-
-# lua not supported because it's on track for deprecation, I think
-LUA_PATH=
-LUA_LIB=
-
-export CC CXX AR CFLAGS CXXFLAGS EXEC_LDFLAGS EXEC_LDFLAGS_SHARED VALGRIND_VER JEMALLOC_LIB JEMALLOC_INCLUDE CLANG_ANALYZER CLANG_SCAN_BUILD LUA_PATH LUA_LIB
@@ -85,9 +85,8 @@ NON_SHM="TMPD=/tmp/rocksdb_test_tmp"
 GCC_481="ROCKSDB_FBCODE_BUILD_WITH_481=1"
 ASAN="COMPILE_WITH_ASAN=1"
 CLANG="USE_CLANG=1"
-# in gcc-5 there are known problems with TSAN like https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71090.
-# using platform007 gives us gcc-8 or higher which has that bug fixed.
-TSAN="ROCKSDB_FBCODE_BUILD_WITH_PLATFORM007=1 COMPILE_WITH_TSAN=1"
+LITE="OPT=\"-DROCKSDB_LITE -g\""
+TSAN="COMPILE_WITH_TSAN=1"
 UBSAN="COMPILE_WITH_UBSAN=1"
 DISABLE_JEMALLOC="DISABLE_JEMALLOC=1"
 HTTP_PROXY="https_proxy=http://fwdproxy.29.prn1:8080 http_proxy=http://fwdproxy.29.prn1:8080 ftp_proxy=http://fwdproxy.29.prn1:8080"
@@ -53,45 +53,6 @@ function get_lib_base()
  log_variable $__res_var
 }

-###########################################################
-#                platform007 dependencies                 #
-###########################################################
-
-OUTPUT="$BASEDIR/dependencies_platform007.sh"
-
-rm -f "$OUTPUT"
-touch "$OUTPUT"
-
-echo "Writing dependencies to $OUTPUT"
-
-# Compilers locations
-GCC_BASE=`readlink -f $TP2_LATEST/gcc/7.x/centos7-native/*/`
-CLANG_BASE=`readlink -f $TP2_LATEST/llvm-fb/stable/centos7-native/*/`
-
-log_variable GCC_BASE
-log_variable CLANG_BASE
-
-# Libraries locations
-get_lib_base libgcc     7.x     platform007
-get_lib_base glibc      2.26    platform007
-get_lib_base snappy     LATEST  platform007
-get_lib_base zlib       LATEST  platform007
-get_lib_base bzip2      LATEST  platform007
-get_lib_base lz4        LATEST  platform007
-get_lib_base zstd       LATEST  platform007
-get_lib_base gflags     LATEST  platform007
-get_lib_base jemalloc   LATEST  platform007
-get_lib_base numa       LATEST  platform007
-get_lib_base libunwind  LATEST  platform007
-get_lib_base tbb        LATEST  platform007
-
-get_lib_base kernel-headers fb platform007
-get_lib_base binutils   LATEST centos7-native
-get_lib_base valgrind   LATEST platform007
-get_lib_base lua        5.3.4  platform007
-
-git diff $OUTPUT
-
 ###########################################################
 #                   5.x dependencies                      #
 ###########################################################
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 if [ "$#" = "0" ]; then
  echo "Usage: $0 major|minor|patch|full"
  exit 1
@@ -52,7 +52,7 @@ namespace rocksdb {

 class CacheBench;
 namespace {
-void deleter(const Slice& key, void* value) {
+void deleter(const Slice& /*key*/, void* value) {
    delete reinterpret_cast<char *>(value);
 }

@@ -13,8 +13,8 @@

 namespace rocksdb {

-std::shared_ptr<Cache> NewClockCache(size_t capacity, int num_shard_bits,
-                                     bool strict_capacity_limit) {
+std::shared_ptr<Cache> NewClockCache(size_t /*capacity*/, int /*num_shard_bits*/,
+                                     bool /*strict_capacity_limit*/) {
  // Clock cache not supported.
  return nullptr;
 }
@@ -367,7 +367,9 @@ ClockCacheShard::~ClockCacheShard() {
  for (auto& handle : list_) {
    uint32_t flags = handle.flags.load(std::memory_order_relaxed);
    if (InCache(flags) || CountRefs(flags) > 0) {
-      (*handle.deleter)(handle.key, handle.value);
+      if (handle.deleter != nullptr) {
+        (*handle.deleter)(handle.key, handle.value);
+      }
      delete[] handle.key.data();
    }
  }
@@ -99,14 +99,20 @@ void LRUHandleTable::Resize() {
  length_ = new_length;
 }

-LRUCacheShard::LRUCacheShard()
-    : capacity_(0), high_pri_pool_usage_(0), strict_capacity_limit_(false),
-      high_pri_pool_ratio_(0), high_pri_pool_capacity_(0), usage_(0),
+LRUCacheShard::LRUCacheShard(size_t capacity, bool strict_capacity_limit,
+                             double high_pri_pool_ratio)
+    : capacity_(0),
+      high_pri_pool_usage_(0),
+      strict_capacity_limit_(strict_capacity_limit),
+      high_pri_pool_ratio_(high_pri_pool_ratio),
+      high_pri_pool_capacity_(0),
+      usage_(0),
      lru_usage_(0) {
  // Make empty circular linked list
  lru_.next = &lru_;
  lru_.prev = &lru_;
  lru_low_pri_ = &lru_;
+  SetCapacity(capacity);
 }

 LRUCacheShard::~LRUCacheShard() {}
@@ -244,17 +250,13 @@ void* LRUCacheShard::operator new(size_t size) {
  return port::cacheline_aligned_alloc(size);
 }

-void* LRUCacheShard::operator new[](size_t size) {
-  return port::cacheline_aligned_alloc(size);
-}
+void* LRUCacheShard::operator new(size_t /*size*/, void* ptr) { return ptr; }

 void LRUCacheShard::operator delete(void *memblock) {
  port::cacheline_aligned_free(memblock);
 }

-void LRUCacheShard::operator delete[](void* memblock) {
-  port::cacheline_aligned_free(memblock);
-}
+void LRUCacheShard::operator delete(void* /*memblock*/, void* /*ptr*/) {}

 void LRUCacheShard::SetCapacity(size_t capacity) {
  autovector<LRUHandle*> last_reference_list;
@@ -473,15 +475,21 @@ LRUCache::LRUCache(size_t capacity, int num_shard_bits,
                   bool strict_capacity_limit, double high_pri_pool_ratio)
    : ShardedCache(capacity, num_shard_bits, strict_capacity_limit) {
  num_shards_ = 1 << num_shard_bits;
-  shards_ = new LRUCacheShard[num_shards_];
-  SetCapacity(capacity);
-  SetStrictCapacityLimit(strict_capacity_limit);
+  shards_ = reinterpret_cast<LRUCacheShard*>(
+      port::cacheline_aligned_alloc(sizeof(LRUCacheShard) * num_shards_));
+  size_t per_shard = (capacity + (num_shards_ - 1)) / num_shards_;
  for (int i = 0; i < num_shards_; i++) {
-    shards_[i].SetHighPriorityPoolRatio(high_pri_pool_ratio);
+    new (&shards_[i])
+        LRUCacheShard(per_shard, strict_capacity_limit, high_pri_pool_ratio);
  }
 }

-LRUCache::~LRUCache() { delete[] shards_; }
+LRUCache::~LRUCache() {
+  for (int i = 0; i < num_shards_; i++) {
+    shards_[i].~LRUCacheShard();
+  }
+  port::cacheline_aligned_free(shards_);
+}

 CacheShard* LRUCache::GetShard(int shard) {
  return reinterpret_cast<CacheShard*>(&shards_[shard]);
@@ -156,7 +156,8 @@ class LRUHandleTable {
 // A single shard of sharded cache.
 class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard : public CacheShard {
 public:
-  LRUCacheShard();
+  LRUCacheShard(size_t capacity, bool strict_capacity_limit,
+                double high_pri_pool_ratio);
  virtual ~LRUCacheShard();

  // Separate from constructor so caller can easily make an array of LRUCache
@@ -206,13 +207,16 @@ class ALIGN_AS(CACHE_LINE_SIZE) LRUCacheShard : public CacheShard {
  double GetHighPriPoolRatio();

  // Overloading to aligned it to cache line size
+  // They are used by tests.
  void* operator new(size_t);

-  void* operator new[](size_t);
+  // placement new
+  void* operator new(size_t, void*);

  void operator delete(void *);

-  void operator delete[](void*);
+  // placement delete, does nothing.
+  void operator delete(void*, void*);

 private:
  void LRU_Remove(LRUHandle* e);
@@ -7,6 +7,7 @@

 #include <string>
 #include <vector>
+#include "port/port.h"
 #include "util/testharness.h"

 namespace rocksdb {
@@ -17,19 +18,8 @@ class LRUCacheTest : public testing::Test {
  ~LRUCacheTest() {}

  void NewCache(size_t capacity, double high_pri_pool_ratio = 0.0) {
-    cache_.reset(
-#if defined(_MSC_VER)
-#pragma warning(push)
-#pragma warning(disable: 4316) // We've validated the alignment with the new operators
-#endif
-      new LRUCacheShard()
-#if defined(_MSC_VER)
-#pragma warning(pop)
-#endif
-    );
-    cache_->SetCapacity(capacity);
-    cache_->SetStrictCapacityLimit(false);
-    cache_->SetHighPriorityPoolRatio(high_pri_pool_ratio);
+    cache_.reset(new LRUCacheShard(capacity, false /*strict_capcity_limit*/,
+                                   high_pri_pool_ratio));
  }

  void Insert(const std::string& key,
@@ -114,7 +104,7 @@ TEST_F(LRUCacheTest, BasicLRU) {
  ValidateLRUList({"e", "z", "d", "u", "v"});
 }

-TEST_F(LRUCacheTest, MidPointInsertion) {
+TEST_F(LRUCacheTest, EntriesWithPriority) {
  // Allocate 2 cache entries to high-pri pool.
  NewCache(5, 0.45);

@@ -5,13 +5,17 @@
 # TBB_LIBRARIES - List of libraries when using TBB.
 # TBB_FOUND - True if TBB found.

+if(NOT DEFINED TBB_ROOT_DIR)
+  set(TBB_ROOT_DIR "$ENV{TBBROOT}")
+endif()
+
 find_path(TBB_INCLUDE_DIR
 NAMES tbb/tbb.h
 HINTS ${TBB_ROOT_DIR}/include)

 find_library(TBB_LIBRARIES
 NAMES tbb
-HINTS ${TBB_ROOT_DIR}/lib)
+HINTS ${TBB_ROOT_DIR}/lib ENV LIBRARY_PATH)

 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(TBB DEFAULT_MSG TBB_LIBRARIES TBB_INCLUDE_DIR)
@@ -39,7 +39,7 @@ namespace rocksdb {
 class TableFactory;

 TableBuilder* NewTableBuilder(
-    const ImmutableCFOptions& ioptions,
+    const ImmutableCFOptions& ioptions, const MutableCFOptions& moptions,
    const InternalKeyComparator& internal_comparator,
    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
        int_tbl_prop_collector_factories,
@@ -52,19 +52,20 @@ TableBuilder* NewTableBuilder(
          TablePropertiesCollectorFactory::Context::kUnknownColumnFamily) ==
         column_family_name.empty());
  return ioptions.table_factory->NewTableBuilder(
-      TableBuilderOptions(
-          ioptions, internal_comparator, int_tbl_prop_collector_factories,
-          compression_type, compression_opts, compression_dict, skip_filters,
-          column_family_name, level, creation_time, oldest_key_time),
+      TableBuilderOptions(ioptions, moptions, internal_comparator,
+                          int_tbl_prop_collector_factories, compression_type,
+                          compression_opts, compression_dict, skip_filters,
+                          column_family_name, level, creation_time,
+                          oldest_key_time),
      column_family_id, file);
 }

 Status BuildTable(
    const std::string& dbname, Env* env, const ImmutableCFOptions& ioptions,
-    const MutableCFOptions& /*mutable_cf_options*/,
-    const EnvOptions& env_options, TableCache* table_cache,
-    InternalIterator* iter, std::unique_ptr<InternalIterator> range_del_iter,
-    FileMetaData* meta, const InternalKeyComparator& internal_comparator,
+    const MutableCFOptions& mutable_cf_options, const EnvOptions& env_options,
+    TableCache* table_cache, InternalIterator* iter,
+    std::unique_ptr<InternalIterator> range_del_iter, FileMetaData* meta,
+    const InternalKeyComparator& internal_comparator,
    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
        int_tbl_prop_collector_factories,
    uint32_t column_family_id, const std::string& column_family_name,
@@ -92,7 +93,7 @@ Status BuildTable(
    return s;
  }

-  std::string fname = TableFileName(ioptions.db_paths, meta->fd.GetNumber(),
+  std::string fname = TableFileName(ioptions.cf_paths, meta->fd.GetNumber(),
                                    meta->fd.GetPathId());
 #ifndef ROCKSDB_LITE
  EventHelpers::NotifyTableFileCreationStarted(
@@ -122,10 +123,11 @@ Status BuildTable(
      file_writer.reset(new WritableFileWriter(std::move(file), env_options,
                                               ioptions.statistics));
      builder = NewTableBuilder(
-          ioptions, internal_comparator, int_tbl_prop_collector_factories,
-          column_family_id, column_family_name, file_writer.get(), compression,
-          compression_opts, level, nullptr /* compression_dict */,
-          false /* skip_filters */, creation_time, oldest_key_time);
+          ioptions, mutable_cf_options, internal_comparator,
+          int_tbl_prop_collector_factories, column_family_id,
+          column_family_name, file_writer.get(), compression, compression_opts,
+          level, nullptr /* compression_dict */, false /* skip_filters */,
+          creation_time, oldest_key_time);
    }

    MergeHelper merge(env, internal_comparator.user_comparator(),
@@ -195,7 +197,8 @@ Status BuildTable(
      // to cache it here for further user reads
      std::unique_ptr<InternalIterator> it(table_cache->NewIterator(
          ReadOptions(), env_options, internal_comparator, meta->fd,
-          nullptr /* range_del_agg */, nullptr,
+          nullptr /* range_del_agg */,
+          mutable_cf_options.prefix_extractor.get(), nullptr,
          (internal_stats == nullptr) ? nullptr
                                      : internal_stats->GetFileReadHist(0),
          false /* for_compaction */, nullptr /* arena */,
@@ -43,7 +43,7 @@ class InternalIterator;
 // @param compression_dict Data for presetting the compression library's
 //    dictionary, or nullptr.
 TableBuilder* NewTableBuilder(
-    const ImmutableCFOptions& options,
+    const ImmutableCFOptions& options, const MutableCFOptions& moptions,
    const InternalKeyComparator& internal_comparator,
    const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
        int_tbl_prop_collector_factories,
@@ -38,6 +38,7 @@
 #include "rocksdb/utilities/transaction_db.h"
 #include "rocksdb/utilities/write_batch_with_index.h"
 #include "rocksdb/write_batch.h"
+#include "rocksdb/perf_context.h"
 #include "utilities/merge_operators.h"

 using rocksdb::BytewiseComparator;
@@ -101,6 +102,10 @@ using rocksdb::OptimisticTransactionDB;
 using rocksdb::OptimisticTransactionOptions;
 using rocksdb::Transaction;
 using rocksdb::Checkpoint;
+using rocksdb::TransactionLogIterator;
+using rocksdb::BatchResult;
+using rocksdb::PerfLevel;
+using rocksdb::PerfContext;

 using std::shared_ptr;

@@ -132,6 +137,8 @@ struct rocksdb_cuckoo_table_options_t  { CuckooTableOptions rep; };
 struct rocksdb_seqfile_t         { SequentialFile*   rep; };
 struct rocksdb_randomfile_t      { RandomAccessFile* rep; };
 struct rocksdb_writablefile_t    { WritableFile*     rep; };
+struct rocksdb_wal_iterator_t { TransactionLogIterator* rep; };
+struct rocksdb_wal_readoptions_t { TransactionLogIterator::ReadOptions rep; };
 struct rocksdb_filelock_t        { FileLock*         rep; };
 struct rocksdb_logger_t          { shared_ptr<Logger>  rep; };
 struct rocksdb_cache_t           { shared_ptr<Cache>   rep; };
@@ -140,7 +147,8 @@ struct rocksdb_column_family_handle_t  { ColumnFamilyHandle* rep; };
 struct rocksdb_envoptions_t      { EnvOptions        rep; };
 struct rocksdb_ingestexternalfileoptions_t  { IngestExternalFileOptions rep; };
 struct rocksdb_sstfilewriter_t   { SstFileWriter*    rep; };
-struct rocksdb_ratelimiter_t     { RateLimiter*      rep; };
+struct rocksdb_ratelimiter_t     { shared_ptr<RateLimiter>      rep; };
+struct rocksdb_perfcontext_t     { PerfContext*      rep; };
 struct rocksdb_pinnableslice_t {
  PinnableSlice rep;
 };
@@ -926,6 +934,54 @@ rocksdb_iterator_t* rocksdb_create_iterator(
  return result;
 }

+rocksdb_wal_iterator_t* rocksdb_get_updates_since(
+        rocksdb_t* db, uint64_t seq_number,
+        const rocksdb_wal_readoptions_t* options,
+        char** errptr) {
+  std::unique_ptr<TransactionLogIterator> iter;
+  TransactionLogIterator::ReadOptions ro;
+  if (options!=nullptr) {
+      ro = options->rep;
+  }
+  if (SaveError(errptr, db->rep->GetUpdatesSince(seq_number, &iter, ro))) {
+    return nullptr;
+  }
+  rocksdb_wal_iterator_t* result = new rocksdb_wal_iterator_t;
+  result->rep = iter.release();
+  return result;
+}
+
+void rocksdb_wal_iter_next(rocksdb_wal_iterator_t* iter) {
+    iter->rep->Next();
+}
+
+unsigned char rocksdb_wal_iter_valid(const rocksdb_wal_iterator_t* iter) {
+    return iter->rep->Valid();
+}
+
+void rocksdb_wal_iter_status (const rocksdb_wal_iterator_t* iter, char** errptr) {
+    SaveError(errptr, iter->rep->status());
+}
+
+void rocksdb_wal_iter_destroy (const rocksdb_wal_iterator_t* iter) {
+  delete iter->rep;
+  delete iter;
+}
+
+rocksdb_writebatch_t* rocksdb_wal_iter_get_batch (const rocksdb_wal_iterator_t* iter, uint64_t* seq) {
+  rocksdb_writebatch_t* result = rocksdb_writebatch_create();
+  BatchResult wal_batch = iter->rep->GetBatch();
+  result->rep = * wal_batch.writeBatchPtr.release();
+  if (seq != nullptr) {
+    *seq = wal_batch.sequence;
+  }
+  return result;
+}
+
+uint64_t rocksdb_get_latest_sequence_number (rocksdb_t *db) {
+    return db->rep->GetLatestSequenceNumber();
+}
+
 rocksdb_iterator_t* rocksdb_create_iterator_cf(
    rocksdb_t* db,
    const rocksdb_readoptions_t* options,
@@ -2520,8 +2576,9 @@ char *rocksdb_options_statistics_get_string(rocksdb_options_t *opt) {
 }

 void rocksdb_options_set_ratelimiter(rocksdb_options_t *opt, rocksdb_ratelimiter_t *limiter) {
-  opt->rep.rate_limiter.reset(limiter->rep);
-  limiter->rep = nullptr;
+  if (limiter) {
+    opt->rep.rate_limiter = limiter->rep;
+  }
 }

 rocksdb_ratelimiter_t* rocksdb_ratelimiter_create(
@@ -2529,18 +2586,186 @@ rocksdb_ratelimiter_t* rocksdb_ratelimiter_create(
    int64_t refill_period_us,
    int32_t fairness) {
  rocksdb_ratelimiter_t* rate_limiter = new rocksdb_ratelimiter_t;
-  rate_limiter->rep = NewGenericRateLimiter(rate_bytes_per_sec,
-                                            refill_period_us, fairness);
+  rate_limiter->rep.reset(
+               NewGenericRateLimiter(rate_bytes_per_sec,
+                                     refill_period_us, fairness));
  return rate_limiter;
 }

 void rocksdb_ratelimiter_destroy(rocksdb_ratelimiter_t *limiter) {
-  if (limiter->rep) {
-    delete limiter->rep;
-  }
  delete limiter;
 }

+void rocksdb_set_perf_level(int v) {
+  PerfLevel level = static_cast<PerfLevel>(v);
+  SetPerfLevel(level);
+}
+
+rocksdb_perfcontext_t* rocksdb_perfcontext_create() {
+  rocksdb_perfcontext_t* context = new rocksdb_perfcontext_t;
+  context->rep = rocksdb::get_perf_context();
+  return context;
+}
+
+void rocksdb_perfcontext_reset(rocksdb_perfcontext_t* context) {
+  context->rep->Reset();
+}
+
+char* rocksdb_perfcontext_report(rocksdb_perfcontext_t* context,
+    unsigned char exclude_zero_counters) {
+  return strdup(context->rep->ToString(exclude_zero_counters).c_str());
+}
+
+uint64_t rocksdb_perfcontext_metric(rocksdb_perfcontext_t* context,
+    int metric) {
+  PerfContext* rep = context->rep;
+  switch (metric) {
+    case rocksdb_user_key_comparison_count:
+      return rep->user_key_comparison_count;
+    case rocksdb_block_cache_hit_count:
+      return rep->block_cache_hit_count;
+    case rocksdb_block_read_count:
+      return rep->block_read_count;
+    case rocksdb_block_read_byte:
+      return rep->block_read_byte;
+    case rocksdb_block_read_time:
+      return rep->block_read_time;
+    case rocksdb_block_checksum_time:
+      return rep->block_checksum_time;
+    case rocksdb_block_decompress_time:
+      return rep->block_decompress_time;
+    case rocksdb_get_read_bytes:
+      return rep->get_read_bytes;
+    case rocksdb_multiget_read_bytes:
+      return rep->multiget_read_bytes;
+    case rocksdb_iter_read_bytes:
+      return rep->iter_read_bytes;
+    case rocksdb_internal_key_skipped_count:
+      return rep->internal_key_skipped_count;
+    case rocksdb_internal_delete_skipped_count:
+      return rep->internal_delete_skipped_count;
+    case rocksdb_internal_recent_skipped_count:
+      return rep->internal_recent_skipped_count;
+    case rocksdb_internal_merge_count:
+      return rep->internal_merge_count;
+    case rocksdb_get_snapshot_time:
+      return rep->get_snapshot_time;
+    case rocksdb_get_from_memtable_time:
+      return rep->get_from_memtable_time;
+    case rocksdb_get_from_memtable_count:
+      return rep->get_from_memtable_count;
+    case rocksdb_get_post_process_time:
+      return rep->get_post_process_time;
+    case rocksdb_get_from_output_files_time:
+      return rep->get_from_output_files_time;
+    case rocksdb_seek_on_memtable_time:
+      return rep->seek_on_memtable_time;
+    case rocksdb_seek_on_memtable_count:
+      return rep->seek_on_memtable_count;
+    case rocksdb_next_on_memtable_count:
+      return rep->next_on_memtable_count;
+    case rocksdb_prev_on_memtable_count:
+      return rep->prev_on_memtable_count;
+    case rocksdb_seek_child_seek_time:
+      return rep->seek_child_seek_time;
+    case rocksdb_seek_child_seek_count:
+      return rep->seek_child_seek_count;
+    case rocksdb_seek_min_heap_time:
+      return rep->seek_min_heap_time;
+    case rocksdb_seek_max_heap_time:
+      return rep->seek_max_heap_time;
+    case rocksdb_seek_internal_seek_time:
+      return rep->seek_internal_seek_time;
+    case rocksdb_find_next_user_entry_time:
+      return rep->find_next_user_entry_time;
+    case rocksdb_write_wal_time:
+      return rep->write_wal_time;
+    case rocksdb_write_memtable_time:
+      return rep->write_memtable_time;
+    case rocksdb_write_delay_time:
+      return rep->write_delay_time;
+    case rocksdb_write_pre_and_post_process_time:
+      return rep->write_pre_and_post_process_time;
+    case rocksdb_db_mutex_lock_nanos:
+      return rep->db_mutex_lock_nanos;
+    case rocksdb_db_condition_wait_nanos:
+      return rep->db_condition_wait_nanos;
+    case rocksdb_merge_operator_time_nanos:
+      return rep->merge_operator_time_nanos;
+    case rocksdb_read_index_block_nanos:
+      return rep->read_index_block_nanos;
+    case rocksdb_read_filter_block_nanos:
+      return rep->read_filter_block_nanos;
+    case rocksdb_new_table_block_iter_nanos:
+      return rep->new_table_block_iter_nanos;
+    case rocksdb_new_table_iterator_nanos:
+      return rep->new_table_iterator_nanos;
+    case rocksdb_block_seek_nanos:
+      return rep->block_seek_nanos;
+    case rocksdb_find_table_nanos:
+      return rep->find_table_nanos;
+    case rocksdb_bloom_memtable_hit_count:
+      return rep->bloom_memtable_hit_count;
+    case rocksdb_bloom_memtable_miss_count:
+      return rep->bloom_memtable_miss_count;
+    case rocksdb_bloom_sst_hit_count:
+      return rep->bloom_sst_hit_count;
+    case rocksdb_bloom_sst_miss_count:
+      return rep->bloom_sst_miss_count;
+    case rocksdb_key_lock_wait_time:
+      return rep->key_lock_wait_time;
+    case rocksdb_key_lock_wait_count:
+      return rep->key_lock_wait_count;
+    case rocksdb_env_new_sequential_file_nanos:
+      return rep->env_new_sequential_file_nanos;
+    case rocksdb_env_new_random_access_file_nanos:
+      return rep->env_new_random_access_file_nanos;
+    case rocksdb_env_new_writable_file_nanos:
+      return rep->env_new_writable_file_nanos;
+    case rocksdb_env_reuse_writable_file_nanos:
+      return rep->env_reuse_writable_file_nanos;
+    case rocksdb_env_new_random_rw_file_nanos:
+      return rep->env_new_random_rw_file_nanos;
+    case rocksdb_env_new_directory_nanos:
+      return rep->env_new_directory_nanos;
+    case rocksdb_env_file_exists_nanos:
+      return rep->env_file_exists_nanos;
+    case rocksdb_env_get_children_nanos:
+      return rep->env_get_children_nanos;
+    case rocksdb_env_get_children_file_attributes_nanos:
+      return rep->env_get_children_file_attributes_nanos;
+    case rocksdb_env_delete_file_nanos:
+      return rep->env_delete_file_nanos;
+    case rocksdb_env_create_dir_nanos:
+      return rep->env_create_dir_nanos;
+    case rocksdb_env_create_dir_if_missing_nanos:
+      return rep->env_create_dir_if_missing_nanos;
+    case rocksdb_env_delete_dir_nanos:
+      return rep->env_delete_dir_nanos;
+    case rocksdb_env_get_file_size_nanos:
+      return rep->env_get_file_size_nanos;
+    case rocksdb_env_get_file_modification_time_nanos:
+      return rep->env_get_file_modification_time_nanos;
+    case rocksdb_env_rename_file_nanos:
+      return rep->env_rename_file_nanos;
+    case rocksdb_env_link_file_nanos:
+      return rep->env_link_file_nanos;
+    case rocksdb_env_lock_file_nanos:
+      return rep->env_lock_file_nanos;
+    case rocksdb_env_unlock_file_nanos:
+      return rep->env_unlock_file_nanos;
+    case rocksdb_env_new_logger_nanos:
+      return rep->env_new_logger_nanos;
+    default:
+      break;
+  }
+  return 0;
+}
+
+void rocksdb_perfcontext_destroy(rocksdb_perfcontext_t* context) {
+  delete context;
+}
+
 /*
 TODO:
 DB::OpenForReadOnly
@@ -192,10 +192,11 @@ static void CheckDel(void* ptr, const char* k, size_t klen) {
  (*state)++;
 }

-static void CmpDestroy(void* arg) { }
+static void CmpDestroy(void* arg) { (void)arg; }

 static int CmpCompare(void* arg, const char* a, size_t alen,
                      const char* b, size_t blen) {
+  (void)arg;
  size_t n = (alen < blen) ? alen : blen;
  int r = memcmp(a, b, n);
  if (r == 0) {
@@ -206,13 +207,15 @@ static int CmpCompare(void* arg, const char* a, size_t alen,
 }

 static const char* CmpName(void* arg) {
+  (void)arg;
  return "foo";
 }

 // Custom filter policy
 static unsigned char fake_filter_result = 1;
-static void FilterDestroy(void* arg) { }
+static void FilterDestroy(void* arg) { (void)arg; }
 static const char* FilterName(void* arg) {
+  (void)arg;
  return "TestFilter";
 }
 static char* FilterCreate(
@@ -220,6 +223,10 @@ static char* FilterCreate(
    const char* const* key_array, const size_t* key_length_array,
    int num_keys,
    size_t* filter_length) {
+  (void)arg;
+  (void)key_array;
+  (void)key_length_array;
+  (void)num_keys;
  *filter_length = 4;
  char* result = malloc(4);
  memcpy(result, "fake", 4);
@@ -229,20 +236,30 @@ static unsigned char FilterKeyMatch(
    void* arg,
    const char* key, size_t length,
    const char* filter, size_t filter_length) {
+  (void)arg;
+  (void)key;
+  (void)length;
  CheckCondition(filter_length == 4);
  CheckCondition(memcmp(filter, "fake", 4) == 0);
  return fake_filter_result;
 }

 // Custom compaction filter
-static void CFilterDestroy(void* arg) {}
-static const char* CFilterName(void* arg) { return "foo"; }
+static void CFilterDestroy(void* arg) { (void)arg; }
+static const char* CFilterName(void* arg) {
+  (void)arg;
+  return "foo";
+}
 static unsigned char CFilterFilter(void* arg, int level, const char* key,
                                   size_t key_length,
                                   const char* existing_value,
                                   size_t value_length, char** new_value,
                                   size_t* new_value_length,
                                   unsigned char* value_changed) {
+  (void)arg;
+  (void)level;
+  (void)existing_value;
+  (void)value_length;
  if (key_length == 3) {
    if (memcmp(key, "bar", key_length) == 0) {
      return 1;
@@ -256,10 +273,15 @@ static unsigned char CFilterFilter(void* arg, int level, const char* key,
  return 0;
 }

-static void CFilterFactoryDestroy(void* arg) {}
-static const char* CFilterFactoryName(void* arg) { return "foo"; }
+static void CFilterFactoryDestroy(void* arg) { (void)arg; }
+static const char* CFilterFactoryName(void* arg) {
+  (void)arg;
+  return "foo";
+}
 static rocksdb_compactionfilter_t* CFilterCreate(
    void* arg, rocksdb_compactionfiltercontext_t* context) {
+  (void)arg;
+  (void)context;
  return rocksdb_compactionfilter_create(NULL, CFilterDestroy, CFilterFilter,
                                         CFilterName);
 }
@@ -290,8 +312,9 @@ static rocksdb_t* CheckCompaction(rocksdb_t* db, rocksdb_options_t* options,
 }

 // Custom merge operator
-static void MergeOperatorDestroy(void* arg) { }
+static void MergeOperatorDestroy(void* arg) { (void)arg; }
 static const char* MergeOperatorName(void* arg) {
+  (void)arg;
  return "TestMergeOperator";
 }
 static char* MergeOperatorFullMerge(
@@ -301,6 +324,14 @@ static char* MergeOperatorFullMerge(
    const char* const* operands_list, const size_t* operands_list_length,
    int num_operands,
    unsigned char* success, size_t* new_value_length) {
+  (void)arg;
+  (void)key;
+  (void)key_length;
+  (void)existing_value;
+  (void)existing_value_length;
+  (void)operands_list;
+  (void)operands_list_length;
+  (void)num_operands;
  *new_value_length = 4;
  *success = 1;
  char* result = malloc(4);
@@ -313,6 +344,12 @@ static char* MergeOperatorPartialMerge(
    const char* const* operands_list, const size_t* operands_list_length,
    int num_operands,
    unsigned char* success, size_t* new_value_length) {
+  (void)arg;
+  (void)key;
+  (void)key_length;
+  (void)operands_list;
+  (void)operands_list_length;
+  (void)num_operands;
  *new_value_length = 4;
  *success = 1;
  char* result = malloc(4);
@@ -377,6 +414,8 @@ static void CheckTxnDBGetCF(rocksdb_transactiondb_t* txn_db,
 }

 int main(int argc, char** argv) {
+  (void)argc;
+  (void)argv;
  rocksdb_t* db;
  rocksdb_comparator_t* cmp;
  rocksdb_cache_t* cache;
@@ -34,6 +34,7 @@
 #include "table/merging_iterator.h"
 #include "util/autovector.h"
 #include "util/compression.h"
+#include "util/sst_file_manager_impl.h"

 namespace rocksdb {

@@ -54,6 +55,9 @@ ColumnFamilyHandleImpl::~ColumnFamilyHandleImpl() {
 #endif  // ROCKSDB_LITE
    // Job id == 0 means that this is not our background process, but rather
    // user thread
+    // Need to hold some shared pointers owned by the initial_cf_options
+    // before final cleaning up finishes.
+    ColumnFamilyOptions initial_cf_options_copy = cfd_->initial_cf_options();
    JobContext job_context(0);
    mutex_->Lock();
    if (cfd_->Unref()) {
@@ -81,6 +85,7 @@ Status ColumnFamilyHandleImpl::GetDescriptor(ColumnFamilyDescriptor* desc) {
  *desc = ColumnFamilyDescriptor(cfd()->GetName(), cfd()->GetLatestCFOptions());
  return Status::OK();
 #else
+  (void)desc;
  return Status::NotSupported();
 #endif  // !ROCKSDB_LITE
 }
@@ -156,6 +161,28 @@ Status CheckConcurrentWritesSupported(const ColumnFamilyOptions& cf_options) {
  return Status::OK();
 }

+Status CheckCFPathsSupported(const DBOptions& db_options,
+                             const ColumnFamilyOptions& cf_options) {
+  // More than one cf_paths are supported only in universal
+  // and level compaction styles. This function also checks the case
+  // in which cf_paths is not specified, which results in db_paths
+  // being used.
+  if ((cf_options.compaction_style != kCompactionStyleUniversal) &&
+      (cf_options.compaction_style != kCompactionStyleLevel)) {
+    if (cf_options.cf_paths.size() > 1) {
+      return Status::NotSupported(
+          "More than one CF paths are only supported in "
+          "universal and level compaction styles. ");
+    } else if (cf_options.cf_paths.empty() &&
+               db_options.db_paths.size() > 1) {
+      return Status::NotSupported(
+          "More than one DB paths are only supported in "
+          "universal and level compaction styles. ");
+    }
+  }
+  return Status::OK();
+}
+
 ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
                                    const ColumnFamilyOptions& src) {
  ColumnFamilyOptions result = src;
@@ -274,9 +301,24 @@ ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
        result.hard_pending_compaction_bytes_limit;
  }

+#ifndef ROCKSDB_LITE
+  // When the DB is stopped, it's possible that there are some .trash files that
+  // were not deleted yet, when we open the DB we will find these .trash files
+  // and schedule them to be deleted (or delete immediately if SstFileManager
+  // was not used)
+  auto sfm = static_cast<SstFileManagerImpl*>(db_options.sst_file_manager.get());
+  for (size_t i = 0; i < result.cf_paths.size(); i++) {
+    DeleteScheduler::CleanupDirectory(db_options.env, sfm, result.cf_paths[i].path);
+  }
+#endif
+
+  if (result.cf_paths.empty()) {
+    result.cf_paths = db_options.db_paths;
+  }
+
  if (result.level_compaction_dynamic_level_bytes) {
    if (result.compaction_style != kCompactionStyleLevel ||
-        db_options.db_paths.size() > 1U) {
+        result.cf_paths.size() > 1U) {
      // 1. level_compaction_dynamic_level_bytes only makes sense for
      //    level-based compaction.
      // 2. we don't yet know how to make both of this feature and multiple
@@ -383,10 +425,10 @@ ColumnFamilyData::ColumnFamilyData(
      next_(nullptr),
      prev_(nullptr),
      log_number_(0),
-      flush_reason_(FlushReason::kUnknown),
+      flush_reason_(FlushReason::kOthers),
      column_family_set_(column_family_set),
-      pending_flush_(false),
-      pending_compaction_(false),
+      queued_for_flush_(false),
+      queued_for_compaction_(false),
      prev_compaction_needed_bytes_(0),
      allow_2pc_(db_options.allow_2pc),
      last_memtable_id_(0) {
@@ -462,8 +504,8 @@ ColumnFamilyData::~ColumnFamilyData() {

  // It would be wrong if this ColumnFamilyData is in flush_queue_ or
  // compaction_queue_ and we destroyed it
-  assert(!pending_flush_);
-  assert(!pending_compaction_);
+  assert(!queued_for_flush_);
+  assert(!queued_for_compaction_);

  if (super_version_ != nullptr) {
    // Release SuperVersion reference kept in ThreadLocalPtr.
@@ -516,7 +558,9 @@ uint64_t ColumnFamilyData::OldestLogToKeep() {
  auto current_log = GetLogNumber();

  if (allow_2pc_) {
-    auto imm_prep_log = imm()->GetMinLogContainingPrepSection();
+    autovector<MemTable*> empty_list;
+    auto imm_prep_log =
+        imm()->PrecomputeMinLogContainingPrepSection(empty_list);
    auto mem_prep_log = mem()->GetMinLogContainingPrepSection();

    if (imm_prep_log > 0 && imm_prep_log < current_log) {
@@ -953,11 +997,13 @@ const int ColumnFamilyData::kCompactToBaseLevel = -2;

 Compaction* ColumnFamilyData::CompactRange(
    const MutableCFOptions& mutable_cf_options, int input_level,
-    int output_level, uint32_t output_path_id, const InternalKey* begin,
-    const InternalKey* end, InternalKey** compaction_end, bool* conflict) {
+    int output_level, uint32_t output_path_id, uint32_t max_subcompactions,
+    const InternalKey* begin, const InternalKey* end,
+    InternalKey** compaction_end, bool* conflict) {
  auto* result = compaction_picker_->CompactRange(
      GetName(), mutable_cf_options, current_->storage_info(), input_level,
-      output_level, output_path_id, begin, end, compaction_end, conflict);
+      output_level, output_path_id, max_subcompactions, begin, end,
+      compaction_end, conflict);
  if (result != nullptr) {
    result->SetInputVersion(current_);
  }
@@ -1107,8 +1153,9 @@ void ColumnFamilyData::ResetThreadLocalSuperVersions() {
 Status ColumnFamilyData::SetOptions(
      const std::unordered_map<std::string, std::string>& options_map) {
  MutableCFOptions new_mutable_cf_options;
-  Status s = GetMutableOptionsFromStrings(mutable_cf_options_, options_map,
-                                          &new_mutable_cf_options);
+  Status s =
+      GetMutableOptionsFromStrings(mutable_cf_options_, options_map,
+                                   ioptions_.info_log, &new_mutable_cf_options);
  if (s.ok()) {
    mutable_cf_options_ = new_mutable_cf_options;
    mutable_cf_options_.RefreshDerivedOptions(ioptions_);
@@ -1135,6 +1182,31 @@ Env::WriteLifeTimeHint ColumnFamilyData::CalculateSSTWriteHint(int level) {
                            static_cast<int>(Env::WLTH_MEDIUM));
 }

+Status ColumnFamilyData::AddDirectories() {
+  Status s;
+  assert(data_dirs_.empty());
+  for (auto& p : ioptions_.cf_paths) {
+    std::unique_ptr<Directory> path_directory;
+    s = DBImpl::CreateAndNewDirectory(ioptions_.env, p.path, &path_directory);
+    if (!s.ok()) {
+      return s;
+    }
+    assert(path_directory != nullptr);
+    data_dirs_.emplace_back(path_directory.release());
+  }
+  assert(data_dirs_.size() == ioptions_.cf_paths.size());
+  return s;
+}
+
+Directory* ColumnFamilyData::GetDataDir(size_t path_id) const {
+  if (data_dirs_.empty()) {
+    return nullptr;
+  }
+
+  assert(path_id < data_dirs_.size());
+  return data_dirs_[path_id].get();
+}
+
 ColumnFamilySet::ColumnFamilySet(const std::string& dbname,
                                 const ImmutableDBOptions* db_options,
                                 const EnvOptions& env_options,
@@ -139,6 +139,9 @@ extern Status CheckCompressionSupported(const ColumnFamilyOptions& cf_options);
 extern Status CheckConcurrentWritesSupported(
    const ColumnFamilyOptions& cf_options);

+extern Status CheckCFPathsSupported(const DBOptions& db_options,
+                                    const ColumnFamilyOptions& cf_options);
+
 extern ColumnFamilyOptions SanitizeOptions(const ImmutableDBOptions& db_options,
                                           const ColumnFamilyOptions& src);
 // Wrap user defined table proproties collector factories `from cf_options`
@@ -293,9 +296,9 @@ class ColumnFamilyData {
  // REQUIRES: DB mutex held
  Compaction* CompactRange(const MutableCFOptions& mutable_cf_options,
                           int input_level, int output_level,
-                           uint32_t output_path_id, const InternalKey* begin,
-                           const InternalKey* end, InternalKey** compaction_end,
-                           bool* manual_conflict);
+                           uint32_t output_path_id, uint32_t max_subcompactions,
+                           const InternalKey* begin, const InternalKey* end,
+                           InternalKey** compaction_end, bool* manual_conflict);

  CompactionPicker* compaction_picker() { return compaction_picker_.get(); }
  // thread-safe
@@ -342,10 +345,10 @@ class ColumnFamilyData {
  void ResetThreadLocalSuperVersions();

  // Protected by DB mutex
-  void set_pending_flush(bool value) { pending_flush_ = value; }
-  void set_pending_compaction(bool value) { pending_compaction_ = value; }
-  bool pending_flush() { return pending_flush_; }
-  bool pending_compaction() { return pending_compaction_; }
+  void set_queued_for_flush(bool value) { queued_for_flush_ = value; }
+  void set_queued_for_compaction(bool value) { queued_for_compaction_ = value; }
+  bool queued_for_flush() { return queued_for_flush_; }
+  bool queued_for_compaction() { return queued_for_compaction_; }

  enum class WriteStallCause {
    kNone,
@@ -370,8 +373,16 @@ class ColumnFamilyData {

  bool initialized() const { return initialized_.load(); }

+  const ColumnFamilyOptions& initial_cf_options() {
+    return initial_cf_options_;
+  }
+
  Env::WriteLifeTimeHint CalculateSSTWriteHint(int level);

+  Status AddDirectories();
+
+  Directory* GetDataDir(size_t path_id) const;
+
 private:
  friend class ColumnFamilySet;
  ColumnFamilyData(uint32_t id, const std::string& name,
@@ -442,11 +453,11 @@ class ColumnFamilyData {
  std::unique_ptr<WriteControllerToken> write_controller_token_;

  // If true --> this ColumnFamily is currently present in DBImpl::flush_queue_
-  bool pending_flush_;
+  bool queued_for_flush_;

  // If true --> this ColumnFamily is currently present in
  // DBImpl::compaction_queue_
-  bool pending_compaction_;
+  bool queued_for_compaction_;

  uint64_t prev_compaction_needed_bytes_;

@@ -455,6 +466,9 @@ class ColumnFamilyData {

  // Memtable id to track flush.
  std::atomic<uint64_t> last_memtable_id_;
+
+  // Directories corresponding to cf_paths.
+  std::vector<std::unique_ptr<Directory>> data_dirs_;
 };

 // ColumnFamilySet has interesting thread-safety requirements
@@ -69,9 +69,15 @@ class ColumnFamilyTest : public testing::Test {
  }

  ~ColumnFamilyTest() {
+    std::vector<ColumnFamilyDescriptor> column_families;
+    for (auto h : handles_) {
+      ColumnFamilyDescriptor cfdescriptor;
+      h->GetDescriptor(&cfdescriptor);
+      column_families.push_back(cfdescriptor);
+    }
    Close();
    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
-    Destroy();
+    Destroy(column_families);
    delete env_;
  }

@@ -236,9 +242,11 @@ class ColumnFamilyTest : public testing::Test {
 #endif  // !ROCKSDB_LITE
  }

-  void Destroy() {
+  void Destroy(const std::vector<ColumnFamilyDescriptor>& column_families =
+                  std::vector<ColumnFamilyDescriptor>()) {
    Close();
-    ASSERT_OK(DestroyDB(dbname_, Options(db_options_, column_family_options_)));
+    ASSERT_OK(DestroyDB(dbname_, Options(db_options_, column_family_options_),
+                        column_families));
  }

  void CreateColumnFamilies(
@@ -291,6 +299,9 @@ class ColumnFamilyTest : public testing::Test {
  }

  void PutRandomData(int cf, int num, int key_value_size, bool save = false) {
+    if (cf >= static_cast<int>(keys_.size())) {
+      keys_.resize(cf + 1);
+    }
    for (int i = 0; i < num; ++i) {
      // 10 bytes for key, rest is value
      if (!save) {
@@ -298,7 +309,7 @@ class ColumnFamilyTest : public testing::Test {
                      RandomString(&rnd_, key_value_size - 10)));
      } else {
        std::string key = test::RandomKey(&rnd_, 11);
-        keys_.insert(key);
+        keys_[cf].insert(key);
        ASSERT_OK(Put(cf, key, RandomString(&rnd_, key_value_size - 10)));
      }
    }
@@ -490,9 +501,15 @@ class ColumnFamilyTest : public testing::Test {
    ASSERT_OK(destfile->Close());
  }

+  int GetSstFileCount(std::string path) {
+    std::vector<std::string> files;
+    DBTestBase::GetSstFiles(env_, path, &files);
+    return static_cast<int>(files.size());
+  }
+
  std::vector<ColumnFamilyHandle*> handles_;
  std::vector<std::string> names_;
-  std::set<std::string> keys_;
+  std::vector<std::set<std::string>> keys_;
  ColumnFamilyOptions column_family_options_;
  DBOptions db_options_;
  std::string dbname_;
@@ -1354,7 +1371,7 @@ TEST_F(ColumnFamilyTest, MultipleManualCompactions) {
       {"ColumnFamilyTest::MultiManual:2", "ColumnFamilyTest::MultiManual:5"},
       {"ColumnFamilyTest::MultiManual:2", "ColumnFamilyTest::MultiManual:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::MultiManual:4");
          cf_1_1 = false;
@@ -1400,8 +1417,8 @@ TEST_F(ColumnFamilyTest, MultipleManualCompactions) {
  CompactAll(2);
  AssertFilesPerLevel("0,1", 2);
  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1447,7 +1464,7 @@ TEST_F(ColumnFamilyTest, AutomaticAndManualCompactions) {
       {"ColumnFamilyTest::AutoManual:2", "ColumnFamilyTest::AutoManual:5"},
       {"ColumnFamilyTest::AutoManual:2", "ColumnFamilyTest::AutoManual:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          cf_1_1 = false;
          TEST_SYNC_POINT("ColumnFamilyTest::AutoManual:4");
@@ -1494,8 +1511,8 @@ TEST_F(ColumnFamilyTest, AutomaticAndManualCompactions) {
  CompactAll(2);
  AssertFilesPerLevel("0,1", 2);
  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1548,7 +1565,7 @@ TEST_F(ColumnFamilyTest, ManualAndAutomaticCompactions) {
       {"ColumnFamilyTest::ManualAuto:5", "ColumnFamilyTest::ManualAuto:2"},
       {"ColumnFamilyTest::ManualAuto:2", "ColumnFamilyTest::ManualAuto:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::ManualAuto:4");
          cf_1_1 = false;
@@ -1590,8 +1607,8 @@ TEST_F(ColumnFamilyTest, ManualAndAutomaticCompactions) {
  CompactAll(2);
  AssertFilesPerLevel("0,1", 2);
  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1641,7 +1658,7 @@ TEST_F(ColumnFamilyTest, SameCFManualManualCompactions) {
       {"ColumnFamilyTest::ManualManual:1",
        "ColumnFamilyTest::ManualManual:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::ManualManual:4");
          cf_1_1 = false;
@@ -1689,8 +1706,8 @@ TEST_F(ColumnFamilyTest, SameCFManualManualCompactions) {
  ASSERT_LE(NumTableFilesAtLevel(0, 1), 2);

  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1739,7 +1756,7 @@ TEST_F(ColumnFamilyTest, SameCFManualAutomaticCompactions) {
       {"ColumnFamilyTest::ManualAuto:1", "ColumnFamilyTest::ManualAuto:2"},
       {"ColumnFamilyTest::ManualAuto:1", "ColumnFamilyTest::ManualAuto:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::ManualAuto:4");
          cf_1_1 = false;
@@ -1779,8 +1796,8 @@ TEST_F(ColumnFamilyTest, SameCFManualAutomaticCompactions) {
  ASSERT_LE(NumTableFilesAtLevel(0, 1), 2);

  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1831,7 +1848,7 @@ TEST_F(ColumnFamilyTest, SameCFManualAutomaticCompactionsLevel) {
        "ColumnFamilyTest::ManualAuto:3"},
       {"ColumnFamilyTest::ManualAuto:1", "ColumnFamilyTest::ManualAuto:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::ManualAuto:4");
          cf_1_1 = false;
@@ -1869,8 +1886,8 @@ TEST_F(ColumnFamilyTest, SameCFManualAutomaticCompactionsLevel) {
  AssertFilesPerLevel("0,1", 1);

  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -1918,7 +1935,7 @@ TEST_F(ColumnFamilyTest, SameCFAutomaticManualCompactions) {
       {"CompactionPicker::CompactRange:Conflict",
        "ColumnFamilyTest::AutoManual:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (cf_1_1) {
          TEST_SYNC_POINT("ColumnFamilyTest::AutoManual:4");
          cf_1_1 = false;
@@ -1958,8 +1975,8 @@ TEST_F(ColumnFamilyTest, SameCFAutomaticManualCompactions) {
  // VERIFY compaction "one"
  AssertFilesPerLevel("1", 1);
  // Compare against saved keys
-  std::set<std::string>::iterator key_iter = keys_.begin();
-  while (key_iter != keys_.end()) {
+  std::set<std::string>::iterator key_iter = keys_[1].begin();
+  while (key_iter != keys_[1].end()) {
    ASSERT_NE("NOT_FOUND", Get(1, *key_iter));
    key_iter++;
  }
@@ -2365,7 +2382,7 @@ TEST_F(ColumnFamilyTest, CreateAndDropRace) {
  auto main_thread_id = std::this_thread::get_id();

  rocksdb::SyncPoint::GetInstance()->SetCallBack("PersistRocksDBOptions:start",
-                                                 [&](void* arg) {
+                                                 [&](void* /*arg*/) {
    auto current_thread_id = std::this_thread::get_id();
    // If it's the main thread hitting this sync-point, then it
    // will be blocked until some other thread update the test_stage.
@@ -2378,7 +2395,7 @@ TEST_F(ColumnFamilyTest, CreateAndDropRace) {
  });

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "WriteThread::EnterUnbatched:Wait", [&](void* arg) {
+      "WriteThread::EnterUnbatched:Wait", [&](void* /*arg*/) {
        // This means a thread doing DropColumnFamily() is waiting for
        // other thread to finish persisting options.
        // In such case, we update the test_stage to unblock the main thread.
@@ -2810,27 +2827,6 @@ TEST_F(ColumnFamilyTest, CreateAndDestoryOptions) {
  ASSERT_OK(db_->DestroyColumnFamilyHandle(cfh));
 }

-TEST_F(ColumnFamilyTest, CreateDropAndDestroy) {
-  ColumnFamilyHandle* cfh;
-  Open();
-  ASSERT_OK(db_->CreateColumnFamily(ColumnFamilyOptions(), "yoyo", &cfh));
-  ASSERT_OK(db_->Put(WriteOptions(), cfh, "foo", "bar"));
-  ASSERT_OK(db_->Flush(FlushOptions(), cfh));
-  ASSERT_OK(db_->DropColumnFamily(cfh));
-  ASSERT_OK(db_->DestroyColumnFamilyHandle(cfh));
-}
-
-TEST_F(ColumnFamilyTest, CreateDropAndDestroyWithoutFileDeletion) {
-  ColumnFamilyHandle* cfh;
-  Open();
-  ASSERT_OK(db_->CreateColumnFamily(ColumnFamilyOptions(), "yoyo", &cfh));
-  ASSERT_OK(db_->Put(WriteOptions(), cfh, "foo", "bar"));
-  ASSERT_OK(db_->Flush(FlushOptions(), cfh));
-  ASSERT_OK(db_->DisableFileDeletions());
-  ASSERT_OK(db_->DropColumnFamily(cfh));
-  ASSERT_OK(db_->DestroyColumnFamilyHandle(cfh));
-}
-
 #ifndef ROCKSDB_LITE
 TEST_F(ColumnFamilyTest, FlushCloseWALFiles) {
  SpecialEnv env(Env::Default());
@@ -3157,6 +3153,77 @@ TEST_F(ColumnFamilyTest, DISABLED_LogTruncationTest) {
  // cleanup
  env_->DeleteDir(backup_logs);
 }
+
+TEST_F(ColumnFamilyTest, DefaultCfPathsTest) {
+  Open();
+  // Leave cf_paths for one column families to be empty.
+  // Files should be generated according to db_paths for that
+  // column family.
+  ColumnFamilyOptions cf_opt1, cf_opt2;
+  cf_opt1.cf_paths.emplace_back(dbname_ + "_one_1",
+                                std::numeric_limits<uint64_t>::max());
+  CreateColumnFamilies({"one", "two"}, {cf_opt1, cf_opt2});
+  Reopen({ColumnFamilyOptions(), cf_opt1, cf_opt2});
+
+  // Fill Column family 1.
+  PutRandomData(1, 100, 100);
+  Flush(1);
+
+  ASSERT_EQ(1, GetSstFileCount(cf_opt1.cf_paths[0].path));
+  ASSERT_EQ(0, GetSstFileCount(dbname_));
+
+  // Fill column family 2
+  PutRandomData(2, 100, 100);
+  Flush(2);
+
+  // SST from Column family 2 should be generated in
+  // db_paths which is dbname_ in this case.
+  ASSERT_EQ(1, GetSstFileCount(dbname_));
+}
+
+TEST_F(ColumnFamilyTest, MultipleCFPathsTest) {
+  Open();
+  // Configure Column family specific paths.
+  ColumnFamilyOptions cf_opt1, cf_opt2;
+  cf_opt1.cf_paths.emplace_back(dbname_ + "_one_1",
+                                std::numeric_limits<uint64_t>::max());
+  cf_opt2.cf_paths.emplace_back(dbname_ + "_two_1",
+                                std::numeric_limits<uint64_t>::max());
+  CreateColumnFamilies({"one", "two"}, {cf_opt1, cf_opt2});
+  Reopen({ColumnFamilyOptions(), cf_opt1, cf_opt2});
+
+  PutRandomData(1, 100, 100, true /* save */);
+  Flush(1);
+
+  // Check that files are generated in appropriate paths.
+  ASSERT_EQ(1, GetSstFileCount(cf_opt1.cf_paths[0].path));
+  ASSERT_EQ(0, GetSstFileCount(dbname_));
+
+  PutRandomData(2, 100, 100, true /* save */);
+  Flush(2);
+
+  ASSERT_EQ(1, GetSstFileCount(cf_opt2.cf_paths[0].path));
+  ASSERT_EQ(0, GetSstFileCount(dbname_));
+
+  // Re-open and verify the keys.
+  Reopen({ColumnFamilyOptions(), cf_opt1, cf_opt2});
+  DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
+  for (int cf = 1; cf != 3; ++cf) {
+    ReadOptions read_options;
+    read_options.readahead_size = 0;
+    auto it = dbi->NewIterator(read_options, handles_[cf]);
+    for (it->SeekToFirst(); it->Valid(); it->Next()) {
+      Slice key(it->key());
+      ASSERT_NE(keys_[cf].end(), keys_[cf].find(key.ToString()));
+    }
+    delete it;
+
+    for (const auto& key : keys_[cf]) {
+      ASSERT_NE("NOT_FOUND", Get(cf, key));
+    }
+  }
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -49,8 +49,8 @@ Status CompactedDBImpl::Get(const ReadOptions& options, ColumnFamilyHandle*,
                         GetContext::kNotFound, key, value, nullptr, nullptr,
                         nullptr, nullptr);
  LookupKey lkey(key, kMaxSequenceNumber);
-  files_.files[FindFile(key)].fd.table_reader->Get(
-      options, lkey.internal_key(), &get_context);
+  files_.files[FindFile(key)].fd.table_reader->Get(options, lkey.internal_key(),
+                                                   &get_context, nullptr);
  if (get_context.State() == GetContext::kFound) {
    return Status::OK();
  }
@@ -82,7 +82,7 @@ std::vector<Status> CompactedDBImpl::MultiGet(const ReadOptions& options,
                             GetContext::kNotFound, keys[idx], &pinnable_val,
                             nullptr, nullptr, nullptr, nullptr);
      LookupKey lkey(keys[idx], kMaxSequenceNumber);
-      r->Get(options, lkey.internal_key(), &get_context);
+      r->Get(options, lkey.internal_key(), &get_context, nullptr);
      value.assign(pinnable_val.data(), pinnable_val.size());
      if (get_context.State() == GetContext::kFound) {
        statuses[idx] = Status::OK();
@@ -134,6 +134,7 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
                       int _output_level, uint64_t _target_file_size,
                       uint64_t _max_compaction_bytes, uint32_t _output_path_id,
                       CompressionType _compression,
+                       uint32_t _max_subcompactions,
                       std::vector<FileMetaData*> _grandparents,
                       bool _manual_compaction, double _score,
                       bool _deletion_compaction,
@@ -143,6 +144,7 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
      output_level_(_output_level),
      max_output_file_size_(_target_file_size),
      max_compaction_bytes_(_max_compaction_bytes),
+      max_subcompactions_(_max_subcompactions),
      immutable_cf_options_(_immutable_cf_options),
      mutable_cf_options_(_mutable_cf_options),
      input_version_(nullptr),
@@ -163,6 +165,9 @@ Compaction::Compaction(VersionStorageInfo* vstorage,
  if (is_manual_compaction_) {
    compaction_reason_ = CompactionReason::kManualCompaction;
  }
+  if (max_subcompactions_ == 0) {
+    max_subcompactions_ = immutable_cf_options_.max_subcompactions;
+  }

 #ifndef NDEBUG
  for (size_t i = 1; i < inputs_.size(); ++i) {
@@ -442,7 +447,7 @@ bool Compaction::IsOutputLevelEmpty() const {
 }

 bool Compaction::ShouldFormSubcompactions() const {
-  if (immutable_cf_options_.max_subcompactions <= 1 || cfd_ == nullptr) {
+  if (max_subcompactions_ <= 1 || cfd_ == nullptr) {
    return false;
  }
  if (cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
@@ -468,4 +473,8 @@ uint64_t Compaction::MaxInputFileCreationTime() const {
  return max_creation_time;
 }

+int Compaction::GetInputBaseLevel() const {
+  return input_vstorage_->base_level();
+}
+
 }  // namespace rocksdb
@@ -40,6 +40,7 @@ class Compaction {
             std::vector<CompactionInputFiles> inputs, int output_level,
             uint64_t target_file_size, uint64_t max_compaction_bytes,
             uint32_t output_path_id, CompressionType compression,
+             uint32_t max_subcompactions,
             std::vector<FileMetaData*> grandparents,
             bool manual_compaction = false, double score = -1,
             bool deletion_compaction = false,
@@ -233,6 +234,8 @@ class Compaction {

  Slice GetLargestUserKey() const { return largest_user_key_; }

+  int GetInputBaseLevel() const;
+
  CompactionReason compaction_reason() { return compaction_reason_; }

  const std::vector<FileMetaData*>& grandparents() const {
@@ -241,6 +244,8 @@ class Compaction {

  uint64_t max_compaction_bytes() const { return max_compaction_bytes_; }

+  uint32_t max_subcompactions() const { return max_subcompactions_; }
+
  uint64_t MaxInputFileCreationTime() const;

 private:
@@ -267,6 +272,7 @@ class Compaction {
  const int output_level_;  // levels to which output files are stored
  uint64_t max_output_file_size_;
  uint64_t max_compaction_bytes_;
+  uint32_t max_subcompactions_;
  const ImmutableCFOptions immutable_cf_options_;
  const MutableCFOptions mutable_cf_options_;
  Version* input_version_;
@@ -62,6 +62,46 @@

 namespace rocksdb {

+const char* GetCompactionReasonString(CompactionReason compaction_reason) {
+  switch (compaction_reason) {
+    case CompactionReason::kUnknown:
+      return "Unknown";
+    case CompactionReason::kLevelL0FilesNum:
+      return "LevelL0FilesNum";
+    case CompactionReason::kLevelMaxLevelSize:
+      return "LevelMaxLevelSize";
+    case CompactionReason::kUniversalSizeAmplification:
+      return "UniversalSizeAmplification";
+    case CompactionReason::kUniversalSizeRatio:
+      return "UniversalSizeRatio";
+    case CompactionReason::kUniversalSortedRunNum:
+      return "UniversalSortedRunNum";
+    case CompactionReason::kFIFOMaxSize:
+      return "FIFOMaxSize";
+    case CompactionReason::kFIFOReduceNumFiles:
+      return "FIFOReduceNumFiles";
+    case CompactionReason::kFIFOTtl:
+      return "FIFOTtl";
+    case CompactionReason::kManualCompaction:
+      return "ManualCompaction";
+    case CompactionReason::kFilesMarkedForCompaction:
+      return "FilesMarkedForCompaction";
+    case CompactionReason::kBottommostFiles:
+      return "BottommostFiles";
+    case CompactionReason::kTtl:
+      return "Ttl";
+    case CompactionReason::kFlush:
+      return "Flush";
+    case CompactionReason::kExternalSstIngestion:
+      return "ExternalSstIngestion";
+    case CompactionReason::kNumOfReasons:
+      // fall through
+    default:
+      assert(false);
+      return "Invalid";
+  }
+}
+
 // Maintains state for each sub-compaction
 struct CompactionJob::SubcompactionState {
  const Compaction* compaction;
@@ -276,7 +316,7 @@ CompactionJob::CompactionJob(
    : job_id_(job_id),
      compact_(new CompactionState(compaction)),
      compaction_job_stats_(compaction_job_stats),
-      compaction_stats_(1),
+      compaction_stats_(compaction->compaction_reason(), 1),
      dbname_(dbname),
      db_options_(db_options),
      env_options_(env_options),
@@ -314,15 +354,13 @@ CompactionJob::~CompactionJob() {
  ThreadStatusUtil::ResetThreadStatus();
 }

-void CompactionJob::ReportStartedCompaction(
-    Compaction* compaction) {
+void CompactionJob::ReportStartedCompaction(Compaction* compaction) {
  const auto* cfd = compact_->compaction->column_family_data();
  ThreadStatusUtil::SetColumnFamily(cfd, cfd->ioptions()->env,
                                    db_options_.enable_thread_tracking);

-  ThreadStatusUtil::SetThreadOperationProperty(
-      ThreadStatus::COMPACTION_JOB_ID,
-      job_id_);
+  ThreadStatusUtil::SetThreadOperationProperty(ThreadStatus::COMPACTION_JOB_ID,
+                                               job_id_);

  ThreadStatusUtil::SetThreadOperationProperty(
      ThreadStatus::COMPACTION_INPUT_OUTPUT_LEVEL,
@@ -352,8 +390,7 @@ void CompactionJob::ReportStartedCompaction(

  // Set the thread operation after operation properties
  // to ensure GetThreadList() can always show them all together.
-  ThreadStatusUtil::SetThreadOperation(
-      ThreadStatus::OP_COMPACTION);
+  ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION);

  if (compaction_job_stats_) {
    compaction_job_stats_->is_manual_compaction =
@@ -368,11 +405,11 @@ void CompactionJob::Prepare() {
  // Generate file_levels_ for compaction berfore making Iterator
  auto* c = compact_->compaction;
  assert(c->column_family_data() != nullptr);
-  assert(c->column_family_data()->current()->storage_info()
-      ->NumLevelFiles(compact_->compaction->level()) > 0);
+  assert(c->column_family_data()->current()->storage_info()->NumLevelFiles(
+             compact_->compaction->level()) > 0);

-  write_hint_ = c->column_family_data()->CalculateSSTWriteHint(
-    c->output_level());
+  write_hint_ =
+      c->column_family_data()->CalculateSSTWriteHint(c->output_level());
  // Is this compaction producing files at the bottommost level?
  bottommost_level_ = c->bottommost_level();

@@ -455,14 +492,18 @@ void CompactionJob::GenSubcompactionBoundaries() {
  }

  std::sort(bounds.begin(), bounds.end(),
-    [cfd_comparator] (const Slice& a, const Slice& b) -> bool {
-      return cfd_comparator->Compare(ExtractUserKey(a), ExtractUserKey(b)) < 0;
-    });
+            [cfd_comparator](const Slice& a, const Slice& b) -> bool {
+              return cfd_comparator->Compare(ExtractUserKey(a),
+                                             ExtractUserKey(b)) < 0;
+            });
  // Remove duplicated entries from bounds
-  bounds.erase(std::unique(bounds.begin(), bounds.end(),
-    [cfd_comparator] (const Slice& a, const Slice& b) -> bool {
-      return cfd_comparator->Compare(ExtractUserKey(a), ExtractUserKey(b)) == 0;
-    }), bounds.end());
+  bounds.erase(
+      std::unique(bounds.begin(), bounds.end(),
+                  [cfd_comparator](const Slice& a, const Slice& b) -> bool {
+                    return cfd_comparator->Compare(ExtractUserKey(a),
+                                                   ExtractUserKey(b)) == 0;
+                  }),
+      bounds.end());

  // Combine consecutive pairs of boundaries into ranges with an approximate
  // size of data covered by keys in that range
@@ -485,12 +526,15 @@ void CompactionJob::GenSubcompactionBoundaries() {

  // Group the ranges into subcompactions
  const double min_file_fill_percent = 4.0 / 5;
-  uint64_t max_output_files = static_cast<uint64_t>(
-      std::ceil(sum / min_file_fill_percent /
-                c->mutable_cf_options()->MaxFileSizeForLevel(out_lvl)));
+  int base_level = v->storage_info()->base_level();
+  uint64_t max_output_files = static_cast<uint64_t>(std::ceil(
+      sum / min_file_fill_percent /
+      MaxFileSizeForLevel(*(c->mutable_cf_options()), out_lvl,
+          c->immutable_cf_options()->compaction_style, base_level,
+          c->immutable_cf_options()->level_compaction_dynamic_level_bytes)));
  uint64_t subcompactions =
      std::min({static_cast<uint64_t>(ranges.size()),
-                static_cast<uint64_t>(db_options_.max_subcompactions),
+                static_cast<uint64_t>(c->max_subcompactions()),
                max_output_files});

  if (subcompactions > 1) {
@@ -566,8 +610,9 @@ Status CompactionJob::Run() {
  TablePropertiesCollection tp;
  for (const auto& state : compact_->sub_compact_states) {
    for (const auto& output : state.outputs) {
-      auto fn = TableFileName(db_options_.db_paths, output.meta.fd.GetNumber(),
-                              output.meta.fd.GetPathId());
+      auto fn =
+          TableFileName(state.compaction->immutable_cf_options()->cf_paths,
+                        output.meta.fd.GetNumber(), output.meta.fd.GetPathId());
      tp[fn] = output.table_properties;
    }
  }
@@ -723,15 +768,18 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
  std::set<size_t> sample_begin_offsets;
  if (bottommost_level_ && kSampleBytes > 0) {
    const size_t kMaxSamples = kSampleBytes >> kSampleLenShift;
-    const size_t kOutFileLen = static_cast<size_t>(
-      mutable_cf_options->MaxFileSizeForLevel(
-        compact_->compaction->output_level()));
+    const size_t kOutFileLen =
+        static_cast<size_t>(MaxFileSizeForLevel(*mutable_cf_options,
+            compact_->compaction->output_level(),
+            cfd->ioptions()->compaction_style,
+            compact_->compaction->GetInputBaseLevel(),
+            cfd->ioptions()->level_compaction_dynamic_level_bytes));
    if (kOutFileLen != port::kMaxSizet) {
      const size_t kOutFileNumSamples = kOutFileLen >> kSampleLenShift;
      Random64 generator{versions_->NewFileNumber()};
      for (size_t i = 0; i < kMaxSamples; ++i) {
        sample_begin_offsets.insert(
-          static_cast<size_t>(generator.Uniform(kOutFileNumSamples))
+            static_cast<size_t>(generator.Uniform(kOutFileNumSamples))
            << kSampleLenShift);
      }
    }
@@ -773,13 +821,12 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
      preserve_deletes_seqnum_));
  auto c_iter = sub_compact->c_iter.get();
  c_iter->SeekToFirst();
-  if (c_iter->Valid() &&
-      sub_compact->compaction->output_level() != 0) {
+  if (c_iter->Valid() && sub_compact->compaction->output_level() != 0) {
    // ShouldStopBefore() maintains state based on keys processed so far. The
    // compaction loop always calls it on the "next" key, thus won't tell it the
    // first key. So we do that here.
-    sub_compact->ShouldStopBefore(
-      c_iter->key(), sub_compact->current_output_file_size);
+    sub_compact->ShouldStopBefore(c_iter->key(),
+                                  sub_compact->current_output_file_size);
  }
  const auto& c_iter_stats = c_iter->iter_stats();
  auto sample_begin_offset_iter = sample_begin_offsets.cbegin();
@@ -893,8 +940,8 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
    c_iter->Next();
    if (!output_file_ended && c_iter->Valid() &&
        sub_compact->compaction->output_level() != 0 &&
-        sub_compact->ShouldStopBefore(
-          c_iter->key(), sub_compact->current_output_file_size) &&
+        sub_compact->ShouldStopBefore(c_iter->key(),
+                                      sub_compact->current_output_file_size) &&
        sub_compact->builder != nullptr) {
      // (2) this key belongs to the next file. For historical reasons, the
      // iterator status after advancing will be given to
@@ -946,8 +993,8 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
  RecordDroppedKeys(c_iter_stats, &sub_compact->compaction_job_stats);
  RecordCompactionIOStats();

-  if (status.ok() && (shutting_down_->load(std::memory_order_relaxed) ||
-                      cfd->IsDropped())) {
+  if (status.ok() &&
+      (shutting_down_->load(std::memory_order_relaxed) || cfd->IsDropped())) {
    status = Status::ShutdownInProgress(
        "Database shutdown or Column family drop during compaction");
  }
@@ -1111,8 +1158,9 @@ Status CompactionJob::FinishCompactionOutputFile(
    // If there is nothing to output, no necessary to generate a sst file.
    // This happens when the output level is bottom level, at the same time
    // the sub_compact output nothing.
-    std::string fname = TableFileName(
-        db_options_.db_paths, meta->fd.GetNumber(), meta->fd.GetPathId());
+    std::string fname =
+        TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
+                      meta->fd.GetNumber(), meta->fd.GetPathId());
    env_->DeleteFile(fname);

    // Also need to remove the file from outputs, or it will be added to the
@@ -1131,11 +1179,13 @@ Status CompactionJob::FinishCompactionOutputFile(
    // We set for_compaction to false and don't OptimizeForCompactionTableRead
    // here because this is a special case after we finish the table building
    // No matter whether use_direct_io_for_flush_and_compaction is true,
-    // we will regrad this verification as user reads since the goal is
+    // we will regard this verification as user reads since the goal is
    // to cache it here for further user reads
    InternalIterator* iter = cfd->table_cache()->NewIterator(
        ReadOptions(), env_options_, cfd->internal_comparator(), meta->fd,
-        nullptr /* range_del_agg */, nullptr,
+        nullptr /* range_del_agg */,
+        sub_compact->compaction->mutable_cf_options()->prefix_extractor.get(),
+        nullptr,
        cfd->internal_stats()->GetFileReadHist(
            compact_->compaction->output_level()),
        false, nullptr /* arena */, false /* skip_filters */,
@@ -1143,7 +1193,8 @@ Status CompactionJob::FinishCompactionOutputFile(
    s = iter->status();

    if (s.ok() && paranoid_file_checks_) {
-      for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
+      for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+      }
      s = iter->status();
    }

@@ -1165,8 +1216,9 @@ Status CompactionJob::FinishCompactionOutputFile(
  std::string fname;
  FileDescriptor output_fd;
  if (meta != nullptr) {
-    fname = TableFileName(db_options_.db_paths, meta->fd.GetNumber(),
-                          meta->fd.GetPathId());
+    fname =
+        TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
+                      meta->fd.GetNumber(), meta->fd.GetPathId());
    output_fd = meta->fd;
  } else {
    fname = "(nil)";
@@ -1180,13 +1232,14 @@ Status CompactionJob::FinishCompactionOutputFile(
  auto sfm =
      static_cast<SstFileManagerImpl*>(db_options_.sst_file_manager.get());
  if (sfm && meta != nullptr && meta->fd.GetPathId() == 0) {
-    auto fn = TableFileName(cfd->ioptions()->db_paths, meta->fd.GetNumber(),
-                            meta->fd.GetPathId());
+    auto fn =
+        TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
+                      meta->fd.GetNumber(), meta->fd.GetPathId());
    sfm->OnAddFile(fn);
    if (sfm->IsMaxAllowedSpaceReached()) {
      // TODO(ajkr): should we return OK() if max space was reached by the final
      // compaction output file (similarly to how flush works when full)?
-      s = Status::IOError("Max allowed space was reached");
+      s = Status::NoSpace("Max allowed space was reached");
      TEST_SYNC_POINT(
          "CompactionJob::FinishCompactionOutputFile:"
          "MaxAllowedSpaceReached");
@@ -1236,7 +1289,7 @@ Status CompactionJob::InstallCompactionResults(
        compaction->InputLevelSummary(&inputs_summary), compact_->total_bytes);
  }

-  // Add compaction outputs
+  // Add compaction inputs
  compaction->AddInputDeletions(compact_->compaction->edit());

  for (const auto& sub_compact : compact_->sub_compact_states) {
@@ -1266,8 +1319,9 @@ Status CompactionJob::OpenCompactionOutputFile(
  assert(sub_compact->builder == nullptr);
  // no need to lock because VersionSet::next_file_number_ is atomic
  uint64_t file_number = versions_->NewFileNumber();
-  std::string fname = TableFileName(db_options_.db_paths, file_number,
-                                    sub_compact->compaction->output_path_id());
+  std::string fname =
+      TableFileName(sub_compact->compaction->immutable_cf_options()->cf_paths,
+                    file_number, sub_compact->compaction->output_path_id());
  // Fire events.
  ColumnFamilyData* cfd = sub_compact->compaction->column_family_data();
 #ifndef ROCKSDB_LITE
@@ -1334,9 +1388,10 @@ Status CompactionJob::OpenCompactionOutputFile(
  }

  sub_compact->builder.reset(NewTableBuilder(
-      *cfd->ioptions(), cfd->internal_comparator(),
-      cfd->int_tbl_prop_collector_factories(), cfd->GetID(), cfd->GetName(),
-      sub_compact->outfile.get(), sub_compact->compaction->output_compression(),
+      *cfd->ioptions(), *(sub_compact->compaction->mutable_cf_options()),
+      cfd->internal_comparator(), cfd->int_tbl_prop_collector_factories(),
+      cfd->GetID(), cfd->GetName(), sub_compact->outfile.get(),
+      sub_compact->compaction->output_compression(),
      cfd->ioptions()->compression_opts,
      sub_compact->compaction->output_level(), &sub_compact->compression_dict,
      skip_filters, output_file_creation_time));
@@ -1369,8 +1424,7 @@ void CompactionJob::CleanupCompaction() {

 #ifndef ROCKSDB_LITE
 namespace {
-void CopyPrefix(
-    const Slice& src, size_t prefix_length, std::string* dst) {
+void CopyPrefix(const Slice& src, size_t prefix_length, std::string* dst) {
  assert(prefix_length > 0);
  size_t length = src.size() > prefix_length ? prefix_length : src.size();
  dst->assign(src.data(), length);
@@ -1389,13 +1443,11 @@ void CompactionJob::UpdateCompactionStats() {
    if (compaction->level(input_level) != compaction->output_level()) {
      UpdateCompactionInputStatsHelper(
          &compaction_stats_.num_input_files_in_non_output_levels,
-          &compaction_stats_.bytes_read_non_output_levels,
-          input_level);
+          &compaction_stats_.bytes_read_non_output_levels, input_level);
    } else {
      UpdateCompactionInputStatsHelper(
          &compaction_stats_.num_input_files_in_output_level,
-          &compaction_stats_.bytes_read_output_level,
-          input_level);
+          &compaction_stats_.bytes_read_output_level, input_level);
    }
  }

@@ -1418,8 +1470,9 @@ void CompactionJob::UpdateCompactionStats() {
  }
 }

-void CompactionJob::UpdateCompactionInputStatsHelper(
-    int* num_files, uint64_t* bytes_read, int input_level) {
+void CompactionJob::UpdateCompactionInputStatsHelper(int* num_files,
+                                                     uint64_t* bytes_read,
+                                                     int input_level) {
  const Compaction* compaction = compact_->compaction;
  auto num_input_files = compaction->num_input_files(input_level);
  *num_files += static_cast<int>(num_input_files);
@@ -1440,10 +1493,8 @@ void CompactionJob::UpdateCompactionJobStats(

    // input information
    compaction_job_stats_->total_input_bytes =
-        stats.bytes_read_non_output_levels +
-        stats.bytes_read_output_level;
-    compaction_job_stats_->num_input_records =
-        compact_->num_input_records;
+        stats.bytes_read_non_output_levels + stats.bytes_read_output_level;
+    compaction_job_stats_->num_input_records = compact_->num_input_records;
    compaction_job_stats_->num_input_files =
        stats.num_input_files_in_non_output_levels +
        stats.num_input_files_in_output_level;
@@ -1452,21 +1503,20 @@ void CompactionJob::UpdateCompactionJobStats(

    // output information
    compaction_job_stats_->total_output_bytes = stats.bytes_written;
-    compaction_job_stats_->num_output_records =
-        compact_->num_output_records;
+    compaction_job_stats_->num_output_records = compact_->num_output_records;
    compaction_job_stats_->num_output_files = stats.num_output_files;

    if (compact_->NumOutputFiles() > 0U) {
-      CopyPrefix(
-          compact_->SmallestUserKey(),
-          CompactionJobStats::kMaxPrefixLength,
-          &compaction_job_stats_->smallest_output_key_prefix);
-      CopyPrefix(
-          compact_->LargestUserKey(),
-          CompactionJobStats::kMaxPrefixLength,
-          &compaction_job_stats_->largest_output_key_prefix);
+      CopyPrefix(compact_->SmallestUserKey(),
+                 CompactionJobStats::kMaxPrefixLength,
+                 &compaction_job_stats_->smallest_output_key_prefix);
+      CopyPrefix(compact_->LargestUserKey(),
+                 CompactionJobStats::kMaxPrefixLength,
+                 &compaction_job_stats_->largest_output_key_prefix);
    }
  }
+#else
+  (void)stats;
 #endif  // !ROCKSDB_LITE
 }

@@ -1489,7 +1539,9 @@ void CompactionJob::LogCompaction() {
    // build event logger report
    auto stream = event_logger_->Log();
    stream << "job" << job_id_ << "event"
-           << "compaction_started";
+           << "compaction_started"
+           << "compaction_reason"
+           << GetCompactionReasonString(compaction->compaction_reason());
    for (size_t i = 0; i < compaction->num_input_levels(); ++i) {
      stream << ("files_L" + ToString(compaction->level(i)));
      stream.StartArray();
@@ -30,6 +30,7 @@
 #include "db/write_controller.h"
 #include "db/write_thread.h"
 #include "options/db_options.h"
+#include "options/cf_options.h"
 #include "port/port.h"
 #include "rocksdb/compaction_filter.h"
 #include "rocksdb/compaction_job_stats.h"
@@ -806,7 +806,7 @@ TEST_P(CompactionJobStatsTest, CompactionJobStatsTest) {
    stats_checker->set_verify_next_comp_io_stats(true);
    std::atomic<bool> first_prepare_write(true);
    rocksdb::SyncPoint::GetInstance()->SetCallBack(
-        "WritableFileWriter::Append:BeforePrepareWrite", [&](void* arg) {
+        "WritableFileWriter::Append:BeforePrepareWrite", [&](void* /*arg*/) {
          if (first_prepare_write.load()) {
            options.env->SleepForMicroseconds(3);
            first_prepare_write.store(false);
@@ -815,7 +815,7 @@ TEST_P(CompactionJobStatsTest, CompactionJobStatsTest) {

    std::atomic<bool> first_flush(true);
    rocksdb::SyncPoint::GetInstance()->SetCallBack(
-        "WritableFileWriter::Flush:BeforeAppend", [&](void* arg) {
+        "WritableFileWriter::Flush:BeforeAppend", [&](void* /*arg*/) {
          if (first_flush.load()) {
            options.env->SleepForMicroseconds(3);
            first_flush.store(false);
@@ -824,7 +824,7 @@ TEST_P(CompactionJobStatsTest, CompactionJobStatsTest) {

    std::atomic<bool> first_sync(true);
    rocksdb::SyncPoint::GetInstance()->SetCallBack(
-        "WritableFileWriter::SyncInternal:0", [&](void* arg) {
+        "WritableFileWriter::SyncInternal:0", [&](void* /*arg*/) {
          if (first_sync.load()) {
            options.env->SleepForMicroseconds(3);
            first_sync.store(false);
@@ -833,7 +833,7 @@ TEST_P(CompactionJobStatsTest, CompactionJobStatsTest) {

    std::atomic<bool> first_range_sync(true);
    rocksdb::SyncPoint::GetInstance()->SetCallBack(
-        "WritableFileWriter::RangeSync:0", [&](void* arg) {
+        "WritableFileWriter::RangeSync:0", [&](void* /*arg*/) {
          if (first_range_sync.load()) {
            options.env->SleepForMicroseconds(3);
            first_range_sync.store(false);
@@ -246,7 +246,7 @@ class CompactionJobTest : public testing::Test {
    Compaction compaction(cfd->current()->storage_info(), *cfd->ioptions(),
                          *cfd->GetLatestMutableCFOptions(),
                          compaction_input_files, 1, 1024 * 1024,
-                          10 * 1024 * 1024, 0, kNoCompression, {}, true);
+                          10 * 1024 * 1024, 0, kNoCompression, 0, {}, true);
    compaction.SetInputVersion(cfd->current());

    LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, db_options_.info_log.get());
@@ -59,7 +59,7 @@ bool FindIntraL0Compaction(const std::vector<FileMetaData*>& level_files,
  }

  if (span_len >= min_files_to_compact &&
-      new_compact_bytes_per_del_file < max_compact_bytes_per_del_file) {
+      compact_bytes_per_del_file < max_compact_bytes_per_del_file) {
    assert(comp_inputs != nullptr);
    comp_inputs->level = 0;
    for (size_t i = 0; i < span_len; ++i) {
@@ -301,7 +301,9 @@ Compaction* CompactionPicker::CompactFiles(
      new Compaction(vstorage, ioptions_, mutable_cf_options, input_files,
                     output_level, compact_options.output_file_size_limit,
                     mutable_cf_options.max_compaction_bytes, output_path_id,
-                     compact_options.compression, /* grandparents */ {}, true);
+                     compact_options.compression,
+                     compact_options.max_subcompactions,
+                     /* grandparents */ {}, true);
  RegisterCompaction(c);
  return c;
 }
@@ -475,7 +477,7 @@ bool CompactionPicker::SetupOtherInputs(
      ROCKS_LOG_INFO(ioptions_.info_log,
                     "[%s] Expanding@%d %" ROCKSDB_PRIszt "+%" ROCKSDB_PRIszt
                     "(%" PRIu64 "+%" PRIu64 " bytes) to %" ROCKSDB_PRIszt
-                     "+%" ROCKSDB_PRIszt " (%" PRIu64 "+%" PRIu64 "bytes)\n",
+                     "+%" ROCKSDB_PRIszt " (%" PRIu64 "+%" PRIu64 " bytes)\n",
                     cf_name.c_str(), input_level, inputs->size(),
                     output_level_inputs->size(), inputs_size,
                     output_level_inputs_size, expanded_inputs.size(),
@@ -504,7 +506,8 @@ void CompactionPicker::GetGrandparents(
 Compaction* CompactionPicker::CompactRange(
    const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
    VersionStorageInfo* vstorage, int input_level, int output_level,
-    uint32_t output_path_id, const InternalKey* begin, const InternalKey* end,
+    uint32_t output_path_id, uint32_t max_subcompactions,
+    const InternalKey* begin, const InternalKey* end,
    InternalKey** compaction_end, bool* manual_conflict) {
  // CompactionPickerFIFO has its own implementation of compact range
  assert(ioptions_.compaction_style != kCompactionStyleFIFO);
@@ -566,11 +569,12 @@ Compaction* CompactionPicker::CompactRange(

    Compaction* c = new Compaction(
        vstorage, ioptions_, mutable_cf_options, std::move(inputs),
-        output_level, mutable_cf_options.MaxFileSizeForLevel(output_level),
+        output_level, MaxFileSizeForLevel(mutable_cf_options, output_level,
+            ioptions_.compaction_style),
        /* max_compaction_bytes */ LLONG_MAX, output_path_id,
        GetCompressionType(ioptions_, vstorage, mutable_cf_options,
                           output_level, 1),
-        /* grandparents */ {}, /* is manual */ true);
+        max_subcompactions, /* grandparents */ {}, /* is manual */ true);
    RegisterCompaction(c);
    return c;
  }
@@ -616,7 +620,7 @@ Compaction* CompactionPicker::CompactRange(
      }
    }
  }
-  assert(output_path_id < static_cast<uint32_t>(ioptions_.db_paths.size()));
+  assert(output_path_id < static_cast<uint32_t>(ioptions_.cf_paths.size()));

  if (ExpandInputsToCleanCut(cf_name, vstorage, &inputs) == false) {
    // manual compaction is now multi-threaded, so it can
@@ -673,11 +677,15 @@ Compaction* CompactionPicker::CompactRange(
  GetGrandparents(vstorage, inputs, output_level_inputs, &grandparents);
  Compaction* compaction = new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(compaction_inputs),
-      output_level, mutable_cf_options.MaxFileSizeForLevel(output_level),
+      output_level,
+      MaxFileSizeForLevel(mutable_cf_options, output_level,
+          ioptions_.compaction_style, vstorage->base_level(),
+          ioptions_.level_compaction_dynamic_level_bytes),
      mutable_cf_options.max_compaction_bytes, output_path_id,
      GetCompressionType(ioptions_, vstorage, mutable_cf_options, output_level,
                         vstorage->base_level()),
-      std::move(grandparents), /* is manual compaction */ true);
+      /* max_subcompactions */ 0, std::move(grandparents),
+      /* is manual compaction */ true);

  TEST_SYNC_POINT_CALLBACK("CompactionPicker::CompactRange:Return", compaction);
  RegisterCompaction(compaction);
@@ -941,6 +949,9 @@ void CompactionPicker::UnregisterCompaction(Compaction* c) {

 bool LevelCompactionPicker::NeedsCompaction(
    const VersionStorageInfo* vstorage) const {
+  if (!vstorage->ExpiredTtlFiles().empty()) {
+    return true;
+  }
  if (!vstorage->BottommostFilesMarkedForCompaction().empty()) {
    return true;
  }
@@ -1010,6 +1021,8 @@ class LevelCompactionBuilder {
  // If there is any file marked for compaction, put put it into inputs.
  void PickFilesMarkedForCompaction();

+  void PickExpiredTtlFiles();
+
  const std::string& cf_name_;
  VersionStorageInfo* vstorage_;
  CompactionPicker* compaction_picker_;
@@ -1080,6 +1093,42 @@ void LevelCompactionBuilder::PickFilesMarkedForCompaction() {
  start_level_inputs_.files.clear();
 }

+void LevelCompactionBuilder::PickExpiredTtlFiles() {
+  if (vstorage_->ExpiredTtlFiles().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);
+    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) ||
+        (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_->ExpiredTtlFiles()) {
+    if (continuation(level_file)) {
+      // found the compaction!
+      return;
+    }
+  }
+
+  start_level_inputs_.files.clear();
+}
+
 void LevelCompactionBuilder::SetupInitialFiles() {
  // Find the compactions by size on all levels.
  bool skipped_l0_to_base = false;
@@ -1131,32 +1180,40 @@ void LevelCompactionBuilder::SetupInitialFiles() {
  // if we didn't find a compaction, check if there are any files marked for
  // compaction
  if (start_level_inputs_.empty()) {
-    is_manual_ = true;
    parent_index_ = base_index_ = -1;
+
    PickFilesMarkedForCompaction();
-    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;
-      }
-    } else {
+    if (!start_level_inputs_.empty()) {
+      is_manual_ = true;
      compaction_reason_ = CompactionReason::kFilesMarkedForCompaction;
+      return;
+    }
+
+    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;
+    }
+
+    assert(start_level_inputs_.empty());
+    PickExpiredTtlFiles();
+    if (!start_level_inputs_.empty()) {
+      compaction_reason_ = CompactionReason::kTtl;
    }
  }
 }
@@ -1258,13 +1315,16 @@ Compaction* LevelCompactionBuilder::PickCompaction() {
 Compaction* LevelCompactionBuilder::GetCompaction() {
  auto c = new Compaction(
      vstorage_, ioptions_, mutable_cf_options_, std::move(compaction_inputs_),
-      output_level_, mutable_cf_options_.MaxFileSizeForLevel(output_level_),
+      output_level_,
+      MaxFileSizeForLevel(mutable_cf_options_, output_level_,
+          ioptions_.compaction_style, vstorage_->base_level(),
+          ioptions_.level_compaction_dynamic_level_bytes),
      mutable_cf_options_.max_compaction_bytes,
      GetPathId(ioptions_, mutable_cf_options_, output_level_),
      GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
                         output_level_, vstorage_->base_level()),
-      std::move(grandparents_), is_manual_, start_level_score_,
-      false /* deletion_compaction */, compaction_reason_);
+      /* max_subcompactions */ 0, std::move(grandparents_), is_manual_,
+      start_level_score_, false /* deletion_compaction */, compaction_reason_);

  // If it's level 0 compaction, make sure we don't execute any other level 0
  // compactions in parallel
@@ -1287,10 +1347,10 @@ uint32_t LevelCompactionBuilder::GetPathId(
    const ImmutableCFOptions& ioptions,
    const MutableCFOptions& mutable_cf_options, int level) {
  uint32_t p = 0;
-  assert(!ioptions.db_paths.empty());
+  assert(!ioptions.cf_paths.empty());

  // size remaining in the most recent path
-  uint64_t current_path_size = ioptions.db_paths[0].target_size;
+  uint64_t current_path_size = ioptions.cf_paths[0].target_size;

  uint64_t level_size;
  int cur_level = 0;
@@ -1300,7 +1360,7 @@ uint32_t LevelCompactionBuilder::GetPathId(
  level_size = mutable_cf_options.max_bytes_for_level_base;

  // Last path is the fallback
-  while (p < ioptions.db_paths.size() - 1) {
+  while (p < ioptions.cf_paths.size() - 1) {
    if (level_size <= current_path_size) {
      if (cur_level == level) {
        // Does desired level fit in this path?
@@ -1327,7 +1387,7 @@ uint32_t LevelCompactionBuilder::GetPathId(
      }
    }
    p++;
-    current_path_size = ioptions.db_paths[p].target_size;
+    current_path_size = ioptions.cf_paths[p].target_size;
  }
  return p;
 }
@@ -1512,8 +1572,9 @@ Compaction* FIFOCompactionPicker::PickTTLCompaction(

  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs), 0, 0, 0, 0,
-      kNoCompression, {}, /* is manual */ false, vstorage->CompactionScore(0),
-      /* is deletion compaction */ true, CompactionReason::kFIFOTtl);
+      kNoCompression, /* max_subcompactions */ 0, {}, /* is manual */ false,
+      vstorage->CompactionScore(0), /* is deletion compaction */ true,
+      CompactionReason::kFIFOTtl);
  return c;
 }

@@ -1531,18 +1592,28 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(
    if (mutable_cf_options.compaction_options_fifo.allow_compaction &&
        level_files.size() > 0) {
      CompactionInputFiles comp_inputs;
+      // try to prevent same files from being compacted multiple times, which
+      // could produce large files that may never TTL-expire. Achieve this by
+      // disallowing compactions with files larger than memtable (inflate its
+      // size by 10% to account for uncompressed L0 files that may have size
+      // slightly greater than memtable size limit).
+      size_t max_compact_bytes_per_del_file =
+          static_cast<size_t>(MultiplyCheckOverflow(
+              static_cast<uint64_t>(mutable_cf_options.write_buffer_size),
+              1.1));
      if (FindIntraL0Compaction(
              level_files,
              mutable_cf_options
-                  .level0_file_num_compaction_trigger /* min_files_to_compact */,
-              mutable_cf_options.write_buffer_size, &comp_inputs)) {
+                  .level0_file_num_compaction_trigger /* min_files_to_compact */
+              ,
+              max_compact_bytes_per_del_file, &comp_inputs)) {
        Compaction* c = new Compaction(
            vstorage, ioptions_, mutable_cf_options, {comp_inputs}, 0,
            16 * 1024 * 1024 /* output file size limit */,
            0 /* max compaction bytes, not applicable */,
-            0 /* output path ID */, mutable_cf_options.compression, {},
-            /* is manual */ false, vstorage->CompactionScore(0),
-            /* is deletion compaction */ false,
+            0 /* output path ID */, mutable_cf_options.compression,
+            0 /* max_subcompactions */, {}, /* is manual */ false,
+            vstorage->CompactionScore(0), /* is deletion compaction */ false,
            CompactionReason::kFIFOReduceNumFiles);
        return c;
      }
@@ -1588,8 +1659,9 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(

  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs), 0, 0, 0, 0,
-      kNoCompression, {}, /* is manual */ false, vstorage->CompactionScore(0),
-      /* is deletion compaction */ true, CompactionReason::kFIFOMaxSize);
+      kNoCompression, /* max_subcompactions */ 0, {}, /* is manual */ false,
+      vstorage->CompactionScore(0), /* is deletion compaction */ true,
+      CompactionReason::kFIFOMaxSize);
  return c;
 }

@@ -1612,9 +1684,13 @@ Compaction* FIFOCompactionPicker::PickCompaction(
 Compaction* FIFOCompactionPicker::CompactRange(
    const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
    VersionStorageInfo* vstorage, int input_level, int output_level,
-    uint32_t /*output_path_id*/, const InternalKey* /*begin*/,
-    const InternalKey* /*end*/, InternalKey** compaction_end,
-    bool* /*manual_conflict*/) {
+    uint32_t /*output_path_id*/, uint32_t /*max_subcompactions*/,
+    const InternalKey* /*begin*/, const InternalKey* /*end*/,
+    InternalKey** compaction_end, bool* /*manual_conflict*/) {
+#ifdef NDEBUG
+  (void)input_level;
+  (void)output_level;
+#endif
  assert(input_level == 0);
  assert(output_level == 0);
  *compaction_end = nullptr;
@@ -58,7 +58,8 @@ class CompactionPicker {
  virtual Compaction* CompactRange(
      const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
      VersionStorageInfo* vstorage, int input_level, int output_level,
-      uint32_t output_path_id, const InternalKey* begin, const InternalKey* end,
+      uint32_t output_path_id, uint32_t max_subcompactions,
+      const InternalKey* begin, const InternalKey* end,
      InternalKey** compaction_end, bool* manual_conflict);

  // The maximum allowed output level.  Default value is NumberLevels() - 1.
@@ -238,7 +239,8 @@ class FIFOCompactionPicker : public CompactionPicker {
  virtual Compaction* CompactRange(
      const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
      VersionStorageInfo* vstorage, int input_level, int output_level,
-      uint32_t output_path_id, const InternalKey* begin, const InternalKey* end,
+      uint32_t output_path_id, uint32_t max_subcompactions,
+      const InternalKey* begin, const InternalKey* end,
      InternalKey** compaction_end, bool* manual_conflict) override;

  // The maximum allowed output level.  Always returns 0.
@@ -280,6 +282,7 @@ class NullCompactionPicker : public CompactionPicker {
                           VersionStorageInfo* /*vstorage*/,
                           int /*input_level*/, int /*output_level*/,
                           uint32_t /*output_path_id*/,
+                           uint32_t /*max_subcompactions*/,
                           const InternalKey* /*begin*/,
                           const InternalKey* /*end*/,
                           InternalKey** /*compaction_end*/,
@@ -59,7 +59,7 @@ class CompactionPickerTest : public testing::Test {
        vstorage_(nullptr) {
    fifo_options_.max_table_files_size = 1;
    mutable_cf_options_.RefreshDerivedOptions(ioptions_);
-    ioptions_.db_paths.emplace_back("dummy",
+    ioptions_.cf_paths.emplace_back("dummy",
                                    std::numeric_limits<uint64_t>::max());
  }

@@ -406,9 +406,9 @@ uint32_t UniversalCompactionPicker::GetPathId(
      file_size *
      (100 - mutable_cf_options.compaction_options_universal.size_ratio) / 100;
  uint32_t p = 0;
-  assert(!ioptions.db_paths.empty());
-  for (; p < ioptions.db_paths.size() - 1; p++) {
-    uint64_t target_size = ioptions.db_paths[p].target_size;
+  assert(!ioptions.cf_paths.empty());
+  for (; p < ioptions.cf_paths.size() - 1; p++) {
+    uint64_t target_size = ioptions.cf_paths[p].target_size;
    if (target_size > file_size &&
        accumulated_size + (target_size - file_size) > future_size) {
      return p;
@@ -609,11 +609,13 @@ Compaction* UniversalCompactionPicker::PickCompactionToReduceSortedRuns(
  }
  return new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs), output_level,
-      mutable_cf_options.MaxFileSizeForLevel(output_level), LLONG_MAX, path_id,
+      MaxFileSizeForLevel(mutable_cf_options, output_level,
+                          kCompactionStyleUniversal),
+      LLONG_MAX, path_id,
      GetCompressionType(ioptions_, vstorage, mutable_cf_options, start_level,
                         1, enable_compression),
-      /* grandparents */ {}, /* is manual */ false, score,
-      false /* deletion_compaction */, compaction_reason);
+      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
+      score, false /* deletion_compaction */, compaction_reason);
 }

 // Look at overall size amplification. If size amplification
@@ -742,12 +744,13 @@ Compaction* UniversalCompactionPicker::PickCompactionToReduceSizeAmp(

  return new Compaction(
      vstorage, ioptions_, mutable_cf_options, std::move(inputs),
-      output_level, mutable_cf_options.MaxFileSizeForLevel(output_level),
+      output_level, MaxFileSizeForLevel(mutable_cf_options, output_level,
+          kCompactionStyleUniversal),
      /* max_grandparent_overlap_bytes */ LLONG_MAX, path_id,
      GetCompressionType(ioptions_, vstorage, mutable_cf_options,
                         output_level, 1),
-      /* grandparents */ {}, /* is manual */ false, score,
-      false /* deletion_compaction */,
+      /* max_subcompactions */ 0, /* grandparents */ {}, /* is manual */ false,
+      score, false /* deletion_compaction */,
      CompactionReason::kUniversalSizeAmplification);
 }
 }  // namespace rocksdb
@@ -2,6 +2,7 @@
 //  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 <array>
 #include <map>
 #include <string>

@@ -433,6 +434,145 @@ TEST_F(ComparatorDBTest, TwoStrComparator) {
  }
 }

+TEST_F(ComparatorDBTest, FindShortestSeparator) {
+  std::string s1 = "abc1xyz";
+  std::string s2 = "abc3xy";
+
+  BytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_EQ("abc2", s1);
+
+  s1 = "abc5xyztt";
+
+  ReverseBytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_EQ("abc5", s1);
+
+  s1 = "abc3";
+  s2 = "abc2xy";
+  ReverseBytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_EQ("abc3", s1);
+
+  s1 = "abc3xyz";
+  s2 = "abc2xy";
+  ReverseBytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_EQ("abc3", s1);
+
+  s1 = "abc3xyz";
+  s2 = "abc2";
+  ReverseBytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_EQ("abc3", s1);
+
+  std::string old_s1 = s1 = "abc2xy";
+  s2 = "abc2";
+  ReverseBytewiseComparator()->FindShortestSeparator(&s1, s2);
+  ASSERT_TRUE(old_s1 >= s1);
+  ASSERT_TRUE(s1 > s2);
+}
+
+TEST_F(ComparatorDBTest, SeparatorSuccessorRandomizeTest) {
+  // Char list for boundary cases.
+  std::array<unsigned char, 6> char_list{{0, 1, 2, 253, 254, 255}};
+  Random rnd(301);
+
+  for (int attempts = 0; attempts < 1000; attempts++) {
+    uint32_t size1 = rnd.Skewed(4);
+    uint32_t size2;
+
+    if (rnd.OneIn(2)) {
+      // size2 to be random size
+      size2 = rnd.Skewed(4);
+    } else {
+      // size1 is within [-2, +2] of size1
+      int diff = static_cast<int>(rnd.Uniform(5)) - 2;
+      int tmp_size2 = static_cast<int>(size1) + diff;
+      if (tmp_size2 < 0) {
+        tmp_size2 = 0;
+      }
+      size2 = static_cast<uint32_t>(tmp_size2);
+    }
+
+    std::string s1;
+    std::string s2;
+    for (uint32_t i = 0; i < size1; i++) {
+      if (rnd.OneIn(2)) {
+        // Use random byte
+        s1 += static_cast<char>(rnd.Uniform(256));
+      } else {
+        // Use one byte in char_list
+        char c = static_cast<char>(char_list[rnd.Uniform(sizeof(char_list))]);
+        s1 += c;
+      }
+    }
+
+    // First set s2 to be the same as s1, and then modify s2.
+    s2 = s1;
+    s2.resize(size2);
+    // We start from the back of the string
+    if (size2 > 0) {
+      uint32_t pos = size2 - 1;
+      do {
+        if (pos >= size1 || rnd.OneIn(4)) {
+          // For 1/4 chance, use random byte
+          s2[pos] = static_cast<char>(rnd.Uniform(256));
+        } else if (rnd.OneIn(4)) {
+          // In 1/4 chance, stop here.
+          break;
+        } else {
+          // Create a char within [-2, +2] of the matching char of s1.
+          int diff = static_cast<int>(rnd.Uniform(5)) - 2;
+          // char may be signed or unsigned based on platform.
+          int s1_char = static_cast<int>(static_cast<unsigned char>(s1[pos]));
+          int s2_char = s1_char + diff;
+          if (s2_char < 0) {
+            s2_char = 0;
+          }
+          if (s2_char > 255) {
+            s2_char = 255;
+          }
+          s2[pos] = static_cast<char>(s2_char);
+        }
+      } while (pos-- != 0);
+    }
+
+    // Test separators
+    for (int rev = 0; rev < 2; rev++) {
+      if (rev == 1) {
+        // switch s1 and s2
+        std::string t = s1;
+        s1 = s2;
+        s2 = t;
+      }
+      std::string separator = s1;
+      BytewiseComparator()->FindShortestSeparator(&separator, s2);
+      std::string rev_separator = s1;
+      ReverseBytewiseComparator()->FindShortestSeparator(&rev_separator, s2);
+
+      if (s1 == s2) {
+        ASSERT_EQ(s1, separator);
+        ASSERT_EQ(s2, rev_separator);
+      } else if (s1 < s2) {
+        ASSERT_TRUE(s1 <= separator);
+        ASSERT_TRUE(s2 > separator);
+        ASSERT_LE(separator.size(), std::max(s1.size(), s2.size()));
+        ASSERT_EQ(s1, rev_separator);
+      } else {
+        ASSERT_TRUE(s1 >= rev_separator);
+        ASSERT_TRUE(s2 < rev_separator);
+        ASSERT_LE(rev_separator.size(), std::max(s1.size(), s2.size()));
+        ASSERT_EQ(s1, separator);
+      }
+    }
+
+    // Test successors
+    std::string succ = s1;
+    BytewiseComparator()->FindShortSuccessor(&succ);
+    ASSERT_TRUE(succ >= s1);
+
+    succ = s1;
+    ReverseBytewiseComparator()->FindShortSuccessor(&succ);
+    ASSERT_TRUE(succ <= s1);
+  }
+}
+
 }  // namespace rocksdb

 int main(int argc, char** argv) {
@@ -50,8 +50,9 @@ Status VerifySstFileChecksum(const Options& options,
  std::unique_ptr<RandomAccessFileReader> file_reader(
      new RandomAccessFileReader(std::move(file), file_path));
  s = ioptions.table_factory->NewTableReader(
-      TableReaderOptions(ioptions, env_options, internal_comparator,
-                         false /* skip_filters */, -1 /* level */),
+      TableReaderOptions(ioptions, options.prefix_extractor.get(), env_options,
+                         internal_comparator, false /* skip_filters */,
+                         -1 /* level */),
      std::move(file_reader), file_size, &table_reader,
      false /* prefetch_index_and_filter_in_cache */);
  if (!s.ok()) {
@@ -333,9 +333,9 @@ TEST_F(CorruptionTest, TableFileIndexData) {
  Corrupt(kTableFile, -2000, 500);
  Reopen();
  dbi = reinterpret_cast<DBImpl*>(db_);
-  // one full file should be readable, since only one was corrupted
+  // one full file may be readable, since only one was corrupted
  // the other file should be fully non-readable, since index was corrupted
-  Check(5000, 5000);
+  Check(0, 5000);
  ASSERT_NOK(dbi->VerifyChecksum());
 }

@@ -305,6 +305,41 @@ TEST_F(DBBlockCacheTest, IndexAndFilterBlocksOfNewTableAddedToCache) {
            TestGetTickerCount(options, BLOCK_CACHE_INDEX_HIT));
 }

+// With fill_cache = false, fills up the cache, then iterates over the entire
+// db, verify dummy entries inserted in `BlockBasedTable::NewDataBlockIterator`
+// does not cause heap-use-after-free errors in COMPILE_WITH_ASAN=1 runs
+TEST_F(DBBlockCacheTest, FillCacheAndIterateDB) {
+  ReadOptions read_options;
+  read_options.fill_cache = false;
+  auto table_options = GetTableOptions();
+  auto options = GetOptions(table_options);
+  InitTable(options);
+
+  std::shared_ptr<Cache> cache = NewLRUCache(10, 0, true);
+  table_options.block_cache = cache;
+  options.table_factory.reset(new BlockBasedTableFactory(table_options));
+  Reopen(options);
+  ASSERT_OK(Put("key1", "val1"));
+  ASSERT_OK(Put("key2", "val2"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("key3", "val3"));
+  ASSERT_OK(Put("key4", "val4"));
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("key5", "val5"));
+  ASSERT_OK(Put("key6", "val6"));
+  ASSERT_OK(Flush());
+
+  Iterator* iter = nullptr;
+
+  iter = db_->NewIterator(read_options);
+  iter->Seek(ToString(0));
+  while (iter->Valid()) {
+    iter->Next();
+  }
+  delete iter;
+  iter = nullptr;
+}
+
 TEST_F(DBBlockCacheTest, IndexAndFilterBlocksStats) {
  Options options = CurrentOptions();
  options.create_if_missing = true;
@@ -1057,10 +1057,10 @@ TEST_F(DBBloomFilterTest, OptimizeFiltersForHits) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  CompactRangeOptions compact_options;
@@ -74,6 +74,48 @@ class FlushedFileCollector : public EventListener {
  std::mutex mutex_;
 };

+class CompactionStatsCollector : public EventListener {
+public:
+  CompactionStatsCollector()
+      : compaction_completed_(static_cast<int>(CompactionReason::kNumOfReasons)) {
+    for (auto& v : compaction_completed_) {
+      v.store(0);
+    }
+  }
+
+  ~CompactionStatsCollector() {}
+
+  virtual void OnCompactionCompleted(DB* /* db */,
+      const CompactionJobInfo& info) override {
+    int k = static_cast<int>(info.compaction_reason);
+    int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+    assert(k >= 0 && k < num_of_reasons);
+    compaction_completed_[k]++;
+  }
+
+  virtual void OnExternalFileIngested(DB* /* db */,
+      const ExternalFileIngestionInfo& /* info */) override {
+    int k = static_cast<int>(CompactionReason::kExternalSstIngestion);
+    compaction_completed_[k]++;
+  }
+
+  virtual void OnFlushCompleted(DB* /* db */,
+      const FlushJobInfo& /* info */) override {
+    int k = static_cast<int>(CompactionReason::kFlush);
+    compaction_completed_[k]++;
+  }
+
+  int NumberOfCompactions(CompactionReason reason) const {
+    int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+    int k = static_cast<int>(reason);
+    assert(k >= 0 && k < num_of_reasons);
+    return compaction_completed_.at(k).load();
+  }
+
+private:
+  std::vector<std::atomic<int>> compaction_completed_;
+};
+
 static const int kCDTValueSize = 1000;
 static const int kCDTKeysPerBuffer = 4;
 static const int kCDTNumLevels = 8;
@@ -154,6 +196,40 @@ void VerifyCompactionResult(
 #endif
 }

+/*
+ * Verifies compaction stats of cfd are valid.
+ *
+ * For each level of cfd, its compaction stats are valid if
+ * 1) sum(stat.counts) == stat.count, and
+ * 2) stat.counts[i] == collector.NumberOfCompactions(i)
+ */
+void VerifyCompactionStats(ColumnFamilyData& cfd,
+    const CompactionStatsCollector& collector) {
+#ifndef NDEBUG
+  InternalStats* internal_stats_ptr = cfd.internal_stats();
+  ASSERT_TRUE(internal_stats_ptr != nullptr);
+  const std::vector<InternalStats::CompactionStats>& comp_stats =
+      internal_stats_ptr->TEST_GetCompactionStats();
+  const int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+  std::vector<int> counts(num_of_reasons, 0);
+  // Count the number of compactions caused by each CompactionReason across
+  // all levels.
+  for (const auto& stat : comp_stats) {
+    int sum = 0;
+    for (int i = 0; i < num_of_reasons; i++) {
+      counts[i] += stat.counts[i];
+      sum += stat.counts[i];
+    }
+    ASSERT_EQ(sum, stat.count);
+  }
+  // Verify InternalStats bookkeeping matches that of CompactionStatsCollector,
+  // assuming that all compactions complete.
+  for (int i = 0; i < num_of_reasons; i++) {
+    ASSERT_EQ(collector.NumberOfCompactions(static_cast<CompactionReason>(i)), counts[i]);
+  }
+#endif /* NDEBUG */
+}
+
 const SstFileMetaData* PickFileRandomly(
    const ColumnFamilyMetaData& cf_meta,
    Random* rand,
@@ -360,7 +436,7 @@ TEST_F(DBCompactionTest, TestTableReaderForCompaction) {
      });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "TableCache::GetTableReader:0",
-      [&](void* arg) { num_new_table_reader++; });
+      [&](void* /*arg*/) { num_new_table_reader++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  for (int k = 0; k < options.level0_file_num_compaction_trigger; ++k) {
@@ -916,7 +992,7 @@ TEST_P(DBCompactionTestWithParam, TrivialMoveOneFile) {
  int32_t trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -973,10 +1049,10 @@ TEST_P(DBCompactionTestWithParam, TrivialMoveNonOverlappingFiles) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -1072,10 +1148,10 @@ TEST_P(DBCompactionTestWithParam, TrivialMoveTargetLevel) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -1131,10 +1207,10 @@ TEST_P(DBCompactionTestWithParam, ManualCompactionPartial) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  bool first = true;
  // Purpose of dependencies:
  // 4 -> 1: ensure the order of two non-trivial compactions
@@ -1145,7 +1221,7 @@ TEST_P(DBCompactionTestWithParam, ManualCompactionPartial) {
       {"DBCompaction::ManualPartial:5", "DBCompaction::ManualPartial:2"},
       {"DBCompaction::ManualPartial:5", "DBCompaction::ManualPartial:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (first) {
          first = false;
          TEST_SYNC_POINT("DBCompaction::ManualPartial:4");
@@ -1276,17 +1352,17 @@ TEST_F(DBCompactionTest, DISABLED_ManualPartialFill) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  bool first = true;
  bool second = true;
  rocksdb::SyncPoint::GetInstance()->LoadDependency(
      {{"DBCompaction::PartialFill:4", "DBCompaction::PartialFill:1"},
       {"DBCompaction::PartialFill:2", "DBCompaction::PartialFill:3"}});
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun", [&](void* /*arg*/) {
        if (first) {
          TEST_SYNC_POINT("DBCompaction::PartialFill:4");
          first = false;
@@ -1692,10 +1768,10 @@ TEST_P(DBCompactionTestWithParam, TrivialMoveToLastLevelWithFiles) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -1983,6 +2059,125 @@ TEST_P(DBCompactionTestWithParam, LevelCompactionPathUse) {
  Destroy(options);
 }

+TEST_P(DBCompactionTestWithParam, LevelCompactionCFPathUse) {
+  Options options = CurrentOptions();
+  options.db_paths.emplace_back(dbname_, 500 * 1024);
+  options.db_paths.emplace_back(dbname_ + "_2", 4 * 1024 * 1024);
+  options.db_paths.emplace_back(dbname_ + "_3", 1024 * 1024 * 1024);
+  options.memtable_factory.reset(
+    new SpecialSkipListFactory(KNumKeysByGenerateNewFile - 1));
+  options.compaction_style = kCompactionStyleLevel;
+  options.write_buffer_size = 110 << 10;  // 110KB
+  options.arena_block_size = 4 << 10;
+  options.level0_file_num_compaction_trigger = 2;
+  options.num_levels = 4;
+  options.max_bytes_for_level_base = 400 * 1024;
+  options.max_subcompactions = max_subcompactions_;
+
+  std::vector<Options> option_vector;
+  option_vector.emplace_back(options);
+  ColumnFamilyOptions cf_opt1(options), cf_opt2(options);
+  // Configure CF1 specific paths.
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1", 500 * 1024);
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1_2", 4 * 1024 * 1024);
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1_3", 1024 * 1024 * 1024);
+  option_vector.emplace_back(DBOptions(options), cf_opt1);
+  CreateColumnFamilies({"one"},option_vector[1]);
+
+  // Configura CF2 specific paths.
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2", 500 * 1024);
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2_2", 4 * 1024 * 1024);
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2_3", 1024 * 1024 * 1024);
+  option_vector.emplace_back(DBOptions(options), cf_opt2);
+  CreateColumnFamilies({"two"},option_vector[2]);
+
+  ReopenWithColumnFamilies({"default", "one", "two"}, option_vector);
+
+  Random rnd(301);
+  int key_idx = 0;
+  int key_idx1 = 0;
+  int key_idx2 = 0;
+
+  auto generate_file = [&]() {
+    GenerateNewFile(0, &rnd, &key_idx);
+    GenerateNewFile(1, &rnd, &key_idx1);
+    GenerateNewFile(2, &rnd, &key_idx2);
+  };
+
+  auto check_sstfilecount = [&](int path_id, int expected) {
+    ASSERT_EQ(expected, GetSstFileCount(options.db_paths[path_id].path));
+    ASSERT_EQ(expected, GetSstFileCount(cf_opt1.cf_paths[path_id].path));
+    ASSERT_EQ(expected, GetSstFileCount(cf_opt2.cf_paths[path_id].path));
+  };
+
+  auto check_filesperlevel = [&](const std::string& expected) {
+    ASSERT_EQ(expected, FilesPerLevel(0));
+    ASSERT_EQ(expected, FilesPerLevel(1));
+    ASSERT_EQ(expected, FilesPerLevel(2));
+  };
+
+  auto check_getvalues = [&]() {
+    for (int i = 0; i < key_idx; i++) {
+      auto v = Get(0, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+
+    for (int i = 0; i < key_idx1; i++) {
+      auto v = Get(1, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+
+    for (int i = 0; i < key_idx2; i++) {
+      auto v = Get(2, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+  };
+
+  // Check that default column family uses db_paths.
+  // And Column family "one" uses cf_paths.
+
+  // First three 110KB files are not going to second path.
+  // After that, (100K, 200K)
+  for (int num = 0; num < 3; num++) {
+    generate_file();
+  }
+
+  // Another 110KB triggers a compaction to 400K file to fill up first path
+  generate_file();
+  check_sstfilecount(1, 3);
+
+  // (1, 4)
+  generate_file();
+  check_filesperlevel("1,4");
+  check_sstfilecount(1, 4);
+  check_sstfilecount(0, 1);
+
+  // (1, 4, 1)
+  generate_file();
+  check_filesperlevel("1,4,1");
+  check_sstfilecount(2, 1);
+  check_sstfilecount(1, 4);
+  check_sstfilecount(0, 1);
+
+  // (1, 4, 2)
+  generate_file();
+  check_filesperlevel("1,4,2");
+  check_sstfilecount(2, 2);
+  check_sstfilecount(1, 4);
+  check_sstfilecount(0, 1);
+
+  check_getvalues();
+
+  ReopenWithColumnFamilies({"default", "one", "two"}, option_vector);
+
+  check_getvalues();
+
+  Destroy(options, true);
+}
+
 TEST_P(DBCompactionTestWithParam, ConvertCompactionStyle) {
  Random rnd(301);
  int max_key_level_insert = 200;
@@ -2573,16 +2768,16 @@ TEST_P(DBCompactionTestWithParam, CompressLevelCompaction) {

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "Compaction::InputCompressionMatchesOutput:Matches",
-      [&](void* arg) { matches++; });
+      [&](void* /*arg*/) { matches++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "Compaction::InputCompressionMatchesOutput:DidntMatch",
-      [&](void* arg) { didnt_match++; });
+      [&](void* /*arg*/) { didnt_match++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial++; });
+      [&](void* /*arg*/) { non_trivial++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Reopen(options);
@@ -2744,10 +2939,10 @@ TEST_P(DBCompactionTestWithParam, ForceBottommostLevelCompaction) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial_move++; });
+      [&](void* /*arg*/) { non_trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -2933,6 +3128,48 @@ TEST_P(DBCompactionTestWithParam, IntraL0CompactionDoesNotObsoleteDeletions) {
  ASSERT_TRUE(db_->Get(roptions, Key(0), &result).IsNotFound());
 }

+TEST_P(DBCompactionTestWithParam, FullCompactionInBottomPriThreadPool) {
+  const int kNumFilesTrigger = 3;
+  Env::Default()->SetBackgroundThreads(1, Env::Priority::BOTTOM);
+  for (bool use_universal_compaction : {false, true}) {
+    Options options = CurrentOptions();
+    if (use_universal_compaction) {
+      options.compaction_style = kCompactionStyleUniversal;
+    } else {
+      options.compaction_style = kCompactionStyleLevel;
+      options.level_compaction_dynamic_level_bytes = true;
+    }
+    options.num_levels = 4;
+    options.write_buffer_size = 100 << 10;     // 100KB
+    options.target_file_size_base = 32 << 10;  // 32KB
+    options.level0_file_num_compaction_trigger = kNumFilesTrigger;
+    // Trigger compaction if size amplification exceeds 110%
+    options.compaction_options_universal.max_size_amplification_percent = 110;
+    DestroyAndReopen(options);
+
+    int num_bottom_pri_compactions = 0;
+    SyncPoint::GetInstance()->SetCallBack(
+        "DBImpl::BGWorkBottomCompaction",
+        [&](void* /*arg*/) { ++num_bottom_pri_compactions; });
+    SyncPoint::GetInstance()->EnableProcessing();
+
+    Random rnd(301);
+    for (int num = 0; num < kNumFilesTrigger; num++) {
+      ASSERT_EQ(NumSortedRuns(), num);
+      int key_idx = 0;
+      GenerateNewFile(&rnd, &key_idx);
+    }
+    dbfull()->TEST_WaitForCompact();
+
+    ASSERT_EQ(1, num_bottom_pri_compactions);
+
+    // Verify that size amplification did occur
+    ASSERT_EQ(NumSortedRuns(), 1);
+    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
+  }
+  Env::Default()->SetBackgroundThreads(0, Env::Priority::BOTTOM);
+}
+
 TEST_F(DBCompactionTest, OptimizedDeletionObsoleting) {
  // Deletions can be dropped when compacted to non-last level if they fall
  // outside the lower-level files' key-ranges.
@@ -3091,6 +3328,13 @@ TEST_F(DBCompactionTest, CompactBottomLevelFilesWithDeletions) {
  // compactions should be triggered, which reduce the size of each bottom-level
  // file without changing file count.
  db_->ReleaseSnapshot(snapshot);
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "LevelCompactionPicker::PickCompaction:Return", [&](void* arg) {
+        Compaction* compaction = reinterpret_cast<Compaction*>(arg);
+        ASSERT_TRUE(compaction->compaction_reason() ==
+                    CompactionReason::kBottommostFiles);
+      });
+  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
  dbfull()->TEST_WaitForCompact();
  db_->GetLiveFilesMetaData(&post_release_metadata);
  ASSERT_EQ(pre_release_metadata.size(), post_release_metadata.size());
@@ -3104,6 +3348,66 @@ TEST_F(DBCompactionTest, CompactBottomLevelFilesWithDeletions) {
    // deletion markers/deleted keys.
    ASSERT_LT(post_file.size, pre_file.size);
  }
+  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
+}
+
+TEST_F(DBCompactionTest, LevelCompactExpiredTtlFiles) {
+  const int kNumKeysPerFile = 32;
+  const int kNumLevelFiles = 2;
+  const int kValueSize = 1024;
+
+  Options options = CurrentOptions();
+  options.compression = kNoCompression;
+  options.ttl = 24 * 60 * 60;  // 24 hours
+  options.max_open_files = -1;
+  env_->time_elapse_only_sleep_ = false;
+  options.env = env_;
+
+  env_->addon_time_.store(0);
+  DestroyAndReopen(options);
+
+  Random rnd(301);
+  for (int i = 0; i < kNumLevelFiles; ++i) {
+    for (int j = 0; j < kNumKeysPerFile; ++j) {
+      ASSERT_OK(
+          Put(Key(i * kNumKeysPerFile + j), RandomString(&rnd, kValueSize)));
+    }
+    Flush();
+  }
+  Flush();
+  dbfull()->TEST_WaitForCompact();
+  MoveFilesToLevel(3);
+  ASSERT_EQ("0,0,0,2", FilesPerLevel());
+
+  for (int i = 0; i < kNumLevelFiles; ++i) {
+    for (int j = 0; j < kNumKeysPerFile; ++j) {
+      // Overwrite previous keys with smaller, but predictable, values.
+      ASSERT_OK(Delete(Key(i * kNumKeysPerFile + j)));
+    }
+    Flush();
+  }
+  dbfull()->TEST_WaitForCompact();
+  ASSERT_EQ("2,0,0,2", FilesPerLevel());
+  MoveFilesToLevel(1);
+  ASSERT_EQ("0,2,0,2", FilesPerLevel());
+
+  env_->addon_time_.fetch_add(36 * 60 * 60);  // 36 hours
+  ASSERT_EQ("0,2,0,2", FilesPerLevel());
+
+  // Just do a siimple write + flush so that the Ttl expired files get
+  // compacted.
+  ASSERT_OK(Put("a", "1"));
+  Flush();
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "LevelCompactionPicker::PickCompaction:Return", [&](void* arg) {
+        Compaction* compaction = reinterpret_cast<Compaction*>(arg);
+        ASSERT_TRUE(compaction->compaction_reason() == CompactionReason::kTtl);
+      });
+  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
+  dbfull()->TEST_WaitForCompact();
+  // All non-L0 files are deleted, as they contained only deleted data.
+  ASSERT_EQ("1", FilesPerLevel());
+  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
 }

 TEST_F(DBCompactionTest, CompactRangeDelayedByL0FileCount) {
@@ -3376,6 +3680,28 @@ TEST_F(DBCompactionTest, CompactRangeFlushOverlappingMemtable) {
  }
 }

+TEST_F(DBCompactionTest, CompactionStatsTest) {
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = 2;
+  CompactionStatsCollector* collector = new CompactionStatsCollector();
+  options.listeners.emplace_back(collector);
+  DestroyAndReopen(options);
+
+  for (int i = 0; i < 32; i++) {
+    for (int j = 0; j < 5000; j++) {
+      Put(std::to_string(j), std::string(1, 'A'));
+    }
+    ASSERT_OK(Flush());
+    ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable());
+  }
+  dbfull()->TEST_WaitForCompact();
+  ColumnFamilyHandleImpl* cfh =
+      static_cast<ColumnFamilyHandleImpl*>(dbfull()->DefaultColumnFamily());
+  ColumnFamilyData* cfd = cfh->cfd();
+
+  VerifyCompactionStats(*cfd, *collector);
+}
+
 INSTANTIATE_TEST_CASE_P(DBCompactionTestWithParam, DBCompactionTestWithParam,
                        ::testing::Values(std::make_tuple(1, true),
                                          std::make_tuple(1, false),
@@ -3395,7 +3721,7 @@ TEST_P(DBCompactionDirectIOTest, DirectIO) {
      "TableCache::NewIterator:for_compaction", [&](void* arg) {
        bool* use_direct_reads = static_cast<bool*>(arg);
        ASSERT_EQ(*use_direct_reads,
-                  options.use_direct_io_for_flush_and_compaction);
+                  options.use_direct_reads);
      });
  SyncPoint::GetInstance()->SetCallBack(
      "CompactionJob::OpenCompactionOutputFile", [&](void* arg) {
@@ -3405,7 +3731,7 @@ TEST_P(DBCompactionDirectIOTest, DirectIO) {
      });
  if (options.use_direct_io_for_flush_and_compaction) {
    SyncPoint::GetInstance()->SetCallBack(
-        "SanitizeOptions:direct_io", [&](void* arg) {
+        "SanitizeOptions:direct_io", [&](void* /*arg*/) {
          readahead = true;
        });
  }
@@ -3414,7 +3740,7 @@ TEST_P(DBCompactionDirectIOTest, DirectIO) {
  MakeTables(3, "p", "q", 1);
  ASSERT_EQ("1,1,1", FilesPerLevel(1));
  Compact(1, "p1", "p9");
-  ASSERT_FALSE(readahead ^ options.use_direct_io_for_flush_and_compaction);
+  ASSERT_EQ(readahead, options.use_direct_reads);
  ASSERT_EQ("0,0,1", FilesPerLevel(1));
  Destroy(options);
  delete options.env;
@@ -194,7 +194,7 @@ TEST_F(DBTestDynamicLevel, DynamicLevelMaxBytesBase2) {
  // Hold compaction jobs to make sure
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "CompactionJob::Run():Start",
-      [&](void* arg) { env_->SleepForMicroseconds(100000); });
+      [&](void* /*arg*/) { env_->SleepForMicroseconds(100000); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
  ASSERT_OK(dbfull()->SetOptions({
      {"disable_auto_compactions", "true"},
@@ -378,7 +378,7 @@ TEST_F(DBTestDynamicLevel, DynamicLevelMaxBytesBaseInc) {
  int non_trivial = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial",
-      [&](void* arg) { non_trivial++; });
+      [&](void* /*arg*/) { non_trivial++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Random rnd(301);
@@ -74,7 +74,7 @@ Status DBImpl::EnableFileDeletions(bool force) {
 }

 int DBImpl::IsFileDeletionsEnabled() const {
-  return disable_delete_obsolete_files_;
+  return !disable_delete_obsolete_files_;
 }

 Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
@@ -72,19 +72,23 @@ TEST_F(DBFlushTest, SyncFail) {
  auto* cfd =
      reinterpret_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())
          ->cfd();
-  int refs_before = cfd->current()->TEST_refs();
  FlushOptions flush_options;
  flush_options.wait = false;
  ASSERT_OK(dbfull()->Flush(flush_options));
+  // Flush installs a new super-version. Get the ref count after that.
+  auto current_before = cfd->current();
+  int refs_before = cfd->current()->TEST_refs();
  fault_injection_env->SetFilesystemActive(false);
  TEST_SYNC_POINT("DBFlushTest::SyncFail:1");
  TEST_SYNC_POINT("DBFlushTest::SyncFail:2");
  fault_injection_env->SetFilesystemActive(true);
+  // Now the background job will do the flush; wait for it.
  dbfull()->TEST_WaitForFlushMemTable();
 #ifndef ROCKSDB_LITE
  ASSERT_EQ("", FilesPerLevel());  // flush failed.
 #endif                             // ROCKSDB_LITE
-  // Flush job should release ref count to current version.
+  // Backgroun flush job should release ref count to current version.
+  ASSERT_EQ(current_before, cfd->current());
  ASSERT_EQ(refs_before, cfd->current()->TEST_refs());
  Destroy(options);
 }
@@ -101,7 +105,7 @@ TEST_F(DBFlushTest, FlushInLowPriThreadPool) {
  std::thread::id tid;
  int num_flushes = 0, num_compactions = 0;
  SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BGWorkFlush", [&](void* arg) {
+      "DBImpl::BGWorkFlush", [&](void* /*arg*/) {
        if (tid == std::thread::id()) {
          tid = std::this_thread::get_id();
        } else {
@@ -110,7 +114,7 @@ TEST_F(DBFlushTest, FlushInLowPriThreadPool) {
        ++num_flushes;
      });
  SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BGWorkCompaction", [&](void* arg) {
+      "DBImpl::BGWorkCompaction", [&](void* /*arg*/) {
        ASSERT_EQ(tid, std::this_thread::get_id());
        ++num_compactions;
      });
@@ -97,7 +97,7 @@

 namespace rocksdb {
 const std::string kDefaultColumnFamilyName("default");
-void DumpRocksDBBuildVersion(Logger * log);
+void DumpRocksDBBuildVersion(Logger* log);

 CompressionType GetCompressionFlush(
    const ImmutableCFOptions& ioptions,
@@ -135,7 +135,7 @@ void DumpSupportInfo(Logger* logger) {
 }

 int64_t kDefaultLowPriThrottledRate = 2 * 1024 * 1024;
-} // namespace
+}  // namespace

 DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
               const bool seq_per_batch)
@@ -183,7 +183,7 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
      last_stats_dump_time_microsec_(0),
      next_job_id_(1),
      has_unpersisted_data_(false),
-      unable_to_flush_oldest_log_(false),
+      unable_to_release_oldest_log_(false),
      env_options_(BuildDBOptions(immutable_db_options_, mutable_db_options_)),
      env_options_for_compaction_(env_->OptimizeForCompactionTableWrite(
          env_options_, immutable_db_options_)),
@@ -300,6 +300,8 @@ Status DBImpl::CloseHelper() {
    TEST_SYNC_POINT("DBImpl::~DBImpl:WaitJob");
    bg_cv_.Wait();
  }
+  TEST_SYNC_POINT_CALLBACK("DBImpl::CloseHelper:PendingPurgeFinished",
+                           &files_grabbed_for_purge_);
  EraseThreadStatusDbInfo();
  flush_scheduler_.Clear();

@@ -353,10 +355,11 @@ Status DBImpl::CloseHelper() {
    uint64_t log_number = log.writer->get_log_number();
    Status s = log.ClearWriter();
    if (!s.ok()) {
-      ROCKS_LOG_WARN(immutable_db_options_.info_log,
-                     "Unable to Sync WAL file %s with error -- %s",
-                     LogFileName(immutable_db_options_.wal_dir, log_number).c_str(),
-                     s.ToString().c_str());
+      ROCKS_LOG_WARN(
+          immutable_db_options_.info_log,
+          "Unable to Sync WAL file %s with error -- %s",
+          LogFileName(immutable_db_options_.wal_dir, log_number).c_str(),
+          s.ToString().c_str());
      // Retain the first error
      if (ret.ok()) {
        ret = s;
@@ -512,7 +515,16 @@ void DBImpl::ScheduleBgLogWriterClose(JobContext* job_context) {
  }
 }

-Directory* DBImpl::Directories::GetDataDir(size_t path_id) {
+Directory* DBImpl::GetDataDir(ColumnFamilyData* cfd, size_t path_id) const {
+  assert(cfd);
+  Directory* ret_dir = cfd->GetDataDir(path_id);
+  if (ret_dir == nullptr) {
+    return directories_.GetDataDir(path_id);
+  }
+  return ret_dir;
+}
+
+Directory* DBImpl::Directories::GetDataDir(size_t path_id) const {
  assert(path_id < data_dirs_.size());
  Directory* ret_dir = data_dirs_[path_id].get();
  if (ret_dir == nullptr) {
@@ -522,9 +534,12 @@ Directory* DBImpl::Directories::GetDataDir(size_t path_id) {
  return ret_dir;
 }

-Status DBImpl::SetOptions(ColumnFamilyHandle* column_family,
+Status DBImpl::SetOptions(
+    ColumnFamilyHandle* column_family,
    const std::unordered_map<std::string, std::string>& options_map) {
 #ifdef ROCKSDB_LITE
+  (void)column_family;
+  (void)options_map;
  return Status::NotSupported("Not supported in ROCKSDB LITE");
 #else
  auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family)->cfd();
@@ -561,9 +576,9 @@ Status DBImpl::SetOptions(ColumnFamilyHandle* column_family,
  }
  sv_context.Clean();

-  ROCKS_LOG_INFO(immutable_db_options_.info_log,
-                 "SetOptions() on column family [%s], inputs:",
-                 cfd->GetName().c_str());
+  ROCKS_LOG_INFO(
+      immutable_db_options_.info_log,
+      "SetOptions() on column family [%s], inputs:", cfd->GetName().c_str());
  for (const auto& o : options_map) {
    ROCKS_LOG_INFO(immutable_db_options_.info_log, "%s: %s\n", o.first.c_str(),
                   o.second.c_str());
@@ -587,6 +602,7 @@ Status DBImpl::SetOptions(ColumnFamilyHandle* column_family,
 Status DBImpl::SetDBOptions(
    const std::unordered_map<std::string, std::string>& options_map) {
 #ifdef ROCKSDB_LITE
+  (void)options_map;
  return Status::NotSupported("Not supported in ROCKSDB LITE");
 #else
  if (options_map.empty()) {
@@ -613,7 +629,8 @@ Status DBImpl::SetDBOptions(
        MaybeScheduleFlushOrCompaction();
      }

-      write_controller_.set_max_delayed_write_rate(new_options.delayed_write_rate);
+      write_controller_.set_max_delayed_write_rate(
+          new_options.delayed_write_rate);
      table_cache_.get()->SetCapacity(new_options.max_open_files == -1
                                          ? TableCache::kInfiniteCapacity
                                          : new_options.max_open_files - 10);
@@ -693,7 +710,7 @@ int DBImpl::FindMinimumEmptyLevelFitting(
 }

 Status DBImpl::FlushWAL(bool sync) {
-  {
+  if (manual_wal_flush_) {
    // 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;
@@ -701,12 +718,20 @@ Status DBImpl::FlushWAL(bool sync) {
    if (!s.ok()) {
      ROCKS_LOG_ERROR(immutable_db_options_.info_log, "WAL flush error %s",
                      s.ToString().c_str());
+      // In case there is a fs error we should set it globally to prevent the
+      // future writes
+      WriteStatusCheck(s);
+      // whether sync or not, we should abort the rest of function upon error
+      return s;
    }
    if (!sync) {
      ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "FlushWAL sync=false");
      return s;
    }
  }
+  if (!sync) {
+    return Status::OK();
+  }
  // sync = true
  ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "FlushWAL sync=true");
  return SyncWAL();
@@ -774,12 +799,10 @@ Status DBImpl::SyncWAL() {
  return status;
 }

-void DBImpl::MarkLogsSynced(
-    uint64_t up_to, bool synced_dir, const Status& status) {
+void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
+                            const Status& status) {
  mutex_.AssertHeld();
-  if (synced_dir &&
-      logfile_number_ == up_to &&
-      status.ok()) {
+  if (synced_dir && logfile_number_ == up_to && status.ok()) {
    log_dir_synced_ = true;
  }
  for (auto it = logs_.begin(); it != logs_.end() && it->number <= up_to;) {
@@ -787,6 +810,8 @@ void DBImpl::MarkLogsSynced(
    assert(log.getting_synced);
    if (status.ok() && logs_.size() > 1) {
      logs_to_free_.push_back(log.ReleaseWriter());
+      // To modify logs_ both mutex_ and log_write_mutex_ must be held
+      InstrumentedMutexLock l(&log_write_mutex_);
      it = logs_.erase(it);
    } else {
      log.getting_synced = false;
@@ -853,14 +878,14 @@ void DBImpl::BackgroundCallPurge() {
    if (!purge_queue_.empty()) {
      auto purge_file = purge_queue_.begin();
      auto fname = purge_file->fname;
+      auto dir_to_sync = purge_file->dir_to_sync;
      auto type = purge_file->type;
      auto number = purge_file->number;
-      auto path_id = purge_file->path_id;
      auto job_id = purge_file->job_id;
      purge_queue_.pop_front();

      mutex_.Unlock();
-      DeleteObsoleteFileImpl(job_id, fname, type, number, path_id);
+      DeleteObsoleteFileImpl(job_id, fname, dir_to_sync, type, number);
      mutex_.Lock();
    } else {
      assert(!logs_to_free_queue_.empty());
@@ -944,7 +969,7 @@ InternalIterator* DBImpl::NewInternalIterator(
  MergeIteratorBuilder merge_iter_builder(
      &cfd->internal_comparator(), arena,
      !read_options.total_order_seek &&
-          cfd->ioptions()->prefix_extractor != nullptr);
+          super_version->mutable_cf_options.prefix_extractor != nullptr);
  // Collect iterator for mutable mem
  merge_iter_builder.AddIterator(
      super_version->mem->NewIterator(read_options, arena));
@@ -1016,8 +1041,8 @@ Status DBImpl::GetImpl(const ReadOptions& read_options,
    // Because prep_seq > snapshot => commit_seq > snapshot so if a snapshot is
    // specified we should be fine with skipping seq numbers that are greater
    // than that.
-    snapshot = reinterpret_cast<const SnapshotImpl*>(
-        read_options.snapshot)->number_;
+    snapshot =
+        reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)->number_;
  } else {
    // Since we get and reference the super version before getting
    // the snapshot number, without a mutex protection, it is possible
@@ -1095,7 +1120,6 @@ 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) {
-
  StopWatch sw(env_, stats_, DB_MULTIGET);
  PERF_TIMER_GUARD(get_snapshot_time);

@@ -1119,8 +1143,8 @@ std::vector<Status> DBImpl::MultiGet(

  mutex_.Lock();
  if (read_options.snapshot != nullptr) {
-    snapshot = reinterpret_cast<const SnapshotImpl*>(
-        read_options.snapshot)->number_;
+    snapshot =
+        reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)->number_;
  } else {
    snapshot = last_seq_same_as_publish_seq_
                   ? versions_->LastSequence()
@@ -1148,6 +1172,7 @@ std::vector<Status> DBImpl::MultiGet(
  // First look in the memtable, then in the immutable memtable (if any).
  // 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) {
    merge_context.Clear();
    Status& s = stat_list[i];
@@ -1169,11 +1194,11 @@ std::vector<Status> DBImpl::MultiGet(
      if (super_version->mem->Get(lkey, value, &s, &merge_context,
                                  &range_del_agg, read_options)) {
        done = true;
-        // TODO(?): RecordTick(stats_, MEMTABLE_HIT)?
+        RecordTick(stats_, MEMTABLE_HIT);
      } else if (super_version->imm->Get(lkey, value, &s, &merge_context,
                                         &range_del_agg, read_options)) {
        done = true;
-        // TODO(?): RecordTick(stats_, MEMTABLE_HIT)?
+        RecordTick(stats_, MEMTABLE_HIT);
      }
    }
    if (!done) {
@@ -1182,11 +1207,12 @@ std::vector<Status> DBImpl::MultiGet(
      super_version->current->Get(read_options, lkey, &pinnable_val, &s,
                                  &merge_context, &range_del_agg);
      value->assign(pinnable_val.data(), pinnable_val.size());
-      // TODO(?): RecordTick(stats_, MEMTABLE_MISS)?
+      RecordTick(stats_, MEMTABLE_MISS);
    }

    if (s.ok()) {
      bytes_read += value->size();
+      num_found++;
    }
  }

@@ -1214,6 +1240,7 @@ std::vector<Status> DBImpl::MultiGet(

  RecordTick(stats_, NUMBER_MULTIGET_CALLS);
  RecordTick(stats_, NUMBER_MULTIGET_KEYS_READ, num_keys);
+  RecordTick(stats_, NUMBER_MULTIGET_KEYS_FOUND, num_found);
  RecordTick(stats_, NUMBER_MULTIGET_BYTES_READ, bytes_read);
  MeasureTime(stats_, BYTES_PER_MULTIGET, bytes_read);
  PERF_COUNTER_ADD(multiget_read_bytes, bytes_read);
@@ -1301,6 +1328,17 @@ Status DBImpl::CreateColumnFamilyImpl(const ColumnFamilyOptions& cf_options,
  if (s.ok() && immutable_db_options_.allow_concurrent_memtable_write) {
    s = CheckConcurrentWritesSupported(cf_options);
  }
+  if (s.ok()) {
+    s = CheckCFPathsSupported(initial_db_options_, cf_options);
+  }
+  if (s.ok()) {
+    for (auto& cf_path : cf_options.cf_paths) {
+      s = env_->CreateDirIfMissing(cf_path.path);
+      if (!s.ok()) {
+        break;
+      }
+    }
+  }
  if (!s.ok()) {
    return s;
  }
@@ -1332,13 +1370,19 @@ Status DBImpl::CreateColumnFamilyImpl(const ColumnFamilyOptions& cf_options,
                                 &cf_options);
      write_thread_.ExitUnbatched(&w);
    }
+    if (s.ok()) {
+      auto* cfd =
+          versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name);
+      assert(cfd != nullptr);
+      s = cfd->AddDirectories();
+    }
    if (s.ok()) {
      single_column_family_mode_ = false;
      auto* cfd =
          versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name);
      assert(cfd != nullptr);
-      InstallSuperVersionAndScheduleWork(
-              cfd, &sv_context, *cfd->GetLatestMutableCFOptions());
+      InstallSuperVersionAndScheduleWork(cfd, &sv_context,
+                                         *cfd->GetLatestMutableCFOptions());

      if (!cfd->mem()->IsSnapshotSupported()) {
        is_snapshot_supported_ = false;
@@ -1420,8 +1464,8 @@ Status DBImpl::DropColumnFamilyImpl(ColumnFamilyHandle* column_family) {
      // we drop column family from a single write thread
      WriteThread::Writer w;
      write_thread_.EnterUnbatched(&w, &mutex_);
-      s = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(),
-                                 &edit, &mutex_);
+      s = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(), &edit,
+                                 &mutex_);
      write_thread_.ExitUnbatched(&w);
    }
    if (s.ok()) {
@@ -1471,7 +1515,7 @@ bool DBImpl::KeyMayExist(const ReadOptions& read_options,
    *value_found = true;
  }
  ReadOptions roptions = read_options;
-  roptions.read_tier = kBlockCacheTier; // read from block cache only
+  roptions.read_tier = kBlockCacheTier;  // read from block cache only
  PinnableSlice pinnable_val;
  auto s = GetImpl(roptions, column_family, key, &pinnable_val, value_found);
  value->assign(pinnable_val.data(), pinnable_val.size());
@@ -1494,17 +1538,17 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
  if (immutable_db_options_.preserve_deletes &&
      read_options.iter_start_seqnum > 0 &&
      read_options.iter_start_seqnum < preserve_deletes_seqnum_.load()) {
-        return NewErrorIterator(Status::InvalidArgument(
-          "Iterator requested internal keys which are too old and are not"
-          " guaranteed to be preserved, try larger iter_start_seqnum opt."));
-      }
+    return NewErrorIterator(Status::InvalidArgument(
+        "Iterator requested internal keys which are too old and are not"
+        " guaranteed to be preserved, try larger iter_start_seqnum opt."));
+  }
  auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
  auto cfd = cfh->cfd();
  ReadCallback* read_callback = nullptr;  // No read callback provided.
  if (read_options.managed) {
 #ifdef ROCKSDB_LITE
    // not supported in lite version
-    result =  NewErrorIterator(Status::InvalidArgument(
+    result = NewErrorIterator(Status::InvalidArgument(
        "Managed Iterators not supported in RocksDBLite."));
 #else
    if ((read_options.tailing) || (read_options.snapshot != nullptr) ||
@@ -1513,7 +1557,7 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    } else {
      // Managed iter not supported
      result = NewErrorIterator(Status::InvalidArgument(
-        "Managed Iterators not supported without snapshots."));
+          "Managed Iterators not supported without snapshots."));
    }
 #endif
  } else if (read_options.tailing) {
@@ -1525,8 +1569,8 @@ Iterator* DBImpl::NewIterator(const ReadOptions& read_options,
    SuperVersion* sv = cfd->GetReferencedSuperVersion(&mutex_);
    auto iter = new ForwardIterator(this, read_options, cfd, sv);
    result = NewDBIterator(
-        env_, read_options, *cfd->ioptions(), cfd->user_comparator(), iter,
-        kMaxSequenceNumber,
+        env_, read_options, *cfd->ioptions(), sv->mutable_cf_options,
+        cfd->user_comparator(), iter, kMaxSequenceNumber,
        sv->mutable_cf_options.max_sequential_skip_in_iterations,
        read_callback);
 #endif
@@ -1593,7 +1637,7 @@ ArenaWrappedDBIter* DBImpl::NewIteratorImpl(const ReadOptions& read_options,
  // likely that any iterator pointer is close to the iterator it points to so
  // that they are likely to be in the same cache line and/or page.
  ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, *cfd->ioptions(), snapshot,
+      env_, read_options, *cfd->ioptions(), sv->mutable_cf_options, snapshot,
      sv->mutable_cf_options.max_sequential_skip_in_iterations,
      sv->version_number, read_callback,
      ((read_options.snapshot != nullptr) ? nullptr : this), cfd, allow_blob,
@@ -1644,8 +1688,8 @@ Status DBImpl::NewIterators(
      SuperVersion* sv = cfd->GetReferencedSuperVersion(&mutex_);
      auto iter = new ForwardIterator(this, read_options, cfd, sv);
      iterators->push_back(NewDBIterator(
-          env_, read_options, *cfd->ioptions(), cfd->user_comparator(), iter,
-          kMaxSequenceNumber,
+          env_, read_options, *cfd->ioptions(), sv->mutable_cf_options,
+          cfd->user_comparator(), iter, kMaxSequenceNumber,
          sv->mutable_cf_options.max_sequential_skip_in_iterations,
          read_callback));
    }
@@ -1658,8 +1702,8 @@ Status DBImpl::NewIterators(
                        ? read_options.snapshot->GetSequenceNumber()
                        : versions_->LastSequence();
    for (size_t i = 0; i < column_families.size(); ++i) {
-      auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(
-          column_families[i])->cfd();
+      auto* cfd =
+          reinterpret_cast<ColumnFamilyHandleImpl*>(column_families[i])->cfd();
      iterators->push_back(
          NewIteratorImpl(read_options, cfd, snapshot, read_callback));
    }
@@ -1676,7 +1720,7 @@ const Snapshot* DBImpl::GetSnapshotForWriteConflictBoundary() {
 }
 #endif  // ROCKSDB_LITE

-const Snapshot* DBImpl::GetSnapshotImpl(bool is_write_conflict_boundary) {
+SnapshotImpl* DBImpl::GetSnapshotImpl(bool is_write_conflict_boundary) {
  int64_t unix_time = 0;
  env_->GetCurrentTime(&unix_time);  // Ignore error
  SnapshotImpl* s = new SnapshotImpl;
@@ -1766,13 +1810,9 @@ Status DBImpl::GetPropertiesOfTablesInRange(ColumnFamilyHandle* column_family,

 #endif  // ROCKSDB_LITE

-const std::string& DBImpl::GetName() const {
-  return dbname_;
-}
+const std::string& DBImpl::GetName() const { return dbname_; }

-Env* DBImpl::GetEnv() const {
-  return env_;
-}
+Env* DBImpl::GetEnv() const { return env_; }

 Options DBImpl::GetOptions(ColumnFamilyHandle* column_family) const {
  InstrumentedMutexLock l(&mutex_);
@@ -2145,9 +2185,9 @@ Status DBImpl::DeleteFile(std::string name) {
    status = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(),
                                    &edit, &mutex_, directories_.GetDbDir());
    if (status.ok()) {
-      InstallSuperVersionAndScheduleWork(
-          cfd, &job_context.superversion_context,
-          *cfd->GetLatestMutableCFOptions());
+      InstallSuperVersionAndScheduleWork(cfd, &job_context.superversion_context,
+                                         *cfd->GetLatestMutableCFOptions(),
+                                         FlushReason::kDeleteFiles);
    }
    FindObsoleteFiles(&job_context, false);
  }  // lock released here
@@ -2198,9 +2238,9 @@ Status DBImpl::DeleteFilesInRanges(ColumnFamilyHandle* column_family,
          end_key = &end_storage;
        }

-        vstorage->GetCleanInputsWithinInterval(i, begin_key, end_key,
-                                               &level_files, -1 /* hint_index */,
-                                               nullptr /* file_index */);
+        vstorage->GetCleanInputsWithinInterval(
+            i, begin_key, end_key, &level_files, -1 /* hint_index */,
+            nullptr /* file_index */);
        FileMetaData* level_file;
        for (uint32_t j = 0; j < level_files.size(); j++) {
          level_file = level_files[j];
@@ -2211,7 +2251,8 @@ Status DBImpl::DeleteFilesInRanges(ColumnFamilyHandle* column_family,
            continue;
          }
          if (!include_end && end != nullptr &&
-              cfd->user_comparator()->Compare(level_file->largest.user_key(), *end) == 0) {
+              cfd->user_comparator()->Compare(level_file->largest.user_key(),
+                                              *end) == 0) {
            continue;
          }
          edit.SetColumnFamily(cfd->GetID());
@@ -2229,9 +2270,9 @@ Status DBImpl::DeleteFilesInRanges(ColumnFamilyHandle* column_family,
    status = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(),
                                    &edit, &mutex_, directories_.GetDbDir());
    if (status.ok()) {
-      InstallSuperVersionAndScheduleWork(
-          cfd, &job_context.superversion_context,
-          *cfd->GetLatestMutableCFOptions());
+      InstallSuperVersionAndScheduleWork(cfd, &job_context.superversion_context,
+                                         *cfd->GetLatestMutableCFOptions(),
+                                         FlushReason::kDeleteFiles);
    }
    for (auto* deleted_file : deleted_files) {
      deleted_file->being_compacted = false;
@@ -2255,9 +2296,8 @@ void DBImpl::GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata) {
  versions_->GetLiveFilesMetaData(metadata);
 }

-void DBImpl::GetColumnFamilyMetaData(
-    ColumnFamilyHandle* column_family,
-    ColumnFamilyMetaData* cf_meta) {
+void DBImpl::GetColumnFamilyMetaData(ColumnFamilyHandle* column_family,
+                                     ColumnFamilyMetaData* cf_meta) {
  assert(column_family);
  auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family)->cfd();
  auto* sv = GetAndRefSuperVersion(cfd);
@@ -2383,10 +2423,10 @@ Status DB::ListColumnFamilies(const DBOptions& db_options,
  return VersionSet::ListColumnFamilies(column_families, name, db_options.env);
 }

-Snapshot::~Snapshot() {
-}
+Snapshot::~Snapshot() {}

-Status DestroyDB(const std::string& dbname, const Options& options) {
+Status DestroyDB(const std::string& dbname, const Options& options,
+                 const std::vector<ColumnFamilyDescriptor>& column_families) {
  ImmutableDBOptions soptions(SanitizeOptions(dbname, options));
  Env* env = soptions.env;
  std::vector<std::string> filenames;
@@ -2404,15 +2444,15 @@ Status DestroyDB(const std::string& dbname, const Options& options) {
    uint64_t number;
    FileType type;
    InfoLogPrefix info_log_prefix(!soptions.db_log_dir.empty(), dbname);
-    for (size_t i = 0; i < filenames.size(); i++) {
-      if (ParseFileName(filenames[i], &number, info_log_prefix.prefix, &type) &&
-          type != kDBLockFile) {  // Lock file will be deleted at end
+    for (const auto& fname : filenames) {
+      if (ParseFileName(fname, &number, info_log_prefix.prefix, &type) &&
+        type != kDBLockFile) {  // Lock file will be deleted at end
        Status del;
-        std::string path_to_delete = dbname + "/" + filenames[i];
+        std::string path_to_delete = dbname + "/" + fname;
        if (type == kMetaDatabase) {
          del = DestroyDB(path_to_delete, options);
        } else if (type == kTableFile) {
-          del = DeleteSSTFile(&soptions, path_to_delete, 0);
+          del = DeleteSSTFile(&soptions, path_to_delete, dbname);
        } else {
          del = env->DeleteFile(path_to_delete);
        }
@@ -2422,59 +2462,82 @@ Status DestroyDB(const std::string& dbname, const Options& options) {
      }
    }

-    for (size_t path_id = 0; path_id < options.db_paths.size(); path_id++) {
-      const auto& db_path = options.db_paths[path_id];
-      env->GetChildren(db_path.path, &filenames);
-      for (size_t i = 0; i < filenames.size(); i++) {
-        if (ParseFileName(filenames[i], &number, &type) &&
+    std::vector<std::string> paths;
+
+    for (const auto& path : options.db_paths) {
+      paths.emplace_back(path.path);
+    }
+    for (const auto& cf : column_families) {
+      for (const auto& path : cf.options.cf_paths) {
+        paths.emplace_back(path.path);
+      }
+    }
+
+    // Remove duplicate paths.
+    // Note that we compare only the actual paths but not path ids.
+    // This reason is that same path can appear at different path_ids
+    // for different column families.
+    std::sort(paths.begin(), paths.end());
+    paths.erase(std::unique(paths.begin(), paths.end()), paths.end());
+
+    for (const auto& path : paths) {
+      if (env->GetChildren(path, &filenames).ok()) {
+        for (const auto& fname : filenames) {
+          if (ParseFileName(fname, &number, &type) &&
            type == kTableFile) {  // Lock file will be deleted at end
-          std::string table_path = db_path.path + "/" + filenames[i];
-          Status del = DeleteSSTFile(&soptions, table_path,
-                                     static_cast<uint32_t>(path_id));
-          if (result.ok() && !del.ok()) {
-            result = del;
+            std::string table_path = path + "/" + fname;
+            Status del = DeleteSSTFile(&soptions, table_path, dbname);
+            if (result.ok() && !del.ok()) {
+              result = del;
+            }
          }
        }
+        env->DeleteDir(path);
      }
    }

    std::vector<std::string> walDirFiles;
    std::string archivedir = ArchivalDirectory(dbname);
+    bool wal_dir_exists = false;
    if (dbname != soptions.wal_dir) {
-      env->GetChildren(soptions.wal_dir, &walDirFiles);
+      wal_dir_exists = env->GetChildren(soptions.wal_dir, &walDirFiles).ok();
      archivedir = ArchivalDirectory(soptions.wal_dir);
    }

-    // Delete log files in the WAL dir
-    for (const auto& file : walDirFiles) {
-      if (ParseFileName(file, &number, &type) && type == kLogFile) {
-        Status del = env->DeleteFile(LogFileName(soptions.wal_dir, number));
-        if (result.ok() && !del.ok()) {
-          result = del;
-        }
-      }
-    }
-
+    // Archive dir may be inside wal dir or dbname and should be
+    // processed and removed before those otherwise we have issues
+    // removing them
    std::vector<std::string> archiveFiles;
-    env->GetChildren(archivedir, &archiveFiles);
-    // Delete archival files.
-    for (size_t i = 0; i < archiveFiles.size(); ++i) {
-      if (ParseFileName(archiveFiles[i], &number, &type) &&
+    if (env->GetChildren(archivedir, &archiveFiles).ok()) {
+      // Delete archival files.
+      for (const auto& file : archiveFiles) {
+        if (ParseFileName(file, &number, &type) &&
          type == kLogFile) {
-        Status del = env->DeleteFile(archivedir + "/" + archiveFiles[i]);
-        if (result.ok() && !del.ok()) {
-          result = del;
+          Status del = env->DeleteFile(archivedir + "/" + file);
+          if (result.ok() && !del.ok()) {
+            result = del;
+          }
        }
      }
+      env->DeleteDir(archivedir);
    }

-    // ignore case where no archival directory is present
-    env->DeleteDir(archivedir);
+    // Delete log files in the WAL dir
+    if (wal_dir_exists) {
+      for (const auto& file : walDirFiles) {
+        if (ParseFileName(file, &number, &type) && type == kLogFile) {
+          Status del = env->DeleteFile(LogFileName(soptions.wal_dir, number));
+          if (result.ok() && !del.ok()) {
+            result = del;
+          }
+        }
+      }
+      env->DeleteDir(soptions.wal_dir);
+    }

    env->UnlockFile(lock);  // Ignore error since state is already gone
    env->DeleteFile(lockname);
    env->DeleteDir(dbname);  // Ignore error in case dir contains other files
-    env->DeleteDir(soptions.wal_dir);
  }
  return result;
 }
@@ -2536,6 +2599,9 @@ Status DBImpl::WriteOptionsFile(bool need_mutex_lock,
                             s.ToString().c_str());
    }
  }
+#else
+  (void)need_mutex_lock;
+  (void)need_enter_write_thread;
 #endif  // !ROCKSDB_LITE
  return Status::OK();
 }
@@ -2604,22 +2670,21 @@ Status DBImpl::RenameTempFileToOptionsFile(const std::string& file_name) {
  DeleteObsoleteOptionsFiles();
  return s;
 #else
+  (void)file_name;
  return Status::OK();
 #endif  // !ROCKSDB_LITE
 }

 #ifdef ROCKSDB_USING_THREAD_STATUS

-void DBImpl::NewThreadStatusCfInfo(
-    ColumnFamilyData* cfd) const {
+void DBImpl::NewThreadStatusCfInfo(ColumnFamilyData* cfd) const {
  if (immutable_db_options_.enable_thread_tracking) {
    ThreadStatusUtil::NewColumnFamilyInfo(this, cfd, cfd->GetName(),
                                          cfd->ioptions()->env);
  }
 }

-void DBImpl::EraseThreadStatusCfInfo(
-    ColumnFamilyData* cfd) const {
+void DBImpl::EraseThreadStatusCfInfo(ColumnFamilyData* cfd) const {
  if (immutable_db_options_.enable_thread_tracking) {
    ThreadStatusUtil::EraseColumnFamilyInfo(cfd);
  }
@@ -2632,21 +2697,16 @@ void DBImpl::EraseThreadStatusDbInfo() const {
 }

 #else
-void DBImpl::NewThreadStatusCfInfo(
-    ColumnFamilyData* cfd) const {
-}
+void DBImpl::NewThreadStatusCfInfo(ColumnFamilyData* /*cfd*/) const {}

-void DBImpl::EraseThreadStatusCfInfo(
-    ColumnFamilyData* cfd) const {
-}
+void DBImpl::EraseThreadStatusCfInfo(ColumnFamilyData* /*cfd*/) const {}

-void DBImpl::EraseThreadStatusDbInfo() const {
-}
+void DBImpl::EraseThreadStatusDbInfo() const {}
 #endif  // ROCKSDB_USING_THREAD_STATUS

 //
 // A global method that can dump out the build version
-void DumpRocksDBBuildVersion(Logger * log) {
+void DumpRocksDBBuildVersion(Logger* log) {
 #if !defined(IOS_CROSS_COMPILE)
  // if we compile with Xcode, we don't run build_detect_version, so we don't
  // generate util/build_version.cc
@@ -2783,7 +2843,7 @@ Status DBImpl::IngestExternalFile(
  if (ingestion_options.ingest_behind) {
    if (!immutable_db_options_.allow_ingest_behind) {
      return Status::InvalidArgument(
-        "Can't ingest_behind file in DB with allow_ingest_behind=false");
+          "Can't ingest_behind file in DB with allow_ingest_behind=false");
    }
  }

@@ -2803,7 +2863,9 @@ Status DBImpl::IngestExternalFile(
    pending_output_elem = CaptureCurrentFileNumberInPendingOutputs();
  }

-  status = ingestion_job.Prepare(external_files);
+  SuperVersion* super_version = cfd->GetReferencedSuperVersion(&mutex_);
+  status = ingestion_job.Prepare(external_files, super_version);
+  CleanupSuperVersion(super_version);
  if (!status.ok()) {
    return status;
  }
@@ -2859,8 +2921,8 @@ Status DBImpl::IngestExternalFile(
                                 &mutex_, directories_.GetDbDir());
    }
    if (status.ok()) {
-      InstallSuperVersionAndScheduleWork(cfd, &sv_context,
-                                         *mutable_cf_options);
+      InstallSuperVersionAndScheduleWork(cfd, &sv_context, *mutable_cf_options,
+                                         FlushReason::kExternalFileIngestion);
    }

    // Resume writes to the DB
@@ -2916,11 +2978,12 @@ Status DBImpl::VerifyChecksum() {
  }
  for (auto& sv : sv_list) {
    VersionStorageInfo* vstorage = sv->current->storage_info();
+    ColumnFamilyData* cfd = sv->current->cfd();
    for (int i = 0; i < vstorage->num_non_empty_levels() && s.ok(); i++) {
      for (size_t j = 0; j < vstorage->LevelFilesBrief(i).num_files && s.ok();
           j++) {
        const auto& fd = vstorage->LevelFilesBrief(i).files[j].fd;
-        std::string fname = TableFileName(immutable_db_options_.db_paths,
+        std::string fname = TableFileName(cfd->ioptions()->cf_paths,
                                          fd.GetNumber(), fd.GetPathId());
        s = rocksdb::VerifySstFileChecksum(options, env_options, fname);
      }
@@ -2938,7 +3001,7 @@ Status DBImpl::VerifyChecksum() {
      }
    }
    for (auto cfd : cfd_list) {
-        cfd->Unref();
+      cfd->Unref();
    }
  }
  return s;
@@ -2974,5 +3037,4 @@ void DBImpl::WaitForIngestFile() {
 }

 #endif  // ROCKSDB_LITE
-
 }  // namespace rocksdb
@@ -27,6 +27,7 @@
 #include "db/flush_scheduler.h"
 #include "db/internal_stats.h"
 #include "db/log_writer.h"
+#include "db/logs_with_prep_tracker.h"
 #include "db/pre_release_callback.h"
 #include "db/read_callback.h"
 #include "db/snapshot_checker.h"
@@ -220,9 +221,12 @@ class DBImpl : public DB {
  virtual Status Flush(const FlushOptions& options,
                       ColumnFamilyHandle* column_family) override;
  virtual Status FlushWAL(bool sync) override;
+  bool TEST_WALBufferIsEmpty();
  virtual Status SyncWAL() override;

  virtual SequenceNumber GetLatestSequenceNumber() const override;
+  // REQUIRES: joined the main write queue if two_write_queues is disabled, and
+  // the second write queue otherwise.
  virtual void SetLastPublishedSequence(SequenceNumber seq);
  // Returns LastSequence in last_seq_same_as_publish_seq_
  // mode and LastAllocatedSequence otherwise. This is useful when visiblility
@@ -340,6 +344,7 @@ class DBImpl : public DB {

  Status RunManualCompaction(ColumnFamilyData* cfd, int input_level,
                             int output_level, uint32_t output_path_id,
+                             uint32_t max_subcompactions,
                             const Slice* begin, const Slice* end,
                             bool exclusive,
                             bool disallow_trivial_move = false);
@@ -351,6 +356,10 @@ class DBImpl : public DB {
      Arena* arena, RangeDelAggregator* range_del_agg,
      ColumnFamilyHandle* column_family = nullptr);

+  LogsWithPrepTracker* logs_with_prep_tracker() {
+    return &logs_with_prep_tracker_;
+  }
+
 #ifndef NDEBUG
  // Extra methods (for testing) that are not in the public DB interface
  // Implemented in db_impl_debug.cc
@@ -362,9 +371,7 @@ class DBImpl : public DB {

  void TEST_SwitchWAL();

-  bool TEST_UnableToFlushOldestLog() {
-    return unable_to_flush_oldest_log_;
-  }
+  bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; }

  bool TEST_IsLogGettingFlushed() {
    return alive_log_files_.begin()->getting_flushed;
@@ -476,7 +483,7 @@ class DBImpl : public DB {
  // It is not necessary to hold the mutex when invoking this method.
  // If FindObsoleteFiles() was run, we need to also run
  // PurgeObsoleteFiles(), even if disable_delete_obsolete_files_ is true
-  void PurgeObsoleteFiles(const JobContext& background_contet,
+  void PurgeObsoleteFiles(JobContext& background_contet,
                          bool schedule_only = false);

  void SchedulePurge();
@@ -591,7 +598,7 @@ class DBImpl : public DB {
                                  size_t batch_cnt) {
    recovered_transactions_[name] =
        new RecoveredTransaction(log, name, batch, seq, batch_cnt);
-    MarkLogAsContainingPrepSection(log);
+    logs_with_prep_tracker_.MarkLogAsContainingPrepSection(log);
  }

  void DeleteRecoveredTransaction(const std::string& name) {
@@ -599,7 +606,7 @@ class DBImpl : public DB {
    assert(it != recovered_transactions_.end());
    auto* trx = it->second;
    recovered_transactions_.erase(it);
-    MarkLogAsHavingPrepSectionFlushed(trx->log_number_);
+    logs_with_prep_tracker_.MarkLogAsHavingPrepSectionFlushed(trx->log_number_);
    delete trx;
  }

@@ -611,14 +618,15 @@ class DBImpl : public DB {
    recovered_transactions_.clear();
  }

-  void MarkLogAsHavingPrepSectionFlushed(uint64_t log);
-  void MarkLogAsContainingPrepSection(uint64_t log);
  void AddToLogsToFreeQueue(log::Writer* log_writer) {
    logs_to_free_queue_.push_back(log_writer);
  }

  void SetSnapshotChecker(SnapshotChecker* snapshot_checker);

+  // Not thread-safe.
+  void SetRecoverableStatePreReleaseCallback(PreReleaseCallback* callback);
+
  InstrumentedMutex* mutex() { return &mutex_; }

  Status NewDB();
@@ -631,6 +639,9 @@ class DBImpl : public DB {

  virtual Status Close() override;

+  static Status CreateAndNewDirectory(Env* env, const std::string& dirname,
+                                      std::unique_ptr<Directory>* directory);
+
 protected:
  Env* const env_;
  const std::string dbname_;
@@ -683,14 +694,20 @@ class DBImpl : public DB {
  void EraseThreadStatusDbInfo() const;

  // If disable_memtable is set the application logic must guarantee that the
-  // batch will still be skipped from memtable during the recovery. In
-  // WriteCommitted it is guarnateed since disable_memtable is used for prepare
-  // batch which will be written to memtable later during the commit, and in
-  // WritePrepared it is guaranteed since it will be used only for WAL markers
-  // which will never be written to memtable.
-  // batch_cnt is expected to be non-zero in seq_per_batch mode and indicates
-  // the number of sub-patches. A sub-patch is a subset of the write batch that
-  // does not have duplicate keys.
+  // batch will still be skipped from memtable during the recovery. An excption
+  // to this is seq_per_batch_ mode, in which since each batch already takes one
+  // seq, it is ok for the batch to write to memtable during recovery as long as
+  // it only takes one sequence number: i.e., no duplicate keys.
+  // In WriteCommitted it is guarnateed since disable_memtable is used for
+  // prepare batch which will be written to memtable later during the commit,
+  // and in WritePrepared it is guaranteed since it will be used only for WAL
+  // markers which will never be written to memtable. If the commit marker is
+  // accompanied with CommitTimeWriteBatch that is not written to memtable as
+  // long as it has no duplicate keys, it does not violate the one-seq-per-batch
+  // policy.
+  // batch_cnt is expected to be non-zero in seq_per_batch mode and
+  // indicates the number of sub-patches. A sub-patch is a subset of the write
+  // batch that does not have duplicate keys.
  Status WriteImpl(const WriteOptions& options, WriteBatch* updates,
                   WriteCallback* callback = nullptr,
                   uint64_t* log_used = nullptr, uint64_t log_ref = 0,
@@ -713,8 +730,6 @@ class DBImpl : public DB {
                          uint64_t* seq_used = nullptr, size_t batch_cnt = 0,
                          PreReleaseCallback* pre_release_callback = nullptr);

-  uint64_t FindMinLogContainingOutstandingPrep();
-  uint64_t FindMinPrepLogReferencedByMemTable();
  // write cached_recoverable_state_ to memtable if it is not empty
  // The writer must be the leader in write_thread_ and holding mutex_
  Status WriteRecoverableState();
@@ -726,6 +741,7 @@ class DBImpl : public DB {
  friend class DB;
  friend class InternalStats;
  friend class PessimisticTransaction;
+  friend class TransactionBaseImpl;
  friend class WriteCommittedTxn;
  friend class WritePreparedTxn;
  friend class WritePreparedTxnDB;
@@ -735,6 +751,7 @@ class DBImpl : public DB {
 #endif
  friend struct SuperVersion;
  friend class CompactedDBImpl;
+  friend class DBTest_ConcurrentFlushWAL_Test;
 #ifndef NDEBUG
  friend class DBTest2_ReadCallbackTest_Test;
  friend class WriteCallbackTest_WriteWithCallbackTest_Test;
@@ -782,7 +799,8 @@ class DBImpl : public DB {
  void DeleteObsoleteFiles();
  // Delete obsolete files and log status and information of file deletion
  void DeleteObsoleteFileImpl(int job_id, const std::string& fname,
-                              FileType type, uint64_t number, uint32_t path_id);
+                              const std::string& path_to_sync, FileType type,
+                              uint64_t number);

  // Background process needs to call
  //     auto x = CaptureCurrentFileNumberInPendingOutputs()
@@ -833,7 +851,8 @@ class DBImpl : public DB {

  Status ScheduleFlushes(WriteContext* context);

-  Status SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context);
+  Status SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
+                        FlushReason flush_reason = FlushReason::kOthers);

  // Force current memtable contents to be flushed.
  Status FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& options,
@@ -873,7 +892,7 @@ class DBImpl : public DB {
                              size_t seq_inc);

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

  // Used by WriteImpl to update bg_error_ in case of memtable insert error.
  void MemTableInsertStatusCheck(const Status& memtable_insert_status);
@@ -902,8 +921,8 @@ class DBImpl : public DB {
  void MaybeScheduleFlushOrCompaction();
  void SchedulePendingFlush(ColumnFamilyData* cfd, FlushReason flush_reason);
  void SchedulePendingCompaction(ColumnFamilyData* cfd);
-  void SchedulePendingPurge(std::string fname, FileType type, uint64_t number,
-                            uint32_t path_id, int job_id);
+  void SchedulePendingPurge(std::string fname, std::string dir_to_sync,
+                            FileType type, uint64_t number, int job_id);
  static void BGWorkCompaction(void* arg);
  // Runs a pre-chosen universal compaction involving bottom level in a
  // separate, bottom-pri thread pool.
@@ -921,6 +940,9 @@ class DBImpl : public DB {
  Status BackgroundFlush(bool* madeProgress, JobContext* job_context,
                         LogBuffer* log_buffer);

+  bool EnoughRoomForCompaction(const std::vector<CompactionInputFiles>& inputs,
+                               bool* sfm_bookkeeping, LogBuffer* log_buffer);
+
  void PrintStatistics();

  // dump rocksdb.stats to LOG
@@ -945,10 +967,12 @@ class DBImpl : public DB {
  // helper function to call after some of the logs_ were synced
  void MarkLogsSynced(uint64_t up_to, bool synced_dir, const Status& status);

-  const Snapshot* GetSnapshotImpl(bool is_write_conflict_boundary);
+  SnapshotImpl* GetSnapshotImpl(bool is_write_conflict_boundary);

  uint64_t GetMaxTotalWalSize() const;

+  Directory* GetDataDir(ColumnFamilyData* cfd, size_t path_id) const;
+
  Status CloseHelper();

  // table_cache_ provides its own synchronization
@@ -1086,7 +1110,7 @@ class DBImpl : public DB {
                          const std::string& wal_dir,
                          const std::vector<DbPath>& data_paths);

-    Directory* GetDataDir(size_t path_id);
+    Directory* GetDataDir(size_t path_id) const;

    Directory* GetWalDir() {
      if (wal_dir_) {
@@ -1101,9 +1125,6 @@ class DBImpl : public DB {
    std::unique_ptr<Directory> db_dir_;
    std::vector<std::unique_ptr<Directory>> data_dirs_;
    std::unique_ptr<Directory> wal_dir_;
-
-    Status CreateAndNewDirectory(Env* env, const std::string& dirname,
-                                 std::unique_ptr<Directory>* directory) const;
  };

  Directories directories_;
@@ -1145,13 +1166,13 @@ class DBImpl : public DB {
  // purge_queue_
  struct PurgeFileInfo {
    std::string fname;
+    std::string dir_to_sync;
    FileType type;
    uint64_t number;
-    uint32_t path_id;
    int job_id;
-    PurgeFileInfo(std::string fn, FileType t, uint64_t num, uint32_t pid,
+    PurgeFileInfo(std::string fn, std::string d, FileType t, uint64_t num,
                  int jid)
-        : fname(fn), type(t), number(num), path_id(pid), job_id(jid) {}
+        : fname(fn), dir_to_sync(d), type(t), number(num), job_id(jid) {}
  };

  // flush_queue_ and compaction_queue_ hold column families that we need to
@@ -1182,6 +1203,10 @@ class DBImpl : public DB {
  // A queue to store filenames of the files to be purged
  std::deque<PurgeFileInfo> purge_queue_;

+  // A vector to store the file numbers that have been assigned to certain
+  // JobContext. Current implementation tracks ssts only.
+  std::vector<uint64_t> files_grabbed_for_purge_;
+
  // A queue to store log writers to close
  std::deque<log::Writer*> logs_to_free_queue_;
  int unscheduled_flushes_;
@@ -1277,7 +1302,7 @@ class DBImpl : public DB {
  // We must attempt to free the dependent memtables again
  // at a later time after the transaction in the oldest
  // log is fully commited.
-  bool unable_to_flush_oldest_log_;
+  bool unable_to_release_oldest_log_;

  static const int KEEP_LOG_FILE_NUM = 1000;
  // MSVC version 1800 still does not have constexpr for ::max()
@@ -1314,38 +1339,16 @@ class DBImpl : public DB {
  // Indicate DB was opened successfully
  bool opened_successfully_;

-  // REQUIRES: logs_with_prep_mutex_ held
-  //
-  // sorted list of log numbers still containing prepared data.
-  // this is used by FindObsoleteFiles to determine which
-  // flushed logs we must keep around because they still
-  // contain prepared data which has not been committed or rolled back
-  struct LogCnt {
-    uint64_t log;  // the log number
-    uint64_t cnt;  // number of prepared sections in the log
-  };
-  std::vector<LogCnt> logs_with_prep_;
-  std::mutex logs_with_prep_mutex_;
-
-  // REQUIRES: prepared_section_completed_mutex_ held
-  //
-  // to be used in conjunction with logs_with_prep_.
-  // once a transaction with data in log L is committed or rolled back
-  // rather than updating logs_with_prep_ directly we keep track of that
-  // in prepared_section_completed_ which maps LOG -> instance_count. This helps
-  // avoiding contention between a commit thread and the prepare threads.
-  //
-  // when trying to determine the minimum log still active we first
-  // consult logs_with_prep_. while that root value maps to
-  // an equal value in prepared_section_completed_ we erase the log from
-  // both logs_with_prep_ and prepared_section_completed_.
-  std::unordered_map<uint64_t, uint64_t> prepared_section_completed_;
-  std::mutex prepared_section_completed_mutex_;
+  LogsWithPrepTracker logs_with_prep_tracker_;

  // Callback for compaction to check if a key is visible to a snapshot.
  // REQUIRES: mutex held
  std::unique_ptr<SnapshotChecker> snapshot_checker_;

+  // Callback for when the cached_recoverable_state_ is written to memtable
+  // Only to be set during initialization
+  std::unique_ptr<PreReleaseCallback> recoverable_state_pre_release_callback_;
+
  // No copying allowed
  DBImpl(const DBImpl&);
  void operator=(const DBImpl&);
@@ -1359,7 +1362,8 @@ class DBImpl : public DB {
  // state needs flush or compaction.
  void InstallSuperVersionAndScheduleWork(
      ColumnFamilyData* cfd, SuperVersionContext* sv_context,
-      const MutableCFOptions& mutable_cf_options);
+      const MutableCFOptions& mutable_cf_options,
+      FlushReason flush_reason = FlushReason::kOthers);

 #ifndef ROCKSDB_LITE
  using DB::GetPropertiesOfAllTables;
@@ -1384,6 +1388,9 @@ class DBImpl : public DB {
  bool HaveManualCompaction(ColumnFamilyData* cfd);
  bool MCOverlap(ManualCompactionState* m, ManualCompactionState* m1);

+  bool ShouldPurge(uint64_t file_number) const;
+  void MarkAsGrabbedForPurge(uint64_t file_number);
+
  size_t GetWalPreallocateBlockSize(uint64_t write_buffer_size) const;
  Env::WriteLifeTimeHint CalculateWALWriteHint() {
    return Env::WLTH_SHORT;
@@ -1428,6 +1435,25 @@ extern CompressionType GetCompressionFlush(
    const ImmutableCFOptions& ioptions,
    const MutableCFOptions& mutable_cf_options);

+// Return the earliest log file to keep after the memtable flush is
+// finalized.
+// `cfd_to_flush` is the column family whose memtable (specified in
+// `memtables_to_flush`) will be flushed and thus will not depend on any WAL
+// file.
+// The function is only applicable to 2pc mode.
+extern uint64_t PrecomputeMinLogNumberToKeep(
+    VersionSet* vset, const ColumnFamilyData& cfd_to_flush,
+    autovector<VersionEdit*> edit_list,
+    const autovector<MemTable*>& memtables_to_flush,
+    LogsWithPrepTracker* prep_tracker);
+
+// `cfd_to_flush` is the column family whose memtable will be flushed and thus
+// will not depend on any WAL file. nullptr means no memtable is being flushed.
+// The function is only applicable to 2pc mode.
+extern uint64_t FindMinPrepLogReferencedByMemTable(
+    VersionSet* vset, const ColumnFamilyData* cfd_to_flush,
+    const autovector<MemTable*>& memtables_to_flush);
+
 // Fix user-supplied options to be reasonable
 template <class T, class V>
 static void ClipToRange(T* ptr, V minvalue, V maxvalue) {
@@ -24,6 +24,35 @@

 namespace rocksdb {

+bool DBImpl::EnoughRoomForCompaction(
+    const std::vector<CompactionInputFiles>& inputs,
+    bool* sfm_reserved_compact_space, LogBuffer* log_buffer) {
+  // Check if we have enough room to do the compaction
+  bool enough_room = true;
+#ifndef ROCKSDB_LITE
+  auto sfm = static_cast<SstFileManagerImpl*>(
+      immutable_db_options_.sst_file_manager.get());
+  if (sfm) {
+    enough_room = sfm->EnoughRoomForCompaction(inputs);
+    if (enough_room) {
+      *sfm_reserved_compact_space = true;
+    }
+  }
+#else
+  (void)inputs;
+  (void)sfm_reserved_compact_space;
+#endif  // ROCKSDB_LITE
+  if (!enough_room) {
+    // Just in case tests want to change the value of enough_room
+    TEST_SYNC_POINT_CALLBACK(
+        "DBImpl::BackgroundCompaction():CancelledCompaction", &enough_room);
+    ROCKS_LOG_BUFFER(log_buffer,
+                     "Cancelled compaction because not enough room");
+    RecordTick(stats_, COMPACTION_CANCELLED, 1);
+  }
+  return enough_room;
+}
+
 Status DBImpl::SyncClosedLogs(JobContext* job_context) {
  TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Start");
  mutex_.AssertHeld();
@@ -50,6 +79,9 @@ Status DBImpl::SyncClosedLogs(JobContext* job_context) {
                     "[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()) {
+        break;
+      }
    }
    if (s.ok()) {
      s = directories_.GetWalDir()->Fsync();
@@ -95,8 +127,7 @@ Status DBImpl::FlushMemTableToOutputFile(
      dbname_, cfd, immutable_db_options_, mutable_cf_options,
      env_options_for_compaction_, versions_.get(), &mutex_, &shutting_down_,
      snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker,
-      job_context, log_buffer, directories_.GetDbDir(),
-      directories_.GetDataDir(0U),
+      job_context, log_buffer, directories_.GetDbDir(), GetDataDir(cfd, 0U),
      GetCompressionFlush(*cfd->ioptions(), mutable_cf_options), stats_,
      &event_logger_, mutable_cf_options.report_bg_io_stats);

@@ -129,7 +160,7 @@ Status DBImpl::FlushMemTableToOutputFile(
  // and EventListener callback will be called when the db_mutex
  // is unlocked by the current thread.
  if (s.ok()) {
-    s = flush_job.Run(&file_meta);
+    s = flush_job.Run(&logs_with_prep_tracker_, &file_meta);
  } else {
    flush_job.Cancel();
  }
@@ -169,10 +200,10 @@ Status DBImpl::FlushMemTableToOutputFile(
    if (sfm) {
      // Notify sst_file_manager that a new file was added
      std::string file_path = MakeTableFileName(
-          immutable_db_options_.db_paths[0].path, file_meta.fd.GetNumber());
+          cfd->ioptions()->cf_paths[0].path, file_meta.fd.GetNumber());
      sfm->OnAddFile(file_path);
      if (sfm->IsMaxAllowedSpaceReached() && bg_error_.ok()) {
-        Status new_bg_error = Status::IOError("Max allowed space was reached");
+        Status new_bg_error = Status::NoSpace("Max allowed space was reached");
        TEST_SYNC_POINT_CALLBACK(
            "DBImpl::FlushMemTableToOutputFile:MaxAllowedSpaceReached",
            &new_bg_error);
@@ -214,7 +245,7 @@ void DBImpl::NotifyOnFlushBegin(ColumnFamilyData* cfd, FileMetaData* file_meta,
    info.cf_name = cfd->GetName();
    // TODO(yhchiang): make db_paths dynamic in case flush does not
    //                 go to L0 in the future.
-    info.file_path = MakeTableFileName(immutable_db_options_.db_paths[0].path,
+    info.file_path = MakeTableFileName(cfd->ioptions()->cf_paths[0].path,
                                       file_meta->fd.GetNumber());
    info.thread_id = env_->GetThreadID();
    info.job_id = job_id;
@@ -231,6 +262,12 @@ void DBImpl::NotifyOnFlushBegin(ColumnFamilyData* cfd, FileMetaData* file_meta,
  mutex_.Lock();
 // no need to signal bg_cv_ as it will be signaled at the end of the
 // flush process.
+#else
+  (void)cfd;
+  (void)file_meta;
+  (void)mutable_cf_options;
+  (void)job_id;
+  (void)prop;
 #endif  // ROCKSDB_LITE
 }

@@ -259,7 +296,7 @@ void DBImpl::NotifyOnFlushCompleted(ColumnFamilyData* cfd,
    info.cf_name = cfd->GetName();
    // TODO(yhchiang): make db_paths dynamic in case flush does not
    //                 go to L0 in the future.
-    info.file_path = MakeTableFileName(immutable_db_options_.db_paths[0].path,
+    info.file_path = MakeTableFileName(cfd->ioptions()->cf_paths[0].path,
                                       file_meta->fd.GetNumber());
    info.thread_id = env_->GetThreadID();
    info.job_id = job_id;
@@ -276,18 +313,25 @@ void DBImpl::NotifyOnFlushCompleted(ColumnFamilyData* cfd,
  mutex_.Lock();
  // no need to signal bg_cv_ as it will be signaled at the end of the
  // flush process.
+#else
+  (void)cfd;
+  (void)file_meta;
+  (void)mutable_cf_options;
+  (void)job_id;
+  (void)prop;
 #endif  // ROCKSDB_LITE
 }

 Status DBImpl::CompactRange(const CompactRangeOptions& options,
                            ColumnFamilyHandle* column_family,
                            const Slice* begin, const Slice* end) {
-  if (options.target_path_id >= immutable_db_options_.db_paths.size()) {
+  auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
+  auto cfd = cfh->cfd();
+
+  if (options.target_path_id >= cfd->ioptions()->cf_paths.size()) {
    return Status::InvalidArgument("Invalid target path ID");
  }

-  auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
-  auto cfd = cfh->cfd();
  bool exclusive = options.exclusive_manual_compaction;

  bool flush_needed = true;
@@ -384,7 +428,7 @@ Status DBImpl::CompactRange(const CompactRangeOptions& options,
    }
    s = RunManualCompaction(cfd, ColumnFamilyData::kCompactAllLevels,
                            final_output_level, options.target_path_id,
-                            begin, end, exclusive);
+                            options.max_subcompactions, begin, end, exclusive);
  } else {
    for (int level = 0; level <= max_level_with_files; level++) {
      int output_level;
@@ -418,7 +462,7 @@ Status DBImpl::CompactRange(const CompactRangeOptions& options,
        }
      }
      s = RunManualCompaction(cfd, level, output_level, options.target_path_id,
-                              begin, end, exclusive);
+                              options.max_subcompactions, begin, end, exclusive);
      if (!s.ok()) {
        break;
      }
@@ -457,14 +501,19 @@ Status DBImpl::CompactRange(const CompactRangeOptions& options,
  return s;
 }

-Status DBImpl::CompactFiles(
-    const CompactionOptions& compact_options,
-    ColumnFamilyHandle* column_family,
-    const std::vector<std::string>& input_file_names,
-    const int output_level, const int output_path_id,
-    std::vector<std::string>* const output_file_names) {
+Status DBImpl::CompactFiles(const CompactionOptions& compact_options,
+                            ColumnFamilyHandle* column_family,
+                            const std::vector<std::string>& input_file_names,
+                            const int output_level, const int output_path_id,
+                            std::vector<std::string>* const output_file_names) {
 #ifdef ROCKSDB_LITE
-    // not supported in lite version
+  (void)compact_options;
+  (void)column_family;
+  (void)input_file_names;
+  (void)output_level;
+  (void)output_path_id;
+  (void)output_file_names;
+  // not supported in lite version
  return Status::NotSupported("Not supported in ROCKSDB LITE");
 #else
  if (column_family == nullptr) {
@@ -488,9 +537,9 @@ Status DBImpl::CompactFiles(
    // IngestExternalFile() calls to finish.
    WaitForIngestFile();

-    s = CompactFilesImpl(compact_options, cfd, sv->current,
-                         input_file_names, output_file_names, output_level,
-                         output_path_id, &job_context, &log_buffer);
+    s = CompactFilesImpl(compact_options, cfd, sv->current, input_file_names,
+                         output_file_names, output_level, output_path_id,
+                         &job_context, &log_buffer);
  }
  if (sv->Unref()) {
    mutex_.Lock();
@@ -533,9 +582,8 @@ Status DBImpl::CompactFiles(
 Status DBImpl::CompactFilesImpl(
    const CompactionOptions& compact_options, ColumnFamilyData* cfd,
    Version* version, const std::vector<std::string>& input_file_names,
-    std::vector<std::string>* const output_file_names,
-    const int output_level, int output_path_id, JobContext* job_context,
-    LogBuffer* log_buffer) {
+    std::vector<std::string>* const output_file_names, const int output_level,
+    int output_path_id, JobContext* job_context, LogBuffer* log_buffer) {
  mutex_.AssertHeld();

  if (shutting_down_.load(std::memory_order_acquire)) {
@@ -553,7 +601,7 @@ Status DBImpl::CompactFilesImpl(
  version->GetColumnFamilyMetaData(&cf_meta);

  if (output_path_id < 0) {
-    if (immutable_db_options_.db_paths.size() == 1U) {
+    if (cfd->ioptions()->cf_paths.size() == 1U) {
      output_path_id = 0;
    } else {
      return Status::NotSupported(
@@ -582,6 +630,16 @@ Status DBImpl::CompactFilesImpl(
          "files are already being compacted");
    }
  }
+  bool sfm_reserved_compact_space = false;
+  // First check if we have enough room to do the compaction
+  bool enough_room = EnoughRoomForCompaction(
+      input_files, &sfm_reserved_compact_space, log_buffer);
+
+  if (!enough_room) {
+    // m's vars will get set properly at the end of this function,
+    // as long as status == CompactionTooLarge
+    return Status::CompactionTooLarge();
+  }

  // At this point, CompactFiles will be run.
  bg_compaction_scheduled_++;
@@ -615,9 +673,9 @@ Status DBImpl::CompactFilesImpl(
      job_context->job_id, c.get(), immutable_db_options_,
      env_options_for_compaction_, versions_.get(), &shutting_down_,
      preserve_deletes_seqnum_.load(), log_buffer, directories_.GetDbDir(),
-      directories_.GetDataDir(c->output_path_id()), stats_, &mutex_, &bg_error_,
-      snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker,
-      table_cache_, &event_logger_,
+      GetDataDir(c->column_family_data(), c->output_path_id()), stats_, &mutex_,
+      &bg_error_, snapshot_seqs, earliest_write_conflict_snapshot,
+      snapshot_checker, table_cache_, &event_logger_,
      c->mutable_cf_options()->paranoid_file_checks,
      c->mutable_cf_options()->report_bg_io_stats, dbname_,
      nullptr);  // Here we pass a nullptr for CompactionJobStats because
@@ -655,9 +713,17 @@ Status DBImpl::CompactFilesImpl(
  if (status.ok()) {
    InstallSuperVersionAndScheduleWork(
        c->column_family_data(), &job_context->superversion_context,
-       *c->mutable_cf_options());
+        *c->mutable_cf_options(), FlushReason::kManualCompaction);
  }
  c->ReleaseCompactionFiles(s);
+#ifndef ROCKSDB_LITE
+  // Need to make sure SstFileManager does its bookkeeping
+  auto sfm = static_cast<SstFileManagerImpl*>(
+      immutable_db_options_.sst_file_manager.get());
+  if (sfm && sfm_reserved_compact_space) {
+    sfm->OnCompactionCompletion(c.get());
+  }
+#endif  // ROCKSDB_LITE

  ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem);

@@ -684,9 +750,10 @@ Status DBImpl::CompactFilesImpl(

  if (output_file_names != nullptr) {
    for (const auto newf : c->edit()->GetNewFiles()) {
-      (*output_file_names).push_back(TableFileName(
-              immutable_db_options_.db_paths, newf.second.fd.GetNumber(),
-              newf.second.fd.GetPathId()) );
+      (*output_file_names)
+          .push_back(TableFileName(c->immutable_cf_options()->cf_paths,
+                                   newf.second.fd.GetNumber(),
+                                   newf.second.fd.GetPathId()));
    }
  }

@@ -696,6 +763,7 @@ Status DBImpl::CompactFilesImpl(
  if (bg_compaction_scheduled_ == 0) {
    bg_cv_.SignalAll();
  }
+  TEST_SYNC_POINT("CompactFilesImpl:End");

  return status;
 }
@@ -730,9 +798,8 @@ Status DBImpl::ContinueBackgroundWork() {
 }

 void DBImpl::NotifyOnCompactionCompleted(
-    ColumnFamilyData* cfd, Compaction *c, const Status &st,
-    const CompactionJobStats& compaction_job_stats,
-    const int job_id) {
+    ColumnFamilyData* cfd, Compaction* c, const Status& st,
+    const CompactionJobStats& compaction_job_stats, const int job_id) {
 #ifndef ROCKSDB_LITE
  if (immutable_db_options_.listeners.size() == 0U) {
    return;
@@ -760,7 +827,7 @@ void DBImpl::NotifyOnCompactionCompleted(
    info.compression = c->output_compression();
    for (size_t i = 0; i < c->num_input_levels(); ++i) {
      for (const auto fmd : *c->inputs(i)) {
-        auto fn = TableFileName(immutable_db_options_.db_paths,
+        auto fn = TableFileName(c->immutable_cf_options()->cf_paths,
                                fmd->fd.GetNumber(), fmd->fd.GetPathId());
        info.input_files.push_back(fn);
        if (info.table_properties.count(fn) == 0) {
@@ -773,9 +840,9 @@ void DBImpl::NotifyOnCompactionCompleted(
      }
    }
    for (const auto newf : c->edit()->GetNewFiles()) {
-      info.output_files.push_back(TableFileName(immutable_db_options_.db_paths,
-                                                newf.second.fd.GetNumber(),
-                                                newf.second.fd.GetPathId()));
+      info.output_files.push_back(TableFileName(
+          c->immutable_cf_options()->cf_paths, newf.second.fd.GetNumber(),
+          newf.second.fd.GetPathId()));
    }
    for (auto listener : immutable_db_options_.listeners) {
      listener->OnCompactionCompleted(this, info);
@@ -785,6 +852,12 @@ void DBImpl::NotifyOnCompactionCompleted(
  current->Unref();
  // no need to signal bg_cv_ as it will be signaled at the end of the
  // flush process.
+#else
+  (void)cfd;
+  (void)c;
+  (void)st;
+  (void)compaction_job_stats;
+  (void)job_id;
 #endif  // ROCKSDB_LITE
 }

@@ -881,8 +954,9 @@ int DBImpl::MaxMemCompactionLevel(ColumnFamilyHandle* /*column_family*/) {
 int DBImpl::Level0StopWriteTrigger(ColumnFamilyHandle* column_family) {
  auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
  InstrumentedMutexLock l(&mutex_);
-  return cfh->cfd()->GetSuperVersion()->
-      mutable_cf_options.level0_stop_writes_trigger;
+  return cfh->cfd()
+      ->GetSuperVersion()
+      ->mutable_cf_options.level0_stop_writes_trigger;
 }

 Status DBImpl::Flush(const FlushOptions& flush_options,
@@ -891,7 +965,7 @@ Status DBImpl::Flush(const FlushOptions& flush_options,
  ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] Manual flush start.",
                 cfh->GetName().c_str());
  Status s =
-      FlushMemTable(cfh->cfd(), flush_options, FlushReason::kManualCompaction);
+      FlushMemTable(cfh->cfd(), flush_options, FlushReason::kManualFlush);
  ROCKS_LOG_INFO(immutable_db_options_.info_log,
                 "[%s] Manual flush finished, status: %s\n",
                 cfh->GetName().c_str(), s.ToString().c_str());
@@ -900,6 +974,7 @@ Status DBImpl::Flush(const FlushOptions& flush_options,

 Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
                                   int output_level, uint32_t output_path_id,
+                                   uint32_t max_subcompactions,
                                   const Slice* begin, const Slice* end,
                                   bool exclusive, bool disallow_trivial_move) {
  assert(input_level == ColumnFamilyData::kCompactAllLevels ||
@@ -985,11 +1060,12 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
    if (ShouldntRunManualCompaction(&manual) || (manual.in_progress == true) ||
        scheduled ||
        (((manual.manual_end = &manual.tmp_storage1) != nullptr) &&
-             ((compaction = manual.cfd->CompactRange(
-                  *manual.cfd->GetLatestMutableCFOptions(), manual.input_level,
-                  manual.output_level, manual.output_path_id, manual.begin,
-                  manual.end, &manual.manual_end, &manual_conflict)) == nullptr &&
-         manual_conflict))) {
+         ((compaction = manual.cfd->CompactRange(
+               *manual.cfd->GetLatestMutableCFOptions(), manual.input_level,
+               manual.output_level, manual.output_path_id, max_subcompactions,
+               manual.begin, manual.end, &manual.manual_end,
+               &manual_conflict)) == nullptr &&
+          manual_conflict))) {
      // exclusive manual compactions should not see a conflict during
      // CompactRange
      assert(!exclusive || !manual_conflict);
@@ -1122,7 +1198,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
  }
  auto bg_job_limits = GetBGJobLimits();
  bool is_flush_pool_empty =
-    env_->GetBackgroundThreads(Env::Priority::HIGH) == 0;
+      env_->GetBackgroundThreads(Env::Priority::HIGH) == 0;
  while (!is_flush_pool_empty && unscheduled_flushes_ > 0 &&
         bg_flush_scheduled_ < bg_job_limits.max_flushes) {
    unscheduled_flushes_--;
@@ -1198,26 +1274,26 @@ DBImpl::BGJobLimits DBImpl::GetBGJobLimits(int max_background_flushes,
 }

 void DBImpl::AddToCompactionQueue(ColumnFamilyData* cfd) {
-  assert(!cfd->pending_compaction());
+  assert(!cfd->queued_for_compaction());
  cfd->Ref();
  compaction_queue_.push_back(cfd);
-  cfd->set_pending_compaction(true);
+  cfd->set_queued_for_compaction(true);
 }

 ColumnFamilyData* DBImpl::PopFirstFromCompactionQueue() {
  assert(!compaction_queue_.empty());
  auto cfd = *compaction_queue_.begin();
  compaction_queue_.pop_front();
-  assert(cfd->pending_compaction());
-  cfd->set_pending_compaction(false);
+  assert(cfd->queued_for_compaction());
+  cfd->set_queued_for_compaction(false);
  return cfd;
 }

 void DBImpl::AddToFlushQueue(ColumnFamilyData* cfd, FlushReason flush_reason) {
-  assert(!cfd->pending_flush());
+  assert(!cfd->queued_for_flush());
  cfd->Ref();
  flush_queue_.push_back(cfd);
-  cfd->set_pending_flush(true);
+  cfd->set_queued_for_flush(true);
  cfd->SetFlushReason(flush_reason);
 }

@@ -1225,32 +1301,31 @@ ColumnFamilyData* DBImpl::PopFirstFromFlushQueue() {
  assert(!flush_queue_.empty());
  auto cfd = *flush_queue_.begin();
  flush_queue_.pop_front();
-  assert(cfd->pending_flush());
-  cfd->set_pending_flush(false);
+  assert(cfd->queued_for_flush());
+  cfd->set_queued_for_flush(false);
  // TODO: need to unset flush reason?
  return cfd;
 }

 void DBImpl::SchedulePendingFlush(ColumnFamilyData* cfd,
                                  FlushReason flush_reason) {
-  if (!cfd->pending_flush() && cfd->imm()->IsFlushPending()) {
+  if (!cfd->queued_for_flush() && cfd->imm()->IsFlushPending()) {
    AddToFlushQueue(cfd, flush_reason);
    ++unscheduled_flushes_;
  }
 }

 void DBImpl::SchedulePendingCompaction(ColumnFamilyData* cfd) {
-  if (!cfd->pending_compaction() && cfd->NeedsCompaction()) {
+  if (!cfd->queued_for_compaction() && cfd->NeedsCompaction()) {
    AddToCompactionQueue(cfd);
    ++unscheduled_compactions_;
  }
 }

-void DBImpl::SchedulePendingPurge(std::string fname, FileType type,
-                                  uint64_t number, uint32_t path_id,
-                                  int job_id) {
+void DBImpl::SchedulePendingPurge(std::string fname, std::string dir_to_sync,
+                                  FileType type, uint64_t number, int job_id) {
  mutex_.AssertHeld();
-  PurgeFileInfo file_info(fname, type, number, path_id, job_id);
+  PurgeFileInfo file_info(fname, dir_to_sync, type, number, job_id);
  purge_queue_.push_back(std::move(file_info));
 }

@@ -1379,7 +1454,7 @@ void DBImpl::BackgroundCallFlush() {
      // chew up resources for failed flushes for the duration of
      // the problem.
      uint64_t error_cnt =
-        default_cf_internal_stats_->BumpAndGetBackgroundErrorCount();
+          default_cf_internal_stats_->BumpAndGetBackgroundErrorCount();
      bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
      mutex_.Unlock();
      ROCKS_LOG_ERROR(immutable_db_options_.info_log,
@@ -1479,6 +1554,7 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
    // have created (they might not be all recorded in job_context in case of a
    // failure). Thus, we force full scan in FindObsoleteFiles()
    FindObsoleteFiles(&job_context, !s.ok() && !s.IsShutdownInProgress());
+    TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:FoundObsoleteFiles");

    // delete unnecessary files if any, this is done outside the mutex
    if (job_context.HaveSomethingToClean() ||
@@ -1492,6 +1568,7 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
      log_buffer.FlushBufferToLog();
      if (job_context.HaveSomethingToDelete()) {
        PurgeObsoleteFiles(job_context);
+        TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles");
      }
      job_context.Clean();
      mutex_.Lock();
@@ -1576,9 +1653,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,

  // InternalKey manual_end_storage;
  // InternalKey* manual_end = &manual_end_storage;
-#ifndef ROCKSDB_LITE
-  bool sfm_bookkeeping = false;
-#endif  // ROCKSDB_LITE
+  bool sfm_reserved_compact_space = false;
  if (is_manual) {
    ManualCompactionState* m = manual_compaction;
    assert(m->in_progress);
@@ -1592,16 +1667,29 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                       (m->begin ? m->begin->DebugString().c_str() : "(begin)"),
                       (m->end ? m->end->DebugString().c_str() : "(end)"));
    } else {
-      ROCKS_LOG_BUFFER(
-          log_buffer,
-          "[%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->done || m->manual_end == nullptr)
-               ? "(end)"
-               : m->manual_end->DebugString().c_str()));
+      // First check if we have enough room to do the compaction
+      bool enough_room = EnoughRoomForCompaction(
+          *(c->inputs()), &sfm_reserved_compact_space, log_buffer);
+
+      if (!enough_room) {
+        // Then don't do the compaction
+        c->ReleaseCompactionFiles(status);
+        c.reset();
+        // m's vars will get set properly at the end of this function,
+        // as long as status == CompactionTooLarge
+        status = Status::CompactionTooLarge();
+      } else {
+        ROCKS_LOG_BUFFER(
+            log_buffer,
+            "[%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->done || m->manual_end == nullptr)
+                 ? "(end)"
+                 : m->manual_end->DebugString().c_str()));
+      }
    }
  } else if (!is_prepicked && !compaction_queue_.empty()) {
    if (HasExclusiveManualCompaction()) {
@@ -1642,24 +1730,10 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
      c.reset(cfd->PickCompaction(*mutable_cf_options, log_buffer));
      TEST_SYNC_POINT("DBImpl::BackgroundCompaction():AfterPickCompaction");

-      bool enough_room = true;
      if (c != nullptr) {
-#ifndef ROCKSDB_LITE
-        auto sfm = static_cast<SstFileManagerImpl*>(
-            immutable_db_options_.sst_file_manager.get());
-        if (sfm) {
-          enough_room = sfm->EnoughRoomForCompaction(c.get());
-          if (enough_room) {
-            sfm_bookkeeping = true;
-          }
-        }
-#endif  // ROCKSDB_LITE
-        if (!enough_room) {
-          // Just in case tests want to change the value of enough_room
-          TEST_SYNC_POINT_CALLBACK(
-              "DBImpl::BackgroundCompaction():CancelledCompaction",
-              &enough_room);
-        }
+        bool enough_room = EnoughRoomForCompaction(
+            *(c->inputs()), &sfm_reserved_compact_space, log_buffer);
+
        if (!enough_room) {
          // Then don't do the compaction
          c->ReleaseCompactionFiles(status);
@@ -1668,9 +1742,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
              ->storage_info()
              ->ComputeCompactionScore(*(c->immutable_cf_options()),
                                       *(c->mutable_cf_options()));
-
-          ROCKS_LOG_BUFFER(log_buffer,
-                           "Cancelled compaction because not enough room");
          AddToCompactionQueue(cfd);
          ++unscheduled_compactions_;

@@ -1678,7 +1749,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
          // Don't need to sleep here, because BackgroundCallCompaction
          // will sleep if !s.ok()
          status = Status::CompactionTooLarge();
-          RecordTick(stats_, COMPACTION_CANCELLED, 1);
        } else {
          // update statistics
          MeasureTime(stats_, NUM_FILES_IN_SINGLE_COMPACTION,
@@ -1727,7 +1797,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                                    &mutex_, directories_.GetDbDir());
    InstallSuperVersionAndScheduleWork(
        c->column_family_data(), &job_context->superversion_context,
-        *c->mutable_cf_options());
+        *c->mutable_cf_options(), FlushReason::kAutoCompaction);
    ROCKS_LOG_BUFFER(log_buffer, "[%s] Deleted %d files\n",
                     c->column_family_data()->GetName().c_str(),
                     c->num_input_files(0));
@@ -1758,11 +1828,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                           f->largest, f->smallest_seqno, f->largest_seqno,
                           f->marked_for_compaction);

-        ROCKS_LOG_BUFFER(log_buffer, "[%s] Moving #%" PRIu64
-                                     " to level-%d %" PRIu64 " bytes\n",
-                         c->column_family_data()->GetName().c_str(),
-                         f->fd.GetNumber(), c->output_level(),
-                         f->fd.GetFileSize());
+        ROCKS_LOG_BUFFER(
+            log_buffer,
+            "[%s] Moving #%" PRIu64 " to level-%d %" PRIu64 " bytes\n",
+            c->column_family_data()->GetName().c_str(), f->fd.GetNumber(),
+            c->output_level(), f->fd.GetFileSize());
        ++moved_files;
        moved_bytes += f->fd.GetFileSize();
      }
@@ -1774,7 +1844,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    // Use latest MutableCFOptions
    InstallSuperVersionAndScheduleWork(
        c->column_family_data(), &job_context->superversion_context,
-        *c->mutable_cf_options());
+        *c->mutable_cf_options(), FlushReason::kAutoCompaction);

    VersionStorageInfo::LevelSummaryStorage tmp;
    c->column_family_data()->internal_stats()->IncBytesMoved(c->output_level(),
@@ -1796,9 +1866,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,

    // Clear Instrument
    ThreadStatusUtil::ResetThreadStatus();
-  } else if (c->column_family_data()->ioptions()->compaction_style ==
-                 kCompactionStyleUniversal &&
-             !is_prepicked && c->output_level() > 0 &&
+  } else if (!is_prepicked && c->output_level() > 0 &&
             c->output_level() ==
                 c->column_family_data()
                     ->current()
@@ -1806,9 +1874,9 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                     ->MaxOutputLevel(
                         immutable_db_options_.allow_ingest_behind) &&
             env_->GetBackgroundThreads(Env::Priority::BOTTOM) > 0) {
-    // Forward universal compactions involving last level to the bottom pool
-    // if it exists, such that long-running compactions can't block short-
-    // lived ones, like L0->L0s.
+    // Forward compactions involving last level to the bottom pool if it exists,
+    // such that compactions unlikely to contribute to write stalls can be
+    // delayed or deprioritized.
    TEST_SYNC_POINT("DBImpl::BackgroundCompaction:ForwardToBottomPriPool");
    CompactionArg* ca = new CompactionArg;
    ca->db = this;
@@ -1819,7 +1887,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca, Env::Priority::BOTTOM,
                   this, &DBImpl::UnscheduleCallback);
  } else {
-    int output_level  __attribute__((__unused__));
+    int output_level __attribute__((__unused__));
    output_level = c->output_level();
    TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:NonTrivial",
                             &output_level);
@@ -1836,8 +1904,8 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
        job_context->job_id, c.get(), immutable_db_options_,
        env_options_for_compaction_, versions_.get(), &shutting_down_,
        preserve_deletes_seqnum_.load(), log_buffer, directories_.GetDbDir(),
-        directories_.GetDataDir(c->output_path_id()), stats_, &mutex_,
-        &bg_error_, snapshot_seqs, earliest_write_conflict_snapshot,
+        GetDataDir(c->column_family_data(), c->output_path_id()), stats_,
+        &mutex_, &bg_error_, snapshot_seqs, earliest_write_conflict_snapshot,
        snapshot_checker, table_cache_, &event_logger_,
        c->mutable_cf_options()->paranoid_file_checks,
        c->mutable_cf_options()->report_bg_io_stats, dbname_,
@@ -1853,7 +1921,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    if (status.ok()) {
      InstallSuperVersionAndScheduleWork(
          c->column_family_data(), &job_context->superversion_context,
-          *c->mutable_cf_options());
+          *c->mutable_cf_options(), FlushReason::kAutoCompaction);
    }
    *made_progress = true;
  }
@@ -1865,14 +1933,13 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    // Need to make sure SstFileManager does its bookkeeping
    auto sfm = static_cast<SstFileManagerImpl*>(
        immutable_db_options_.sst_file_manager.get());
-    if (sfm && sfm_bookkeeping) {
+    if (sfm && sfm_reserved_compact_space) {
      sfm->OnCompactionCompletion(c.get());
    }
 #endif  // ROCKSDB_LITE

-    NotifyOnCompactionCompleted(
-        c->column_family_data(), c.get(), status,
-        compaction_job_stats, job_context->job_id);
+    NotifyOnCompactionCompleted(c->column_family_data(), c.get(), status,
+                                compaction_job_stats, job_context->job_id);
  }
  // this will unref its input_version and column_family_data
  c.reset();
@@ -1930,7 +1997,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
      m->begin = &m->tmp_storage;
      m->incomplete = true;
    }
-    m->in_progress = false; // not being processed anymore
+    m->in_progress = false;  // not being processed anymore
  }
  TEST_SYNC_POINT("DBImpl::BackgroundCompaction:Finish");
  return status;
@@ -2030,8 +2097,7 @@ bool DBImpl::MCOverlap(ManualCompactionState* m, ManualCompactionState* m1) {
 }

 // SuperVersionContext gets created and destructed outside of the lock --
-// we
-// use this convinently to:
+// we use this conveniently to:
 // * malloc one SuperVersion() outside of the lock -- new_superversion
 // * delete SuperVersion()s outside of the lock -- superversions_to_free
 //
@@ -2044,7 +2110,7 @@ bool DBImpl::MCOverlap(ManualCompactionState* m, ManualCompactionState* m1) {

 void DBImpl::InstallSuperVersionAndScheduleWork(
    ColumnFamilyData* cfd, SuperVersionContext* sv_context,
-    const MutableCFOptions& mutable_cf_options) {
+    const MutableCFOptions& mutable_cf_options, FlushReason flush_reason) {
  mutex_.AssertHeld();

  // Update max_total_in_memory_state_
@@ -2058,20 +2124,49 @@ void DBImpl::InstallSuperVersionAndScheduleWork(
  if (sv_context->new_superversion == nullptr) {
    sv_context->NewSuperVersion();
  }
-  cfd->InstallSuperVersion(sv_context, &mutex_,
-                           mutable_cf_options);
+  cfd->InstallSuperVersion(sv_context, &mutex_, mutable_cf_options);

  // Whenever we install new SuperVersion, we might need to issue new flushes or
  // compactions.
-  SchedulePendingFlush(cfd, FlushReason::kSuperVersionChange);
+  SchedulePendingFlush(cfd, flush_reason);
  SchedulePendingCompaction(cfd);
  MaybeScheduleFlushOrCompaction();

  // Update max_total_in_memory_state_
-  max_total_in_memory_state_ =
-      max_total_in_memory_state_ - old_memtable_size +
-      mutable_cf_options.write_buffer_size *
-      mutable_cf_options.max_write_buffer_number;
+  max_total_in_memory_state_ = max_total_in_memory_state_ - old_memtable_size +
+                               mutable_cf_options.write_buffer_size *
+                                   mutable_cf_options.max_write_buffer_number;
+}
+
+// ShouldPurge is called by FindObsoleteFiles when doing a full scan,
+// and db mutex (mutex_) should already be held. This function performs a
+// linear scan of an vector (files_grabbed_for_purge_) in search of a
+// certain element. We expect FindObsoleteFiles with full scan to occur once
+// every 10 hours by default, and the size of the vector is small.
+// Therefore, the cost is affordable even if the mutex is held.
+// Actually, the current implementation of FindObsoleteFiles with
+// full_scan=true can issue I/O requests to obtain list of files in
+// directories, e.g. env_->getChildren while holding db mutex.
+// In the future, if we want to reduce the cost of search, we may try to keep
+// the vector sorted.
+bool DBImpl::ShouldPurge(uint64_t file_number) const {
+  for (auto fn : files_grabbed_for_purge_) {
+    if (file_number == fn) {
+      return false;
+    }
+  }
+  for (const auto& purge_file_info : purge_queue_) {
+    if (purge_file_info.number == file_number) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// MarkAsGrabbedForPurge is called by FindObsoleteFiles, and db mutex
+// (mutex_) should already be held.
+void DBImpl::MarkAsGrabbedForPurge(uint64_t file_number) {
+  files_grabbed_for_purge_.emplace_back(file_number);
 }

 void DBImpl::SetSnapshotChecker(SnapshotChecker* snapshot_checker) {
@@ -25,6 +25,12 @@ void DBImpl::TEST_SwitchWAL() {
  SwitchWAL(&write_context);
 }

+bool DBImpl::TEST_WALBufferIsEmpty() {
+  InstrumentedMutexLock wl(&log_write_mutex_);
+  log::Writer* cur_log_writer = logs_.back().writer;
+  return cur_log_writer->TEST_BufferIsEmpty();
+}
+
 int64_t DBImpl::TEST_MaxNextLevelOverlappingBytes(
    ColumnFamilyHandle* column_family) {
  ColumnFamilyData* cfd;
@@ -80,7 +86,7 @@ Status DBImpl::TEST_CompactRange(int level, const Slice* begin,
       cfd->ioptions()->compaction_style == kCompactionStyleFIFO)
          ? level
          : level + 1;
-  return RunManualCompaction(cfd, level, output_level, 0, begin, end, true,
+  return RunManualCompaction(cfd, level, output_level, 0, 0, begin, end, true,
                             disallow_trivial_move);
 }

@@ -184,17 +190,21 @@ Status DBImpl::TEST_GetAllImmutableCFOptions(
 }

 uint64_t DBImpl::TEST_FindMinLogContainingOutstandingPrep() {
-  return FindMinLogContainingOutstandingPrep();
+  return logs_with_prep_tracker_.FindMinLogContainingOutstandingPrep();
 }

 size_t DBImpl::TEST_PreparedSectionCompletedSize() {
-  return prepared_section_completed_.size();
+  return logs_with_prep_tracker_.TEST_PreparedSectionCompletedSize();
 }

-size_t DBImpl::TEST_LogsWithPrepSize() { return logs_with_prep_.size(); }
+size_t DBImpl::TEST_LogsWithPrepSize() {
+  return logs_with_prep_tracker_.TEST_LogsWithPrepSize();
+}

 uint64_t DBImpl::TEST_FindMinPrepLogReferencedByMemTable() {
-  return FindMinPrepLogReferencedByMemTable();
+  autovector<MemTable*> empty_list;
+  return FindMinPrepLogReferencedByMemTable(versions_.get(), nullptr,
+                                            empty_list);
 }

 Status DBImpl::TEST_GetLatestMutableCFOptions(
@@ -12,125 +12,19 @@
 #define __STDC_FORMAT_MACROS
 #endif
 #include <inttypes.h>
+#include <unordered_set>
 #include "db/event_helpers.h"
+#include "db/memtable_list.h"
 #include "util/file_util.h"
 #include "util/sst_file_manager_impl.h"

-
 namespace rocksdb {
-uint64_t DBImpl::FindMinPrepLogReferencedByMemTable() {
-  if (!allow_2pc()) {
-    return 0;
-  }
-
-  uint64_t min_log = 0;
-
-  // we must look through the memtables for two phase transactions
-  // that have been committed but not yet flushed
-  for (auto loop_cfd : *versions_->GetColumnFamilySet()) {
-    if (loop_cfd->IsDropped()) {
-      continue;
-    }
-
-    auto log = loop_cfd->imm()->GetMinLogContainingPrepSection();
-
-    if (log > 0 && (min_log == 0 || log < min_log)) {
-      min_log = log;
-    }
-
-    log = loop_cfd->mem()->GetMinLogContainingPrepSection();
-
-    if (log > 0 && (min_log == 0 || log < min_log)) {
-      min_log = log;
-    }
-  }
-
-  return min_log;
-}
-
-void DBImpl::MarkLogAsHavingPrepSectionFlushed(uint64_t log) {
-  assert(log != 0);
-  std::lock_guard<std::mutex> lock(prepared_section_completed_mutex_);
-  auto it = prepared_section_completed_.find(log);
-  if (UNLIKELY(it == prepared_section_completed_.end())) {
-    prepared_section_completed_[log] = 1;
-  } else {
-    it->second += 1;
-  }
-}
-
-void DBImpl::MarkLogAsContainingPrepSection(uint64_t log) {
-  assert(log != 0);
-  std::lock_guard<std::mutex> lock(logs_with_prep_mutex_);
-
-  auto rit = logs_with_prep_.rbegin();
-  bool updated = false;
-  // Most probably the last log is the one that is being marked for
-  // having a prepare section; so search from the end.
-  for (; rit != logs_with_prep_.rend() && rit->log >= log; ++rit) {
-    if (rit->log == log) {
-      rit->cnt++;
-      updated = true;
-      break;
-    }
-  }
-  if (!updated) {
-    // We are either at the start, or at a position with rit->log < log
-    logs_with_prep_.insert(rit.base(), {log, 1});
-  }
-}
-
-uint64_t DBImpl::FindMinLogContainingOutstandingPrep() {
-  std::lock_guard<std::mutex> lock(logs_with_prep_mutex_);
-  auto it = logs_with_prep_.begin();
-  // start with the smallest log
-  for (; it != logs_with_prep_.end();) {
-    auto min_log = it->log;
-    {
-      std::lock_guard<std::mutex> lock2(prepared_section_completed_mutex_);
-      auto completed_it = prepared_section_completed_.find(min_log);
-      if (completed_it == prepared_section_completed_.end() ||
-          completed_it->second < it->cnt) {
-        return min_log;
-      }
-      assert(completed_it != prepared_section_completed_.end() &&
-             completed_it->second == it->cnt);
-      prepared_section_completed_.erase(completed_it);
-    }
-    // erase from beginning in vector is not efficient but this function is not
-    // on the fast path.
-    it = logs_with_prep_.erase(it);
-  }
-  // no such log found
-  return 0;
-}
-
 uint64_t DBImpl::MinLogNumberToKeep() {
-  uint64_t log_number = versions_->MinLogNumber();
-
  if (allow_2pc()) {
-    // if are 2pc we must consider logs containing prepared
-    // sections of outstanding transactions.
-    //
-    // We must check min logs with outstanding prep before we check
-    // logs references by memtables because a log referenced by the
-    // first data structure could transition to the second under us.
-    //
-    // TODO(horuff): iterating over all column families under db mutex.
-    // should find more optimal solution
-    auto min_log_in_prep_heap = FindMinLogContainingOutstandingPrep();
-
-    if (min_log_in_prep_heap != 0 && min_log_in_prep_heap < log_number) {
-      log_number = min_log_in_prep_heap;
-    }
-
-    auto min_log_refed_by_mem = FindMinPrepLogReferencedByMemTable();
-
-    if (min_log_refed_by_mem != 0 && min_log_refed_by_mem < log_number) {
-      log_number = min_log_refed_by_mem;
-    }
+    return versions_->min_log_number_to_keep_2pc();
+  } else {
+    return versions_->MinLogNumberWithUnflushedData();
  }
-  return log_number;
 }

 // * Returns the list of live files in 'sst_live'
@@ -187,27 +81,65 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
                              &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.
+  for (const auto& sst_to_del : job_context->sst_delete_files) {
+    MarkAsGrabbedForPurge(sst_to_del.metadata->fd.GetNumber());
+  }
+
  // store the current filenum, lognum, etc
  job_context->manifest_file_number = versions_->manifest_file_number();
  job_context->pending_manifest_file_number =
      versions_->pending_manifest_file_number();
  job_context->log_number = MinLogNumberToKeep();
-
  job_context->prev_log_number = versions_->prev_log_number();

  versions_->AddLiveFiles(&job_context->sst_live);
  if (doing_the_full_scan) {
+    InfoLogPrefix info_log_prefix(!immutable_db_options_.db_log_dir.empty(),
+        dbname_);
+    std::vector<std::string> paths;
    for (size_t path_id = 0; path_id < immutable_db_options_.db_paths.size();
         path_id++) {
+      paths.emplace_back(immutable_db_options_.db_paths[path_id].path);
+    }
+
+    // Note that if cf_paths is not specified in the ColumnFamilyOptions
+    // of a particular column family, we use db_paths as the cf_paths
+    // setting. Hence, there can be multiple duplicates of files from db_paths
+    // in the following code. The duplicate are removed while identifying
+    // unique files in PurgeObsoleteFiles.
+    for (auto cfd : *versions_->GetColumnFamilySet()) {
+      for (size_t path_id = 0; path_id < cfd->ioptions()->cf_paths.size();
+           path_id++) {
+        paths.emplace_back(cfd->ioptions()->cf_paths[path_id].path);
+      }
+    }
+
+    for (auto& path : paths) {
      // set of all files in the directory. We'll exclude files that are still
      // alive in the subsequent processings.
      std::vector<std::string> files;
-      env_->GetChildren(immutable_db_options_.db_paths[path_id].path,
-                        &files);  // Ignore errors
-      for (std::string file : files) {
+      env_->GetChildren(path, &files);  // Ignore errors
+      for (const std::string& file : files) {
+        uint64_t number;
+        FileType type;
+        // 1. If we cannot parse the file name, we skip;
+        // 2. If the file with file_number equals number has already been
+        // grabbed for purge by another compaction job, or it has already been
+        // schedule for purge, we also skip it if we
+        // are doing full scan in order to avoid double deletion of the same
+        // file under race conditions. See
+        // https://github.com/facebook/rocksdb/issues/3573
+        if (!ParseFileName(file, &number, info_log_prefix.prefix, &type) ||
+            !ShouldPurge(number)) {
+          continue;
+        }
+
        // TODO(icanadi) clean up this mess to avoid having one-off "/" prefixes
        job_context->full_scan_candidate_files.emplace_back(
-            "/" + file, static_cast<uint32_t>(path_id));
+            "/" + file, path);
      }
    }

@@ -216,8 +148,9 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
      std::vector<std::string> log_files;
      env_->GetChildren(immutable_db_options_.wal_dir,
                        &log_files);  // Ignore errors
-      for (std::string log_file : log_files) {
-        job_context->full_scan_candidate_files.emplace_back(log_file, 0);
+      for (const std::string& log_file : log_files) {
+        job_context->full_scan_candidate_files.emplace_back(log_file,
+            immutable_db_options_.wal_dir);
      }
    }
    // Add info log files in db_log_dir
@@ -226,8 +159,9 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
      std::vector<std::string> info_log_files;
      // Ignore errors
      env_->GetChildren(immutable_db_options_.db_log_dir, &info_log_files);
-      for (std::string log_file : info_log_files) {
-        job_context->full_scan_candidate_files.emplace_back(log_file, 0);
+      for (std::string& log_file : info_log_files) {
+        job_context->full_scan_candidate_files.emplace_back(log_file,
+            immutable_db_options_.db_log_dir);
      }
    }
  }
@@ -302,22 +236,24 @@ bool CompareCandidateFile(const JobContext::CandidateFileInfo& first,
  } else if (first.file_name < second.file_name) {
    return false;
  } else {
-    return (first.path_id > second.path_id);
+    return (first.file_path > second.file_path);
  }
 }
 };  // namespace

 // Delete obsolete files and log status and information of file deletion
 void DBImpl::DeleteObsoleteFileImpl(int job_id, const std::string& fname,
-                                    FileType type, uint64_t number,
-                                    uint32_t path_id) {
+                                    const std::string& path_to_sync,
+                                    FileType type, uint64_t number) {
  Status file_deletion_status;
  if (type == kTableFile) {
    file_deletion_status =
-        DeleteSSTFile(&immutable_db_options_, fname, path_id);
+        DeleteSSTFile(&immutable_db_options_, fname, path_to_sync);
  } else {
    file_deletion_status = env_->DeleteFile(fname);
  }
+  TEST_SYNC_POINT_CALLBACK("DBImpl::DeleteObsoleteFileImpl:AfterDeletion",
+      &file_deletion_status);
  if (file_deletion_status.ok()) {
    ROCKS_LOG_DEBUG(immutable_db_options_.info_log,
                    "[JOB %d] Delete %s type=%d #%" PRIu64 " -- %s\n", job_id,
@@ -347,7 +283,7 @@ void DBImpl::DeleteObsoleteFileImpl(int job_id, const std::string& fname,
 // belong to live files are possibly removed. Also, removes all the
 // files in sst_delete_files and log_delete_files.
 // It is not necessary to hold the mutex when invoking this method.
-void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
+void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
  TEST_SYNC_POINT("DBImpl::PurgeObsoleteFiles:Begin");
  // we'd better have sth to delete
  assert(state.HaveSomethingToDelete());
@@ -370,23 +306,23 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
      state.log_delete_files.size() + state.manifest_delete_files.size());
  // We may ignore the dbname when generating the file names.
  const char* kDumbDbName = "";
-  for (auto file : state.sst_delete_files) {
+  for (auto& file : state.sst_delete_files) {
    candidate_files.emplace_back(
-        MakeTableFileName(kDumbDbName, file->fd.GetNumber()),
-        file->fd.GetPathId());
-    if (file->table_reader_handle) {
-      table_cache_->Release(file->table_reader_handle);
+        MakeTableFileName(kDumbDbName, file.metadata->fd.GetNumber()), file.path);
+    if (file.metadata->table_reader_handle) {
+      table_cache_->Release(file.metadata->table_reader_handle);
    }
-    delete file;
+    file.DeleteMetadata();
  }

  for (auto file_num : state.log_delete_files) {
    if (file_num > 0) {
-      candidate_files.emplace_back(LogFileName(kDumbDbName, file_num), 0);
+      candidate_files.emplace_back(LogFileName(kDumbDbName, file_num),
+          immutable_db_options_.wal_dir);
    }
  }
  for (const auto& filename : state.manifest_delete_files) {
-    candidate_files.emplace_back(filename, 0);
+    candidate_files.emplace_back(filename, dbname_);
  }

  // dedup state.candidate_files so we don't try to delete the same
@@ -409,9 +345,9 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
  std::vector<std::string> old_info_log_files;
  InfoLogPrefix info_log_prefix(!immutable_db_options_.db_log_dir.empty(),
                                dbname_);
+  std::unordered_set<uint64_t> files_to_del;
  for (const auto& candidate_file : candidate_files) {
    std::string to_delete = candidate_file.file_name;
-    uint32_t path_id = candidate_file.path_id;
    uint64_t number;
    FileType type;
    // Ignore file if we cannot recognize it.
@@ -437,6 +373,9 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
        // DontDeletePendingOutputs fail
        keep = (sst_live_map.find(number) != sst_live_map.end()) ||
               number >= state.min_pending_output;
+        if (!keep) {
+          files_to_del.insert(number);
+        }
        break;
      case kTempFile:
        // Any temp files that are currently being written to must
@@ -472,13 +411,16 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
    }

    std::string fname;
+    std::string dir_to_sync;
    if (type == kTableFile) {
      // evict from cache
      TableCache::Evict(table_cache_.get(), number);
-      fname = TableFileName(immutable_db_options_.db_paths, number, path_id);
+      fname = MakeTableFileName(candidate_file.file_path, number);
+      dir_to_sync = candidate_file.file_path;
    } else {
-      fname = ((type == kLogFile) ? immutable_db_options_.wal_dir : dbname_) +
-              "/" + to_delete;
+      dir_to_sync =
+          (type == kLogFile) ? immutable_db_options_.wal_dir : dbname_;
+      fname = dir_to_sync + "/" + to_delete;
    }

 #ifndef ROCKSDB_LITE
@@ -492,12 +434,25 @@ void DBImpl::PurgeObsoleteFiles(const JobContext& state, bool schedule_only) {
    Status file_deletion_status;
    if (schedule_only) {
      InstrumentedMutexLock guard_lock(&mutex_);
-      SchedulePendingPurge(fname, type, number, path_id, state.job_id);
+      SchedulePendingPurge(fname, dir_to_sync, type, number, state.job_id);
    } else {
-      DeleteObsoleteFileImpl(state.job_id, fname, type, number, path_id);
+      DeleteObsoleteFileImpl(state.job_id, fname, dir_to_sync, type, number);
    }
  }

+  {
+    // After purging obsolete files, remove them from files_grabbed_for_purge_.
+    // Use a temporary vector to perform bulk deletion via swap.
+    InstrumentedMutexLock guard_lock(&mutex_);
+    std::vector<uint64_t> tmp;
+    for (auto fn : files_grabbed_for_purge_) {
+      if (files_to_del.count(fn) == 0) {
+        tmp.emplace_back(fn);
+      }
+    }
+    files_grabbed_for_purge_.swap(tmp);
+  }
+
  // Delete old info log files.
  size_t old_info_log_file_count = old_info_log_files.size();
  if (old_info_log_file_count != 0 &&
@@ -557,4 +512,95 @@ void DBImpl::DeleteObsoleteFiles() {
  job_context.Clean();
  mutex_.Lock();
 }
+
+uint64_t FindMinPrepLogReferencedByMemTable(
+    VersionSet* vset, const ColumnFamilyData* cfd_to_flush,
+    const autovector<MemTable*>& memtables_to_flush) {
+  uint64_t min_log = 0;
+
+  // we must look through the memtables for two phase transactions
+  // that have been committed but not yet flushed
+  for (auto loop_cfd : *vset->GetColumnFamilySet()) {
+    if (loop_cfd->IsDropped() || loop_cfd == cfd_to_flush) {
+      continue;
+    }
+
+    auto log = loop_cfd->imm()->PrecomputeMinLogContainingPrepSection(
+        memtables_to_flush);
+
+    if (log > 0 && (min_log == 0 || log < min_log)) {
+      min_log = log;
+    }
+
+    log = loop_cfd->mem()->GetMinLogContainingPrepSection();
+
+    if (log > 0 && (min_log == 0 || log < min_log)) {
+      min_log = log;
+    }
+  }
+
+  return min_log;
+}
+
+uint64_t PrecomputeMinLogNumberToKeep(
+    VersionSet* vset, const ColumnFamilyData& cfd_to_flush,
+    autovector<VersionEdit*> edit_list,
+    const autovector<MemTable*>& memtables_to_flush,
+    LogsWithPrepTracker* prep_tracker) {
+  assert(vset != nullptr);
+  assert(prep_tracker != nullptr);
+  // Calculate updated min_log_number_to_keep
+  // Since the function should only be called in 2pc mode, log number in
+  // the version edit should be sufficient.
+
+  // Precompute the min log number containing unflushed data for the column
+  // family being flushed (`cfd_to_flush`).
+  uint64_t cf_min_log_number_to_keep = 0;
+  for (auto& e : edit_list) {
+    if (e->has_log_number()) {
+      cf_min_log_number_to_keep =
+          std::max(cf_min_log_number_to_keep, e->log_number());
+    }
+  }
+  if (cf_min_log_number_to_keep == 0) {
+    // No version edit contains information on log number. The log number
+    // for this column family should stay the same as it is.
+    cf_min_log_number_to_keep = cfd_to_flush.GetLogNumber();
+  }
+
+  // Get min log number containing unflushed data for other column families.
+  uint64_t min_log_number_to_keep =
+      vset->PreComputeMinLogNumberWithUnflushedData(&cfd_to_flush);
+  if (cf_min_log_number_to_keep != 0) {
+    min_log_number_to_keep =
+        std::min(cf_min_log_number_to_keep, min_log_number_to_keep);
+  }
+
+  // if are 2pc we must consider logs containing prepared
+  // sections of outstanding transactions.
+  //
+  // We must check min logs with outstanding prep before we check
+  // logs references by memtables because a log referenced by the
+  // first data structure could transition to the second under us.
+  //
+  // TODO: iterating over all column families under db mutex.
+  // should find more optimal solution
+  auto min_log_in_prep_heap =
+      prep_tracker->FindMinLogContainingOutstandingPrep();
+
+  if (min_log_in_prep_heap != 0 &&
+      min_log_in_prep_heap < min_log_number_to_keep) {
+    min_log_number_to_keep = min_log_in_prep_heap;
+  }
+
+  uint64_t min_log_refed_by_mem = FindMinPrepLogReferencedByMemTable(
+      vset, &cfd_to_flush, memtables_to_flush);
+
+  if (min_log_refed_by_mem != 0 &&
+      min_log_refed_by_mem < min_log_number_to_keep) {
+    min_log_number_to_keep = min_log_refed_by_mem;
+  }
+  return min_log_number_to_keep;
+}
+
 }  // namespace rocksdb
@@ -106,14 +106,14 @@ DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
    result.db_paths.emplace_back(dbname, std::numeric_limits<uint64_t>::max());
  }

-  if (result.use_direct_io_for_flush_and_compaction &&
+  if (result.use_direct_reads &&
      result.compaction_readahead_size == 0) {
    TEST_SYNC_POINT_CALLBACK("SanitizeOptions:direct_io", nullptr);
    result.compaction_readahead_size = 1024 * 1024 * 2;
  }

  if (result.compaction_readahead_size > 0 ||
-      result.use_direct_io_for_flush_and_compaction) {
+      result.use_direct_reads) {
    result.new_table_reader_for_compaction_inputs = true;
  }

@@ -163,28 +163,23 @@ static Status ValidateOptions(
    if (s.ok() && db_options.allow_concurrent_memtable_write) {
      s = CheckConcurrentWritesSupported(cfd.options);
    }
+    if (s.ok()) {
+      s = CheckCFPathsSupported(db_options, cfd.options);
+    }
    if (!s.ok()) {
      return s;
    }
-    if (db_options.db_paths.size() > 1) {
-      if ((cfd.options.compaction_style != kCompactionStyleUniversal) &&
-          (cfd.options.compaction_style != kCompactionStyleLevel)) {
-        return Status::NotSupported(
-            "More than one DB paths are only supported in "
-            "universal and level compaction styles. ");
-      }
-    }
-    if (cfd.options.compaction_options_fifo.ttl > 0) {
+
+    if (cfd.options.ttl > 0 || cfd.options.compaction_options_fifo.ttl > 0) {
      if (db_options.max_open_files != -1) {
        return Status::NotSupported(
-            "FIFO Compaction with TTL is only supported when files are always "
+            "TTL is only supported when files are always "
            "kept open (set max_open_files = -1). ");
      }
      if (cfd.options.table_factory->Name() !=
          BlockBasedTableFactory().Name()) {
        return Status::NotSupported(
-            "FIFO Compaction with TTL is only supported in "
-            "Block-Based Table format. ");
+            "TTL is only supported in Block-Based Table format. ");
      }
    }
  }
@@ -254,9 +249,9 @@ Status DBImpl::NewDB() {
  return s;
 }

-Status DBImpl::Directories::CreateAndNewDirectory(
+Status DBImpl::CreateAndNewDirectory(
    Env* env, const std::string& dirname,
-    std::unique_ptr<Directory>* directory) const {
+    std::unique_ptr<Directory>* directory) {
  // We call CreateDirIfMissing() as the directory may already exist (if we
  // are reopening a DB), when this happens we don't want creating the
  // directory to cause an error. However, we need to check if creating the
@@ -274,12 +269,12 @@ Status DBImpl::Directories::CreateAndNewDirectory(
 Status DBImpl::Directories::SetDirectories(
    Env* env, const std::string& dbname, const std::string& wal_dir,
    const std::vector<DbPath>& data_paths) {
-  Status s = CreateAndNewDirectory(env, dbname, &db_dir_);
+  Status s = DBImpl::CreateAndNewDirectory(env, dbname, &db_dir_);
  if (!s.ok()) {
    return s;
  }
  if (!wal_dir.empty() && dbname != wal_dir) {
-    s = CreateAndNewDirectory(env, wal_dir, &wal_dir_);
+    s = DBImpl::CreateAndNewDirectory(env, wal_dir, &wal_dir_);
    if (!s.ok()) {
      return s;
    }
@@ -292,7 +287,7 @@ Status DBImpl::Directories::SetDirectories(
      data_dirs_.emplace_back(nullptr);
    } else {
      std::unique_ptr<Directory> path_directory;
-      s = CreateAndNewDirectory(env, db_path, &path_directory);
+      s = DBImpl::CreateAndNewDirectory(env, db_path, &path_directory);
      if (!s.ok()) {
        return s;
      }
@@ -385,6 +380,14 @@ Status DBImpl::Recover(
  if (immutable_db_options_.paranoid_checks && s.ok()) {
    s = CheckConsistency();
  }
+  if (s.ok() && !read_only) {
+    for (auto cfd : *versions_->GetColumnFamilySet()) {
+      s = cfd->AddDirectories();
+      if (!s.ok()) {
+        return s;
+      }
+    }
+  }
  if (s.ok()) {
    SequenceNumber next_sequence(kMaxSequenceNumber);
    default_cf_handle_ = new ColumnFamilyHandleImpl(
@@ -529,6 +532,13 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
  bool flushed = false;
  uint64_t corrupted_log_number = kMaxSequenceNumber;
  for (auto log_number : log_numbers) {
+    if (log_number < versions_->min_log_number_to_keep_2pc()) {
+      ROCKS_LOG_INFO(immutable_db_options_.info_log,
+                     "Skipping log #%" PRIu64
+                     " since it is older than min log to keep #%" PRIu64,
+                     log_number, versions_->min_log_number_to_keep_2pc());
+      continue;
+    }
    // The previous incarnation may not have written any MANIFEST
    // records after allocating this log number.  So we manually
    // update the file number allocation counter in VersionSet.
@@ -962,7 +972,7 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
                  meta.marked_for_compaction);
  }

-  InternalStats::CompactionStats stats(1);
+  InternalStats::CompactionStats stats(CompactionReason::kFlush, 1);
  stats.micros = env_->NowMicros() - start_micros;
  stats.bytes_written = meta.fd.GetFileSize();
  stats.num_output_files = 1;
@@ -1024,8 +1034,17 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
  DBImpl* impl = new DBImpl(db_options, dbname, seq_per_batch);
  s = impl->env_->CreateDirIfMissing(impl->immutable_db_options_.wal_dir);
  if (s.ok()) {
-    for (auto db_path : impl->immutable_db_options_.db_paths) {
-      s = impl->env_->CreateDirIfMissing(db_path.path);
+    std::vector<std::string> paths;
+    for (auto& db_path : impl->immutable_db_options_.db_paths) {
+      paths.emplace_back(db_path.path);
+    }
+    for (auto& cf : column_families) {
+      for (auto& cf_path : cf.options.cf_paths) {
+        paths.emplace_back(cf_path.path);
+      }
+    }
+    for (auto& path : paths) {
+      s = impl->env_->CreateDirIfMissing(path);
      if (!s.ok()) {
        break;
      }
@@ -1071,7 +1090,8 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
            new_log_number,
            new log::Writer(
                std::move(file_writer), new_log_number,
-                impl->immutable_db_options_.recycle_log_file_num > 0));
+                impl->immutable_db_options_.recycle_log_file_num > 0,
+                impl->immutable_db_options_.manual_wal_flush));
      }

      // set column family handles
@@ -1168,17 +1188,28 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
      impl->immutable_db_options_.sst_file_manager.get());
  if (s.ok() && sfm) {
    // Notify SstFileManager about all sst files that already exist in
-    // db_paths[0] when the DB is opened.
-    auto& db_path = impl->immutable_db_options_.db_paths[0];
-    std::vector<std::string> existing_files;
-    impl->immutable_db_options_.env->GetChildren(db_path.path, &existing_files);
-    for (auto& file_name : existing_files) {
-      uint64_t file_number;
-      FileType file_type;
-      std::string file_path = db_path.path + "/" + file_name;
-      if (ParseFileName(file_name, &file_number, &file_type) &&
-          file_type == kTableFile) {
-        sfm->OnAddFile(file_path);
+    // db_paths[0] and cf_paths[0] when the DB is opened.
+    std::vector<std::string> paths;
+    paths.emplace_back(impl->immutable_db_options_.db_paths[0].path);
+    for (auto& cf : column_families) {
+      if (!cf.options.cf_paths.empty()) {
+        paths.emplace_back(cf.options.cf_paths[0].path);
+      }
+    }
+    // Remove duplicate paths.
+    std::sort(paths.begin(), paths.end());
+    paths.erase(std::unique(paths.begin(), paths.end()), paths.end());
+    for (auto& path : paths) {
+      std::vector<std::string> existing_files;
+      impl->immutable_db_options_.env->GetChildren(path, &existing_files);
+      for (auto& file_name : existing_files) {
+        uint64_t file_number;
+        FileType file_type;
+        std::string file_path = path + "/" + file_name;
+        if (ParseFileName(file_name, &file_number, &file_type) &&
+            file_type == kTableFile) {
+          sfm->OnAddFile(file_path);
+        }
      }
    }
  }
@@ -1187,6 +1218,9 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
  if (s.ok()) {
    ROCKS_LOG_INFO(impl->immutable_db_options_.info_log, "DB pointer %p", impl);
    LogFlush(impl->immutable_db_options_.info_log);
+    assert(impl->TEST_WALBufferIsEmpty());
+    // If the assert above fails then we need to FlushWAL before returning
+    // control back to the user.
    if (!persist_options_status.ok()) {
      s = Status::IOError(
          "DB::Open() failed --- Unable to persist Options file",
@@ -24,8 +24,7 @@ DBImplReadOnly::DBImplReadOnly(const DBOptions& db_options,
  LogFlush(immutable_db_options_.info_log);
 }

-DBImplReadOnly::~DBImplReadOnly() {
-}
+DBImplReadOnly::~DBImplReadOnly() {}

 // Implementations of the DB interface
 Status DBImplReadOnly::Get(const ReadOptions& read_options,
@@ -59,7 +58,7 @@ Iterator* DBImplReadOnly::NewIterator(const ReadOptions& read_options,
  SequenceNumber latest_snapshot = versions_->LastSequence();
  ReadCallback* read_callback = nullptr;  // No read callback provided.
  auto db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, *cfd->ioptions(),
+      env_, read_options, *cfd->ioptions(), super_version->mutable_cf_options,
      (read_options.snapshot != nullptr
           ? reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)
                 ->number_
@@ -89,7 +88,7 @@ Status DBImplReadOnly::NewIterators(
    auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh)->cfd();
    auto* sv = cfd->GetSuperVersion()->Ref();
    auto* db_iter = NewArenaWrappedDbIterator(
-        env_, read_options, *cfd->ioptions(),
+        env_, read_options, *cfd->ioptions(), sv->mutable_cf_options,
        (read_options.snapshot != nullptr
             ? reinterpret_cast<const SnapshotImpl*>(read_options.snapshot)
                   ->number_
@@ -183,20 +182,21 @@ Status DB::OpenForReadOnly(
  return s;
 }

-#else  // !ROCKSDB_LITE
+#else   // !ROCKSDB_LITE

-Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
-                           DB** dbptr, bool error_if_log_file_exist) {
+Status DB::OpenForReadOnly(const Options& /*options*/,
+                           const std::string& /*dbname*/, DB** /*dbptr*/,
+                           bool /*error_if_log_file_exist*/) {
  return Status::NotSupported("Not supported in ROCKSDB_LITE.");
 }

 Status DB::OpenForReadOnly(
-    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) {
+    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*/) {
  return Status::NotSupported("Not supported in ROCKSDB_LITE.");
 }
 #endif  // !ROCKSDB_LITE

-}   // namespace rocksdb
+}  // namespace rocksdb
@@ -45,6 +45,11 @@ Status DBImpl::SingleDelete(const WriteOptions& write_options,
  return DB::SingleDelete(write_options, column_family, key);
 }

+void DBImpl::SetRecoverableStatePreReleaseCallback(
+    PreReleaseCallback* callback) {
+  recoverable_state_pre_release_callback_.reset(callback);
+}
+
 Status DBImpl::Write(const WriteOptions& write_options, WriteBatch* my_batch) {
  return WriteImpl(write_options, my_batch, nullptr, nullptr);
 }
@@ -117,15 +122,19 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
  write_thread_.JoinBatchGroup(&w);
  if (w.state == WriteThread::STATE_PARALLEL_MEMTABLE_WRITER) {
    // we are a non-leader in a parallel group
-    PERF_TIMER_GUARD(write_memtable_time);

    if (w.ShouldWriteToMemtable()) {
+      PERF_TIMER_STOP(write_pre_and_post_process_time);
+      PERF_TIMER_GUARD(write_memtable_time);
+
      ColumnFamilyMemTablesImpl column_family_memtables(
          versions_->GetColumnFamilySet());
      w.status = WriteBatchInternal::InsertInto(
          &w, w.sequence, &column_family_memtables, &flush_scheduler_,
          write_options.ignore_missing_column_families, 0 /*log_number*/, this,
          true /*concurrent_memtable_writes*/, seq_per_batch_, w.batch_cnt);
+
+      PERF_TIMER_START(write_pre_and_post_process_time);
    }

    if (write_thread_.CompleteParallelMemTableWriter(&w)) {
@@ -133,7 +142,8 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
      for (auto* writer : *(w.write_group)) {
        if (!writer->CallbackFailed() && writer->pre_release_callback) {
          assert(writer->sequence != kMaxSequenceNumber);
-          Status ws = writer->pre_release_callback->Callback(writer->sequence);
+          Status ws = writer->pre_release_callback->Callback(writer->sequence,
+                                                             disable_memtable);
          if (!ws.ok()) {
            status = ws;
            break;
@@ -184,7 +194,13 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    // With concurrent writes we do preprocess only in the write thread that
    // also does write to memtable to avoid sync issue on shared data structure
    // with the other thread
+
+    // PreprocessWrite does its own perf timing.
+    PERF_TIMER_STOP(write_pre_and_post_process_time);
+
    status = PreprocessWrite(write_options, &need_log_sync, &write_context);
+
+    PERF_TIMER_START(write_pre_and_post_process_time);
  }
  log::Writer* log_writer = logs_.back().writer;

@@ -195,6 +211,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
  // and protects against concurrent loggers and concurrent writes
  // into memtables

+  TEST_SYNC_POINT("DBImpl::WriteImpl:BeforeLeaderEnters");
  last_batch_group_size_ =
      write_thread_.EnterAsBatchGroupLeader(&w, &write_group);

@@ -339,7 +356,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
  PERF_TIMER_START(write_pre_and_post_process_time);

  if (!w.CallbackFailed()) {
-    WriteCallbackStatusCheck(status);
+    WriteStatusCheck(status);
  }

  if (need_log_sync) {
@@ -347,7 +364,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    MarkLogsSynced(logfile_number_, need_log_dir_sync, status);
    mutex_.Unlock();
    // Requesting sync with two_write_queues_ is expected to be very rare. We
-    // hance provide a simple implementation that is not necessarily efficient.
+    // hence provide a simple implementation that is not necessarily efficient.
    if (two_write_queues_) {
      if (manual_wal_flush_) {
        status = FlushWAL(true);
@@ -368,7 +385,8 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
      for (auto* writer : write_group) {
        if (!writer->CallbackFailed() && writer->pre_release_callback) {
          assert(writer->sequence != kMaxSequenceNumber);
-          Status ws = writer->pre_release_callback->Callback(writer->sequence);
+          Status ws = writer->pre_release_callback->Callback(writer->sequence,
+                                                             disable_memtable);
          if (!ws.ok()) {
            status = ws;
            break;
@@ -407,7 +425,10 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
    mutex_.Lock();
    bool need_log_sync = !write_options.disableWAL && write_options.sync;
    bool need_log_dir_sync = need_log_sync && !log_dir_synced_;
+    // PreprocessWrite does its own perf timing.
+    PERF_TIMER_STOP(write_pre_and_post_process_time);
    w.status = PreprocessWrite(write_options, &need_log_sync, &write_context);
+    PERF_TIMER_START(write_pre_and_post_process_time);
    log::Writer* log_writer = logs_.back().writer;
    mutex_.Unlock();

@@ -462,7 +483,7 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
    }

    if (!w.CallbackFailed()) {
-      WriteCallbackStatusCheck(w.status);
+      WriteStatusCheck(w.status);
    }

    if (need_log_sync) {
@@ -623,13 +644,15 @@ Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
  PERF_TIMER_START(write_pre_and_post_process_time);

  if (!w.CallbackFailed()) {
-    WriteCallbackStatusCheck(status);
+    WriteStatusCheck(status);
  }
  if (status.ok()) {
    for (auto* writer : write_group) {
      if (!writer->CallbackFailed() && writer->pre_release_callback) {
        assert(writer->sequence != kMaxSequenceNumber);
-        Status ws = writer->pre_release_callback->Callback(writer->sequence);
+        const bool DISABLE_MEMTABLE = true;
+        Status ws = writer->pre_release_callback->Callback(writer->sequence,
+                                                           DISABLE_MEMTABLE);
        if (!ws.ok()) {
          status = ws;
          break;
@@ -647,7 +670,7 @@ Status DBImpl::WriteImplWALOnly(const WriteOptions& write_options,
  return status;
 }

-void DBImpl::WriteCallbackStatusCheck(const Status& status) {
+void DBImpl::WriteStatusCheck(const Status& status) {
  // Is setting bg_error_ enough here?  This will at least stop
  // compaction and fail any further writes.
  if (immutable_db_options_.paranoid_checks && !status.ok() &&
@@ -695,6 +718,8 @@ Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
  assert(write_context != nullptr && need_log_sync != nullptr);
  Status status;

+  PERF_TIMER_GUARD(write_scheduling_flushes_compactions_time);
+
  assert(!single_column_family_mode_ ||
         versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1);
  if (UNLIKELY(status.ok() && !single_column_family_mode_ &&
@@ -719,14 +744,19 @@ Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
    status = ScheduleFlushes(write_context);
  }

+  PERF_TIMER_STOP(write_scheduling_flushes_compactions_time);
+  PERF_TIMER_GUARD(write_pre_and_post_process_time);
+
  if (UNLIKELY(status.ok() && (write_controller_.IsStopped() ||
                               write_controller_.NeedsDelay()))) {
+    PERF_TIMER_STOP(write_pre_and_post_process_time);
    PERF_TIMER_GUARD(write_delay_time);
    // We don't know size of curent batch so that we always use the size
    // for previous one. It might create a fairness issue that expiration
    // might happen for smaller writes but larger writes can go through.
    // Can optimize it if it is an issue.
    status = DelayWrite(last_batch_group_size_, write_options);
+    PERF_TIMER_START(write_pre_and_post_process_time);
  }

  if (status.ok() && *need_log_sync) {
@@ -804,7 +834,21 @@ Status DBImpl::WriteToWAL(const WriteBatch& merged_batch,
  assert(log_size != nullptr);
  Slice log_entry = WriteBatchInternal::Contents(&merged_batch);
  *log_size = log_entry.size();
+  // When two_write_queues_ WriteToWAL has to be protected from concurretn calls
+  // from the two queues anyway and log_write_mutex_ is already held. Otherwise
+  // if manual_wal_flush_ is enabled we need to protect log_writer->AddRecord
+  // from possible concurrent calls via the FlushWAL by the application.
+  const bool needs_locking = manual_wal_flush_ && !two_write_queues_;
+  // Due to performance cocerns of missed branch prediction penalize the new
+  // manual_wal_flush_ feature (by UNLIKELY) instead of the more common case
+  // when we do not need any locking.
+  if (UNLIKELY(needs_locking)) {
+    log_write_mutex_.Lock();
+  }
  Status status = log_writer->AddRecord(log_entry);
+  if (UNLIKELY(needs_locking)) {
+    log_write_mutex_.Unlock();
+  }
  if (log_used != nullptr) {
    *log_used = logfile_number_;
  }
@@ -942,7 +986,12 @@ Status DBImpl::WriteRecoverableState() {
    if (two_write_queues_) {
      log_write_mutex_.Lock();
    }
-    SequenceNumber seq = versions_->LastSequence();
+    SequenceNumber seq;
+    if (two_write_queues_) {
+      seq = versions_->FetchAddLastAllocatedSequence(0);
+    } else {
+      seq = versions_->LastSequence();
+    }
    WriteBatchInternal::SetSequence(&cached_recoverable_state_, seq + 1);
    auto status = WriteBatchInternal::InsertInto(
        &cached_recoverable_state_, column_family_memtables_.get(),
@@ -952,12 +1001,20 @@ Status DBImpl::WriteRecoverableState() {
    auto last_seq = next_seq - 1;
    if (two_write_queues_) {
      versions_->FetchAddLastAllocatedSequence(last_seq - seq);
+      versions_->SetLastPublishedSequence(last_seq);
    }
    versions_->SetLastSequence(last_seq);
-    versions_->SetLastPublishedSequence(last_seq);
    if (two_write_queues_) {
      log_write_mutex_.Unlock();
    }
+    if (status.ok() && recoverable_state_pre_release_callback_) {
+      const bool DISABLE_MEMTABLE = true;
+      for (uint64_t sub_batch_seq = seq + 1;
+           sub_batch_seq < next_seq && status.ok(); sub_batch_seq++) {
+        status = recoverable_state_pre_release_callback_->Callback(
+            sub_batch_seq, !DISABLE_MEMTABLE);
+      }
+    }
    if (status.ok()) {
      cached_recoverable_state_.Clear();
      cached_recoverable_state_empty_ = true;
@@ -977,28 +1034,34 @@ Status DBImpl::SwitchWAL(WriteContext* write_context) {
  }

  auto oldest_alive_log = alive_log_files_.begin()->number;
-  auto oldest_log_with_uncommited_prep = FindMinLogContainingOutstandingPrep();
+  bool flush_wont_release_oldest_log = false;
+  if (allow_2pc()) {
+    auto oldest_log_with_uncommited_prep =
+        logs_with_prep_tracker_.FindMinLogContainingOutstandingPrep();

-  if (allow_2pc() &&
-      oldest_log_with_uncommited_prep > 0 &&
-      oldest_log_with_uncommited_prep <= oldest_alive_log) {
-    if (unable_to_flush_oldest_log_) {
+    assert(oldest_log_with_uncommited_prep == 0 ||
+           oldest_log_with_uncommited_prep >= oldest_alive_log);
+    if (oldest_log_with_uncommited_prep > 0 &&
+        oldest_log_with_uncommited_prep == oldest_alive_log) {
+      if (unable_to_release_oldest_log_) {
        // we already attempted to flush all column families dependent on
-        // the oldest alive log but the log still contained uncommited transactions.
-        // the oldest alive log STILL contains uncommited transaction so there
-        // is still nothing that we can do.
+        // the oldest alive log but the log still contained uncommited
+        // transactions so there is still nothing that we can do.
        return status;
-    } else {
-      ROCKS_LOG_WARN(
-          immutable_db_options_.info_log,
-          "Unable to release oldest log due to uncommited transaction");
-      unable_to_flush_oldest_log_ = true;
+      } else {
+        ROCKS_LOG_WARN(
+            immutable_db_options_.info_log,
+            "Unable to release oldest log due to uncommited transaction");
+        unable_to_release_oldest_log_ = true;
+        flush_wont_release_oldest_log = true;
+      }
    }
-  } else {
+  }
+  if (!flush_wont_release_oldest_log) {
    // we only mark this log as getting flushed if we have successfully
    // flushed all data in this log. If this log contains outstanding prepared
    // transactions then we cannot flush this log until those transactions are commited.
-    unable_to_flush_oldest_log_ = false;
+    unable_to_release_oldest_log_ = false;
    alive_log_files_.begin()->getting_flushed = true;
  }

@@ -1062,7 +1125,8 @@ Status DBImpl::HandleWriteBufferFull(WriteContext* write_context) {
    }
  }
  if (cfd_picked != nullptr) {
-    status = SwitchMemtable(cfd_picked, write_context);
+    status = SwitchMemtable(cfd_picked, write_context,
+                            FlushReason::kWriteBufferFull);
    if (status.ok()) {
      cfd_picked->imm()->FlushRequested();
      SchedulePendingFlush(cfd_picked, FlushReason::kWriteBufferFull);
@@ -1152,6 +1216,7 @@ Status DBImpl::ThrottleLowPriWritesIfNeeded(const WriteOptions& write_options,
      // is that in case the write is heavy, low pri writes may never have
      // a chance to run. Now we guarantee we are still slowly making
      // progress.
+      PERF_TIMER_GUARD(write_delay_time);
      write_controller_.low_pri_rate_limiter()->Request(
          my_batch->GetDataSize(), Env::IO_HIGH, nullptr /* stats */,
          RateLimiter::OpType::kWrite);
@@ -1163,7 +1228,7 @@ Status DBImpl::ThrottleLowPriWritesIfNeeded(const WriteOptions& write_options,
 Status DBImpl::ScheduleFlushes(WriteContext* context) {
  ColumnFamilyData* cfd;
  while ((cfd = flush_scheduler_.TakeNextColumnFamily()) != nullptr) {
-    auto status = SwitchMemtable(cfd, context);
+    auto status = SwitchMemtable(cfd, context, FlushReason::kWriteBufferFull);
    if (cfd->Unref()) {
      delete cfd;
    }
@@ -1192,7 +1257,8 @@ void DBImpl::NotifyOnMemTableSealed(ColumnFamilyData* /*cfd*/,

 // REQUIRES: mutex_ is held
 // REQUIRES: this thread is currently at the front of the writer queue
-Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
+Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
+                              FlushReason flush_reason) {
  mutex_.AssertHeld();
  WriteThread::Writer nonmem_w;
  if (two_write_queues_) {
@@ -1360,7 +1426,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
  new_mem->Ref();
  cfd->SetMemtable(new_mem);
  InstallSuperVersionAndScheduleWork(cfd, &context->superversion_context,
-                                     mutable_cf_options);
+                                     mutable_cf_options, flush_reason);
  if (two_write_queues_) {
    nonmem_write_thread_.ExitUnbatched(&nonmem_w);
  }
@@ -30,6 +30,7 @@ class InternalIterator;
 // into appropriate user keys.
 extern Iterator* NewDBIterator(Env* env, const ReadOptions& read_options,
                               const ImmutableCFOptions& cf_options,
+                               const MutableCFOptions& mutable_cf_options,
                               const Comparator* user_key_comparator,
                               InternalIterator* internal_iter,
                               const SequenceNumber& sequence,
@@ -71,6 +72,7 @@ class ArenaWrappedDBIter : public Iterator {

  void Init(Env* env, const ReadOptions& read_options,
            const ImmutableCFOptions& cf_options,
+            const MutableCFOptions& mutable_cf_options,
            const SequenceNumber& sequence,
            uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
            ReadCallback* read_callback, bool allow_blob, bool allow_refresh);
@@ -102,7 +104,8 @@ class ArenaWrappedDBIter : public Iterator {
 // be supported.
 extern ArenaWrappedDBIter* NewArenaWrappedDbIterator(
    Env* env, const ReadOptions& read_options,
-    const ImmutableCFOptions& cf_options, const SequenceNumber& sequence,
+    const ImmutableCFOptions& cf_options,
+    const MutableCFOptions& mutable_cf_options, const SequenceNumber& sequence,
    uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
    ReadCallback* read_callback, DBImpl* db_impl = nullptr,
    ColumnFamilyData* cfd = nullptr, bool allow_blob = false,
@@ -0,0 +1,654 @@
+//  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/db_iter.h"
+#include "db/dbformat.h"
+#include "rocksdb/comparator.h"
+#include "rocksdb/options.h"
+#include "rocksdb/slice.h"
+#include "util/random.h"
+#include "util/string_util.h"
+#include "util/testharness.h"
+#include "utilities/merge_operators.h"
+
+#ifdef GFLAGS
+
+#include "util/gflags_compat.h"
+
+using GFLAGS_NAMESPACE::ParseCommandLineFlags;
+
+DEFINE_bool(verbose, false,
+            "Print huge, detailed trace. Intended for debugging failures.");
+
+#else
+
+void ParseCommandLineFlags(int*, char***, bool) {}
+bool FLAGS_verbose = false;
+
+#endif
+
+namespace rocksdb {
+
+class DBIteratorStressTest : public testing::Test {
+ public:
+  Env* env_;
+
+  DBIteratorStressTest() : env_(Env::Default()) {}
+};
+
+namespace {
+
+struct Entry {
+  std::string key;
+  ValueType type;  // kTypeValue, kTypeDeletion, kTypeMerge
+  uint64_t sequence;
+  std::string ikey;  // internal key, made from `key`, `sequence` and `type`
+  std::string value;
+  // If false, we'll pretend that this entry doesn't exist.
+  bool visible = true;
+
+  bool operator<(const Entry& e) const {
+    if (key != e.key) return key < e.key;
+    return std::tie(sequence, type) > std::tie(e.sequence, e.type);
+  }
+};
+
+struct Data {
+  std::vector<Entry> entries;
+
+  // Indices in `entries` with `visible` = false.
+  std::vector<size_t> hidden;
+  // Keys of entries whose `visible` changed since the last seek of iterators.
+  std::set<std::string> recently_touched_keys;
+};
+
+struct StressTestIterator : public InternalIterator {
+  Data* data;
+  Random64* rnd;
+  InternalKeyComparator cmp;
+
+  // Each operation will return error with this probability...
+  double error_probability = 0;
+  // ... and add/remove entries with this probability.
+  double mutation_probability = 0;
+  // The probability of adding vs removing entries will be chosen so that the
+  // amount of removed entries stays somewhat close to this number.
+  double target_hidden_fraction = 0;
+  // If true, print all mutations to stdout for debugging.
+  bool trace = false;
+
+  int iter = -1;
+  Status status_;
+
+  StressTestIterator(Data* _data, Random64* _rnd, const Comparator* _cmp)
+      : data(_data), rnd(_rnd), cmp(_cmp) {}
+
+  bool Valid() const override {
+    if (iter >= 0 && iter < (int)data->entries.size()) {
+      assert(status_.ok());
+      return true;
+    }
+    return false;
+  }
+
+  Status status() const override { return status_; }
+
+  bool MaybeFail() {
+    if (rnd->Next() >=
+        std::numeric_limits<uint64_t>::max() * error_probability) {
+      return false;
+    }
+    if (rnd->Next() % 2) {
+      status_ = Status::Incomplete("test");
+    } else {
+      status_ = Status::IOError("test");
+    }
+    if (trace) {
+      std::cout << "injecting " << status_.ToString() << std::endl;
+    }
+    iter = -1;
+    return true;
+  }
+
+  void MaybeMutate() {
+    if (rnd->Next() >=
+        std::numeric_limits<uint64_t>::max() * mutation_probability) {
+      return;
+    }
+    do {
+      // If too many entries are hidden, hide less, otherwise hide more.
+      double hide_probability =
+          data->hidden.size() > data->entries.size() * target_hidden_fraction
+              ? 1. / 3
+              : 2. / 3;
+      if (data->hidden.empty()) {
+        hide_probability = 1;
+      }
+      bool do_hide =
+          rnd->Next() < std::numeric_limits<uint64_t>::max() * hide_probability;
+      if (do_hide) {
+        // Hide a random entry.
+        size_t idx = rnd->Next() % data->entries.size();
+        Entry& e = data->entries[idx];
+        if (e.visible) {
+          if (trace) {
+            std::cout << "hiding idx " << idx << std::endl;
+          }
+          e.visible = false;
+          data->hidden.push_back(idx);
+          data->recently_touched_keys.insert(e.key);
+        } else {
+          // Already hidden. Let's go unhide something instead, just because
+          // it's easy and it doesn't really matter what we do.
+          do_hide = false;
+        }
+      }
+      if (!do_hide) {
+        // Unhide a random entry.
+        size_t hi = rnd->Next() % data->hidden.size();
+        size_t idx = data->hidden[hi];
+        if (trace) {
+          std::cout << "unhiding idx " << idx << std::endl;
+        }
+        Entry& e = data->entries[idx];
+        assert(!e.visible);
+        e.visible = true;
+        data->hidden[hi] = data->hidden.back();
+        data->hidden.pop_back();
+        data->recently_touched_keys.insert(e.key);
+      }
+    } while (rnd->Next() % 3 != 0);  // do 3 mutations on average
+  }
+
+  void SkipForward() {
+    while (iter < (int)data->entries.size() && !data->entries[iter].visible) {
+      ++iter;
+    }
+  }
+  void SkipBackward() {
+    while (iter >= 0 && !data->entries[iter].visible) {
+      --iter;
+    }
+  }
+
+  void SeekToFirst() override {
+    if (MaybeFail()) return;
+    MaybeMutate();
+
+    status_ = Status::OK();
+    iter = 0;
+    SkipForward();
+  }
+  void SeekToLast() override {
+    if (MaybeFail()) return;
+    MaybeMutate();
+
+    status_ = Status::OK();
+    iter = (int)data->entries.size() - 1;
+    SkipBackward();
+  }
+
+  void Seek(const Slice& target) override {
+    if (MaybeFail()) return;
+    MaybeMutate();
+
+    status_ = Status::OK();
+    // Binary search.
+    auto it = std::partition_point(
+        data->entries.begin(), data->entries.end(),
+        [&](const Entry& e) { return cmp.Compare(e.ikey, target) < 0; });
+    iter = (int)(it - data->entries.begin());
+    SkipForward();
+  }
+  void SeekForPrev(const Slice& target) override {
+    if (MaybeFail()) return;
+    MaybeMutate();
+
+    status_ = Status::OK();
+    // Binary search.
+    auto it = std::partition_point(
+        data->entries.begin(), data->entries.end(),
+        [&](const Entry& e) { return cmp.Compare(e.ikey, target) <= 0; });
+    iter = (int)(it - data->entries.begin());
+    --iter;
+    SkipBackward();
+  }
+
+  void Next() override {
+    assert(Valid());
+    if (MaybeFail()) return;
+    MaybeMutate();
+    ++iter;
+    SkipForward();
+  }
+  void Prev() override {
+    assert(Valid());
+    if (MaybeFail()) return;
+    MaybeMutate();
+    --iter;
+    SkipBackward();
+  }
+
+  Slice key() const override {
+    assert(Valid());
+    return data->entries[iter].ikey;
+  }
+  Slice value() const override {
+    assert(Valid());
+    return data->entries[iter].value;
+  }
+
+  bool IsKeyPinned() const override { return true; }
+  bool IsValuePinned() const override { return true; }
+};
+
+// A small reimplementation of DBIter, supporting only some of the features,
+// and doing everything in O(log n).
+// Skips all keys that are in recently_touched_keys.
+struct ReferenceIterator {
+  Data* data;
+  uint64_t sequence;  // ignore entries with sequence number below this
+
+  bool valid = false;
+  std::string key;
+  std::string value;
+
+  ReferenceIterator(Data* _data, uint64_t _sequence)
+      : data(_data), sequence(_sequence) {}
+
+  bool Valid() const { return valid; }
+
+  // Finds the first entry with key
+  // greater/less/greater-or-equal/less-or-equal than `key`, depending on
+  // arguments: if `skip`, inequality is strict; if `forward`, it's
+  // greater/greater-or-equal, otherwise less/less-or-equal.
+  // Sets `key` to the result.
+  // If no such key exists, returns false. Doesn't check `visible`.
+  bool FindNextKey(bool skip, bool forward) {
+    valid = false;
+    auto it = std::partition_point(data->entries.begin(), data->entries.end(),
+                                   [&](const Entry& e) {
+                                     if (forward != skip) {
+                                       return e.key < key;
+                                     } else {
+                                       return e.key <= key;
+                                     }
+                                   });
+    if (forward) {
+      if (it != data->entries.end()) {
+        key = it->key;
+        return true;
+      }
+    } else {
+      if (it != data->entries.begin()) {
+        --it;
+        key = it->key;
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool FindValueForCurrentKey() {
+    if (data->recently_touched_keys.count(key)) {
+      return false;
+    }
+
+    // Find the first entry for the key. The caller promises that it exists.
+    auto it = std::partition_point(data->entries.begin(), data->entries.end(),
+                                   [&](const Entry& e) {
+                                     if (e.key != key) {
+                                       return e.key < key;
+                                     }
+                                     return e.sequence > sequence;
+                                   });
+
+    // Find the first visible entry.
+    for (;; ++it) {
+      if (it == data->entries.end()) {
+        return false;
+      }
+      Entry& e = *it;
+      if (e.key != key) {
+        return false;
+      }
+      assert(e.sequence <= sequence);
+      if (!e.visible) continue;
+      if (e.type == kTypeDeletion) {
+        return false;
+      }
+      if (e.type == kTypeValue) {
+        value = e.value;
+        valid = true;
+        return true;
+      }
+      assert(e.type == kTypeMerge);
+      break;
+    }
+
+    // Collect merge operands.
+    std::vector<Slice> operands;
+    for (; it != data->entries.end(); ++it) {
+      Entry& e = *it;
+      if (e.key != key) {
+        break;
+      }
+      assert(e.sequence <= sequence);
+      if (!e.visible) continue;
+      if (e.type == kTypeDeletion) {
+        break;
+      }
+      operands.push_back(e.value);
+      if (e.type == kTypeValue) {
+        break;
+      }
+    }
+
+    // Do a merge.
+    value = operands.back().ToString();
+    for (int i = (int)operands.size() - 2; i >= 0; --i) {
+      value.append(",");
+      value.append(operands[i].data(), operands[i].size());
+    }
+
+    valid = true;
+    return true;
+  }
+
+  // Start at `key` and move until we encounter a valid value.
+  // `forward` defines the direction of movement.
+  // If `skip` is true, we're looking for key not equal to `key`.
+  void DoTheThing(bool skip, bool forward) {
+    while (FindNextKey(skip, forward) && !FindValueForCurrentKey()) {
+      skip = true;
+    }
+  }
+
+  void Seek(const Slice& target) {
+    key = target.ToString();
+    DoTheThing(false, true);
+  }
+  void SeekForPrev(const Slice& target) {
+    key = target.ToString();
+    DoTheThing(false, false);
+  }
+  void SeekToFirst() { Seek(""); }
+  void SeekToLast() {
+    key = data->entries.back().key;
+    DoTheThing(false, false);
+  }
+  void Next() {
+    assert(Valid());
+    DoTheThing(true, true);
+  }
+  void Prev() {
+    assert(Valid());
+    DoTheThing(true, false);
+  }
+};
+
+}  // namespace
+
+// Use an internal iterator that sometimes returns errors and sometimes
+// adds/removes entries on the fly. Do random operations on a DBIter and
+// check results.
+// TODO: can be improved for more coverage:
+//   * Override IsKeyPinned() and IsValuePinned() to actually use
+//     PinnedIteratorManager and check that there's no use-after free.
+//   * Try different combinations of prefix_extractor, total_order_seek,
+//     prefix_same_as_start, iterate_lower_bound, iterate_upper_bound.
+TEST_F(DBIteratorStressTest, StressTest) {
+  // We use a deterministic RNG, and everything happens in a single thread.
+  Random64 rnd(826909345792864532ll);
+
+  auto gen_key = [&](int max_key) {
+    assert(max_key > 0);
+    int len = 0;
+    int a = max_key;
+    while (a) {
+      a /= 10;
+      ++len;
+    }
+    std::string s = ToString(rnd.Next() % static_cast<uint64_t>(max_key));
+    s.insert(0, len - (int)s.size(), '0');
+    return s;
+  };
+
+  Options options;
+  options.merge_operator = MergeOperators::CreateFromStringId("stringappend");
+  ReadOptions ropt;
+
+  size_t num_matching = 0;
+  size_t num_at_end = 0;
+  size_t num_not_ok = 0;
+  size_t num_recently_removed = 0;
+
+  // Number of iterations for each combination of parameters
+  // (there are ~250 of those).
+  // Tweak this to change the test run time.
+  // As of the time of writing, the test takes ~4 seconds for value of 5000.
+  const int num_iterations = 5000;
+  // Enable this to print all the operations for debugging.
+  bool trace = FLAGS_verbose;
+
+  for (int num_entries : {5, 10, 100}) {
+    for (double key_space : {0.1, 1.0, 3.0}) {
+      for (ValueType prevalent_entry_type :
+           {kTypeValue, kTypeDeletion, kTypeMerge}) {
+        for (double error_probability : {0.01, 0.1}) {
+          for (double mutation_probability : {0.01, 0.5}) {
+            for (double target_hidden_fraction : {0.1, 0.5}) {
+              std::string trace_str =
+                  "entries: " + ToString(num_entries) +
+                  ", key_space: " + ToString(key_space) +
+                  ", error_probability: " + ToString(error_probability) +
+                  ", mutation_probability: " + ToString(mutation_probability) +
+                  ", target_hidden_fraction: " +
+                  ToString(target_hidden_fraction);
+              SCOPED_TRACE(trace_str);
+              if (trace) {
+                std::cout << trace_str << std::endl;
+              }
+
+              // Generate data.
+              Data data;
+              int max_key = (int)(num_entries * key_space) + 1;
+              for (int i = 0; i < num_entries; ++i) {
+                Entry e;
+                e.key = gen_key(max_key);
+                if (rnd.Next() % 10 != 0) {
+                  e.type = prevalent_entry_type;
+                } else {
+                  const ValueType types[] = {kTypeValue, kTypeDeletion,
+                                             kTypeMerge};
+                  e.type =
+                      types[rnd.Next() % (sizeof(types) / sizeof(types[0]))];
+                }
+                e.sequence = i;
+                e.value = "v" + ToString(i);
+                ParsedInternalKey internal_key(e.key, e.sequence, e.type);
+                AppendInternalKey(&e.ikey, internal_key);
+
+                data.entries.push_back(e);
+              }
+              std::sort(data.entries.begin(), data.entries.end());
+              if (trace) {
+                std::cout << "entries:";
+                for (size_t i = 0; i < data.entries.size(); ++i) {
+                  Entry& e = data.entries[i];
+                  std::cout
+                      << "\n  idx " << i << ": \"" << e.key << "\": \""
+                      << e.value << "\" seq: " << e.sequence << " type: "
+                      << (e.type == kTypeValue
+                              ? "val"
+                              : e.type == kTypeDeletion ? "del" : "merge");
+                }
+                std::cout << std::endl;
+              }
+
+              std::unique_ptr<Iterator> db_iter;
+              std::unique_ptr<ReferenceIterator> ref_iter;
+              for (int iteration = 0; iteration < num_iterations; ++iteration) {
+                SCOPED_TRACE(iteration);
+                // Create a new iterator every ~30 operations.
+                if (db_iter == nullptr || rnd.Next() % 30 == 0) {
+                  uint64_t sequence = rnd.Next() % (data.entries.size() + 2);
+                  ref_iter.reset(new ReferenceIterator(&data, sequence));
+                  if (trace) {
+                    std::cout << "new iterator, seq: " << sequence << std::endl;
+                  }
+
+                  auto internal_iter =
+                      new StressTestIterator(&data, &rnd, BytewiseComparator());
+                  internal_iter->error_probability = error_probability;
+                  internal_iter->mutation_probability = mutation_probability;
+                  internal_iter->target_hidden_fraction =
+                      target_hidden_fraction;
+                  internal_iter->trace = trace;
+                  db_iter.reset(NewDBIterator(
+                      env_, ropt, ImmutableCFOptions(options),
+                      MutableCFOptions(options), BytewiseComparator(),
+                      internal_iter, sequence,
+                      options.max_sequential_skip_in_iterations,
+                      nullptr /*read_callback*/));
+                }
+
+                // Do a random operation. It's important to do it on ref_it
+                // later than on db_iter to make sure ref_it sees the correct
+                // recently_touched_keys.
+                std::string old_key;
+                bool forward = rnd.Next() % 2 > 0;
+                // Do Next()/Prev() ~90% of the time.
+                bool seek = !ref_iter->Valid() || rnd.Next() % 10 == 0;
+                if (trace) {
+                  std::cout << iteration << ": ";
+                }
+
+                if (!seek) {
+                  assert(db_iter->Valid());
+                  old_key = ref_iter->key;
+                  if (trace) {
+                    std::cout << (forward ? "Next" : "Prev") << std::endl;
+                  }
+
+                  if (forward) {
+                    db_iter->Next();
+                    ref_iter->Next();
+                  } else {
+                    db_iter->Prev();
+                    ref_iter->Prev();
+                  }
+                } else {
+                  data.recently_touched_keys.clear();
+                  // Do SeekToFirst less often than Seek.
+                  if (rnd.Next() % 4 == 0) {
+                    if (trace) {
+                      std::cout << (forward ? "SeekToFirst" : "SeekToLast")
+                                << std::endl;
+                    }
+
+                    if (forward) {
+                      old_key = "";
+                      db_iter->SeekToFirst();
+                      ref_iter->SeekToFirst();
+                    } else {
+                      old_key = data.entries.back().key;
+                      db_iter->SeekToLast();
+                      ref_iter->SeekToLast();
+                    }
+                  } else {
+                    old_key = gen_key(max_key);
+                    if (trace) {
+                      std::cout << (forward ? "Seek" : "SeekForPrev") << " \""
+                                << old_key << '"' << std::endl;
+                    }
+                    if (forward) {
+                      db_iter->Seek(old_key);
+                      ref_iter->Seek(old_key);
+                    } else {
+                      db_iter->SeekForPrev(old_key);
+                      ref_iter->SeekForPrev(old_key);
+                    }
+                  }
+                }
+
+                // Check the result.
+                if (db_iter->Valid()) {
+                  ASSERT_TRUE(db_iter->status().ok());
+                  if (data.recently_touched_keys.count(
+                          db_iter->key().ToString())) {
+                    // Ended on a key that may have been mutated during the
+                    // operation. Reference iterator skips such keys, so we
+                    // can't check the exact result.
+
+                    // Check that the key moved in the right direction.
+                    if (forward) {
+                      if (seek)
+                        ASSERT_GE(db_iter->key().ToString(), old_key);
+                      else
+                        ASSERT_GT(db_iter->key().ToString(), old_key);
+                    } else {
+                      if (seek)
+                        ASSERT_LE(db_iter->key().ToString(), old_key);
+                      else
+                        ASSERT_LT(db_iter->key().ToString(), old_key);
+                    }
+
+                    if (ref_iter->Valid()) {
+                      // Check that DBIter didn't miss any non-mutated key.
+                      if (forward) {
+                        ASSERT_LT(db_iter->key().ToString(), ref_iter->key);
+                      } else {
+                        ASSERT_GT(db_iter->key().ToString(), ref_iter->key);
+                      }
+                    }
+                    // Tell the next iteration of the loop to reseek the
+                    // iterators.
+                    ref_iter->valid = false;
+
+                    ++num_recently_removed;
+                  } else {
+                    ASSERT_TRUE(ref_iter->Valid());
+                    ASSERT_EQ(ref_iter->key, db_iter->key().ToString());
+                    ASSERT_EQ(ref_iter->value, db_iter->value());
+                    ++num_matching;
+                  }
+                } else if (db_iter->status().ok()) {
+                  ASSERT_FALSE(ref_iter->Valid());
+                  ++num_at_end;
+                } else {
+                  // Non-ok status. Nothing to check here.
+                  // Tell the next iteration of the loop to reseek the
+                  // iterators.
+                  ref_iter->valid = false;
+                  ++num_not_ok;
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  // Check that all cases were hit many times.
+  EXPECT_GT(num_matching, 10000);
+  EXPECT_GT(num_at_end, 10000);
+  EXPECT_GT(num_not_ok, 10000);
+  EXPECT_GT(num_recently_removed, 10000);
+
+  std::cout << "stats:\n  exact matches: " << num_matching
+            << "\n  end reached: " << num_at_end
+            << "\n  non-ok status: " << num_not_ok
+            << "\n  mutated on the fly: " << num_recently_removed << std::endl;
+}
+
+}  // namespace rocksdb
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  ParseCommandLineFlags(&argc, &argv, true);
+  return RUN_ALL_TESTS();
+}
@@ -862,6 +862,8 @@ TEST_P(DBIteratorTest, IteratorPinsRef) {
  } while (ChangeCompactOptions());
 }

+// SetOptions not defined in ROCKSDB LITE
+#ifndef ROCKSDB_LITE
 TEST_P(DBIteratorTest, DBIteratorBoundTest) {
  Options options = CurrentOptions();
  options.env = env_;
@@ -946,9 +948,7 @@ TEST_P(DBIteratorTest, DBIteratorBoundTest) {
  }

  // prefix is the first letter of the key
-  options.prefix_extractor.reset(NewFixedPrefixTransform(1));
-
-  DestroyAndReopen(options);
+  ASSERT_OK(dbfull()->SetOptions({{"prefix_extractor", "fixed:1"}}));
  ASSERT_OK(Put("a", "0"));
  ASSERT_OK(Put("foo", "bar"));
  ASSERT_OK(Put("foo1", "bar1"));
@@ -1035,6 +1035,7 @@ TEST_P(DBIteratorTest, DBIteratorBoundTest) {
    ASSERT_EQ(static_cast<int>(get_perf_context()->internal_delete_skipped_count), 0);
  }
 }
+#endif

 TEST_P(DBIteratorTest, DBIteratorBoundOptimizationTest) {
  int upper_bound_hits = 0;
@@ -2043,43 +2044,6 @@ TEST_P(DBIteratorTest, CreationFailure) {
  delete iter;
 }

-TEST_P(DBIteratorTest, UpperBoundWithChangeDirection) {
-  Options options = CurrentOptions();
-  options.max_sequential_skip_in_iterations = 3;
-  DestroyAndReopen(options);
-
-  // write a bunch of kvs to the database.
-  ASSERT_OK(Put("a", "1"));
-  ASSERT_OK(Put("y", "1"));
-  ASSERT_OK(Put("y1", "1"));
-  ASSERT_OK(Put("y2", "1"));
-  ASSERT_OK(Put("y3", "1"));
-  ASSERT_OK(Put("z", "1"));
-  ASSERT_OK(Flush());
-  ASSERT_OK(Put("a", "1"));
-  ASSERT_OK(Put("z", "1"));
-  ASSERT_OK(Put("bar", "1"));
-  ASSERT_OK(Put("foo", "1"));
-
-  std::string upper_bound = "x";
-  Slice ub_slice(upper_bound);
-  ReadOptions ro;
-  ro.iterate_upper_bound = &ub_slice;
-  ro.max_skippable_internal_keys = 1000;
-
-  Iterator* iter = NewIterator(ro);
-  iter->Seek("foo");
-  ASSERT_TRUE(iter->Valid());
-  ASSERT_EQ("foo", iter->key().ToString());
-
-  iter->Prev();
-  ASSERT_TRUE(iter->Valid());
-  ASSERT_OK(iter->status());
-  ASSERT_EQ("bar", iter->key().ToString());
-
-  delete iter;
-}
-
 TEST_P(DBIteratorTest, TableFilter) {
  ASSERT_OK(Put("a", "1"));
  dbfull()->Flush(FlushOptions());
@@ -2146,47 +2110,6 @@ TEST_P(DBIteratorTest, TableFilter) {
  }
 }

-TEST_P(DBIteratorTest, UpperBoundWithPrevReseek) {
-  Options options = CurrentOptions();
-  options.max_sequential_skip_in_iterations = 3;
-  DestroyAndReopen(options);
-
-  // write a bunch of kvs to the database.
-  ASSERT_OK(Put("a", "1"));
-  ASSERT_OK(Put("y", "1"));
-  ASSERT_OK(Put("z", "1"));
-  ASSERT_OK(Flush());
-  ASSERT_OK(Put("a", "1"));
-  ASSERT_OK(Put("z", "1"));
-  ASSERT_OK(Put("bar", "1"));
-  ASSERT_OK(Put("foo", "1"));
-  ASSERT_OK(Put("foo", "2"));
-
-  ASSERT_OK(Put("foo", "3"));
-  ASSERT_OK(Put("foo", "4"));
-  ASSERT_OK(Put("foo", "5"));
-  const Snapshot* snapshot = db_->GetSnapshot();
-  ASSERT_OK(Put("foo", "6"));
-
-  std::string upper_bound = "x";
-  Slice ub_slice(upper_bound);
-  ReadOptions ro;
-  ro.snapshot = snapshot;
-  ro.iterate_upper_bound = &ub_slice;
-
-  Iterator* iter = NewIterator(ro);
-  iter->SeekForPrev("goo");
-  ASSERT_TRUE(iter->Valid());
-  ASSERT_EQ("foo", iter->key().ToString());
-  iter->Prev();
-
-  ASSERT_TRUE(iter->Valid());
-  ASSERT_EQ("bar", iter->key().ToString());
-
-  delete iter;
-  db_->ReleaseSnapshot(snapshot);
-}
-
 TEST_P(DBIteratorTest, SkipStatistics) {
  Options options = CurrentOptions();
  options.statistics = rocksdb::CreateDBStatistics();
@@ -2310,6 +2233,46 @@ TEST_P(DBIteratorTest, SeekAfterHittingManyInternalKeys) {
  ASSERT_EQ(iter2->value().ToString(), "val_6");
 }

+// Reproduces a former bug where iterator would skip some records when DBIter
+// re-seeks subiterator with Incomplete status.
+TEST_P(DBIteratorTest, NonBlockingIterationBugRepro) {
+  Options options = CurrentOptions();
+  BlockBasedTableOptions table_options;
+  // Make sure the sst file has more than one block.
+  table_options.flush_block_policy_factory =
+      std::make_shared<FlushBlockEveryKeyPolicyFactory>();
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  DestroyAndReopen(options);
+
+  // Two records in sst file, each in its own block.
+  Put("b", "");
+  Put("d", "");
+  Flush();
+
+  // Create a nonblocking iterator before writing to memtable.
+  ReadOptions ropt;
+  ropt.read_tier = kBlockCacheTier;
+  unique_ptr<Iterator> iter(NewIterator(ropt));
+
+  // Overwrite a key in memtable many times to hit
+  // max_sequential_skip_in_iterations (which is 8 by default).
+  for (int i = 0; i < 20; ++i) {
+    Put("c", "");
+  }
+
+  // Load the second block in sst file into the block cache.
+  {
+    unique_ptr<Iterator> iter2(NewIterator(ReadOptions()));
+    iter2->Seek("d");
+  }
+
+  // Finally seek the nonblocking iterator.
+  iter->Seek("a");
+  // With the bug, the status used to be OK, and the iterator used to point to
+  // "d".
+  EXPECT_TRUE(iter->status().IsIncomplete());
+}
+
 INSTANTIATE_TEST_CASE_P(DBIteratorTestInstance, DBIteratorTest,
                        testing::Values(true, false));

@@ -134,7 +134,7 @@ TEST_F(DBOptionsTest, SetBytesPerSync) {
  const std::string kValue(kValueSize, 'v');
  ASSERT_EQ(options.bytes_per_sync, dbfull()->GetDBOptions().bytes_per_sync);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "WritableFileWriter::RangeSync:0", [&](void* arg) {
+      "WritableFileWriter::RangeSync:0", [&](void* /*arg*/) {
        counter++;
      });

@@ -183,7 +183,7 @@ TEST_F(DBOptionsTest, SetWalBytesPerSync) {
  int counter = 0;
  int low_bytes_per_sync = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "WritableFileWriter::RangeSync:0", [&](void* arg) {
+      "WritableFileWriter::RangeSync:0", [&](void* /*arg*/) {
        counter++;
      });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
@@ -242,11 +242,12 @@ TEST_F(DBOptionsTest, WritableFileMaxBufferSize) {
  ASSERT_EQ(unmatch_cnt, 0);
  ASSERT_GE(match_cnt, 11);

-  buffer_size = 512 * 1024;
-  match_cnt = 0;
-  unmatch_cnt = 0;
  ASSERT_OK(
      dbfull()->SetDBOptions({{"writable_file_max_buffer_size", "524288"}}));
+  buffer_size = 512 * 1024;
+  match_cnt = 0;
+  unmatch_cnt = 0;  // SetDBOptions() will create a WriteableFileWriter
+
  ASSERT_EQ(buffer_size,
            dbfull()->GetDBOptions().writable_file_max_buffer_size);
  i = 0;
@@ -69,27 +69,27 @@ TEST_F(DBPropertiesTest, Empty) {
    ASSERT_OK(db_->DisableFileDeletions());
    ASSERT_TRUE(
        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
-    ASSERT_EQ("1", num);
+    ASSERT_EQ("0", num);

    ASSERT_OK(db_->DisableFileDeletions());
    ASSERT_TRUE(
        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
-    ASSERT_EQ("2", num);
+    ASSERT_EQ("0", num);

    ASSERT_OK(db_->DisableFileDeletions());
    ASSERT_TRUE(
        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
-    ASSERT_EQ("3", num);
+    ASSERT_EQ("0", num);

    ASSERT_OK(db_->EnableFileDeletions(false));
    ASSERT_TRUE(
        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
-    ASSERT_EQ("2", num);
+    ASSERT_EQ("0", num);

    ASSERT_OK(db_->EnableFileDeletions());
    ASSERT_TRUE(
        dbfull()->GetProperty("rocksdb.is-file-deletions-enabled", &num));
-    ASSERT_EQ("0", num);
+    ASSERT_EQ("1", num);
  } while (ChangeOptions());
 }

@@ -1436,6 +1436,107 @@ TEST_F(DBPropertiesTest, SstFilesSize) {
  ASSERT_TRUE(listener->callback_triggered);
 }

+TEST_F(DBPropertiesTest, BlockCacheProperties) {
+  Options options;
+  uint64_t value;
+
+  // Block cache properties are not available for tables other than
+  // block-based table.
+  options.table_factory.reset(NewPlainTableFactory());
+  Reopen(options);
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_FALSE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+
+  options.table_factory.reset(NewCuckooTableFactory());
+  Reopen(options);
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_FALSE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+
+  // Block cache properties are not available if block cache is not used.
+  BlockBasedTableOptions table_options;
+  table_options.no_block_cache = true;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  Reopen(options);
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_FALSE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_FALSE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+
+  // Test with empty block cache.
+  constexpr size_t kCapacity = 100;
+  auto block_cache = NewLRUCache(kCapacity, 0 /*num_shard_bits*/);
+  table_options.block_cache = block_cache;
+  table_options.no_block_cache = false;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  Reopen(options);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_EQ(kCapacity, value);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_EQ(0, value);
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+  ASSERT_EQ(0, value);
+
+  // Insert unpinned item to the cache and check size.
+  constexpr size_t kSize1 = 50;
+  block_cache->Insert("item1", nullptr /*value*/, kSize1, nullptr /*deleter*/);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_EQ(kCapacity, value);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_EQ(kSize1, value);
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+  ASSERT_EQ(0, value);
+
+  // Insert pinned item to the cache and check size.
+  constexpr size_t kSize2 = 30;
+  Cache::Handle* item2 = nullptr;
+  block_cache->Insert("item2", nullptr /*value*/, kSize2, nullptr /*deleter*/,
+                      &item2);
+  ASSERT_NE(nullptr, item2);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_EQ(kCapacity, value);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  ASSERT_EQ(kSize1 + kSize2, value);
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+  ASSERT_EQ(kSize2, value);
+
+  // Insert another pinned item to make the cache over-sized.
+  constexpr size_t kSize3 = 80;
+  Cache::Handle* item3 = nullptr;
+  block_cache->Insert("item3", nullptr /*value*/, kSize3, nullptr /*deleter*/,
+                      &item3);
+  ASSERT_NE(nullptr, item2);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_EQ(kCapacity, value);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  // Item 1 is evicted.
+  ASSERT_EQ(kSize2 + kSize3, value);
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+  ASSERT_EQ(kSize2 + kSize3, value);
+
+  // Check size after release.
+  block_cache->Release(item2);
+  block_cache->Release(item3);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheCapacity, &value));
+  ASSERT_EQ(kCapacity, value);
+  ASSERT_TRUE(db_->GetIntProperty(DB::Properties::kBlockCacheUsage, &value));
+  // item2 will be evicted, while item3 remain in cache after release.
+  ASSERT_EQ(kSize3, value);
+  ASSERT_TRUE(
+      db_->GetIntProperty(DB::Properties::kBlockCachePinnedUsage, &value));
+  ASSERT_EQ(0, value);
+}
+
 #endif  // ROCKSDB_LITE
 }  // namespace rocksdb

@@ -433,8 +433,8 @@ TEST_F(DBRangeDelTest, ValidUniversalSubcompactionBoundaries) {
      reinterpret_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())
          ->cfd(),
      1 /* input_level */, 2 /* output_level */, 0 /* output_path_id */,
-      nullptr /* begin */, nullptr /* end */, true /* exclusive */,
-      true /* disallow_trivial_move */));
+      0 /* max_subcompactions */, nullptr /* begin */, nullptr /* end */,
+      true /* exclusive */, true /* disallow_trivial_move */));
 }
 #endif  // ROCKSDB_LITE

@@ -20,6 +20,37 @@ class DBSSTTest : public DBTestBase {
  DBSSTTest() : DBTestBase("/db_sst_test") {}
 };

+#ifndef ROCKSDB_LITE
+// A class which remembers the name of each flushed file.
+class FlushedFileCollector : public EventListener {
+ public:
+  FlushedFileCollector() {}
+  ~FlushedFileCollector() {}
+
+  virtual void OnFlushCompleted(DB* /*db*/, const FlushJobInfo& info) override {
+    std::lock_guard<std::mutex> lock(mutex_);
+    flushed_files_.push_back(info.file_path);
+  }
+
+  std::vector<std::string> GetFlushedFiles() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    std::vector<std::string> result;
+    for (auto fname : flushed_files_) {
+      result.push_back(fname);
+    }
+    return result;
+  }
+  void ClearFlushedFiles() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    flushed_files_.clear();
+  }
+
+ private:
+  std::vector<std::string> flushed_files_;
+  std::mutex mutex_;
+};
+#endif  // ROCKSDB_LITE
+
 TEST_F(DBSSTTest, DontDeletePendingOutputs) {
  Options options;
  options.env = env_;
@@ -72,7 +103,7 @@ TEST_F(DBSSTTest, SSTsWithLdbSuffixHandling) {
  ASSERT_GT(num_files, 0);

  std::vector<std::string> filenames;
-  GetSstFiles(dbname_, &filenames);
+  GetSstFiles(env_, dbname_, &filenames);
  int num_ldb_files = 0;
  for (size_t i = 0; i < filenames.size(); ++i) {
    if (i & 1) {
@@ -231,11 +262,11 @@ TEST_F(DBSSTTest, DBWithSstFileManager) {
  int files_deleted = 0;
  int files_moved = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "SstFileManagerImpl::OnAddFile", [&](void* arg) { files_added++; });
+      "SstFileManagerImpl::OnAddFile", [&](void* /*arg*/) { files_added++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "SstFileManagerImpl::OnDeleteFile", [&](void* arg) { files_deleted++; });
+      "SstFileManagerImpl::OnDeleteFile", [&](void* /*arg*/) { files_deleted++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "SstFileManagerImpl::OnMoveFile", [&](void* arg) { files_moved++; });
+      "SstFileManagerImpl::OnMoveFile", [&](void* /*arg*/) { files_moved++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -408,12 +439,12 @@ TEST_F(DBSSTTest, DeleteSchedulerMultipleDBPaths) {
  int bg_delete_file = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DeleteScheduler::DeleteTrashFile:DeleteFile",
-      [&](void* arg) { bg_delete_file++; });
+      [&](void* /*arg*/) { bg_delete_file++; });
  // The deletion scheduler sometimes skips marking file as trash according to
  // a heuristic. In that case the deletion will go through the below SyncPoint.
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DeleteScheduler::DeleteFile",
-      [&](void* arg) { bg_delete_file++; });
+      [&](void* /*arg*/) { bg_delete_file++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -483,7 +514,7 @@ TEST_F(DBSSTTest, DestroyDBWithRateLimitedDelete) {
  int bg_delete_file = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DeleteScheduler::DeleteTrashFile:DeleteFile",
-      [&](void* arg) { bg_delete_file++; });
+      [&](void* /*arg*/) { bg_delete_file++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Status s;
@@ -557,12 +588,13 @@ TEST_F(DBSSTTest, CancellingCompactionsWorks) {

  int completed_compactions = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction():CancelledCompaction", [&](void* arg) {
+      "DBImpl::BackgroundCompaction():CancelledCompaction", [&](void* /*arg*/) {
        sfm->SetMaxAllowedSpaceUsage(0);
+        ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
      });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial:AfterRun",
-      [&](void* arg) { completed_compactions++; });
+      [&](void* /*arg*/) { completed_compactions++; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Random rnd(301);
@@ -584,6 +616,8 @@ TEST_F(DBSSTTest, CancellingCompactionsWorks) {
  ASSERT_OK(Flush());
  dbfull()->TEST_WaitForCompact(true);

+  // Because we set a callback in CancelledCompaction, we actually
+  // let the compaction run
  ASSERT_GT(completed_compactions, 0);
  ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
  // Make sure the stat is bumped
@@ -591,6 +625,78 @@ TEST_F(DBSSTTest, CancellingCompactionsWorks) {
  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
 }

+TEST_F(DBSSTTest, CancellingManualCompactionsWorks) {
+  std::shared_ptr<SstFileManager> sst_file_manager(NewSstFileManager(env_));
+  auto sfm = static_cast<SstFileManagerImpl*>(sst_file_manager.get());
+
+  Options options = CurrentOptions();
+  options.sst_file_manager = sst_file_manager;
+  options.statistics = CreateDBStatistics();
+
+  FlushedFileCollector* collector = new FlushedFileCollector();
+  options.listeners.emplace_back(collector);
+
+  DestroyAndReopen(options);
+
+  Random rnd(301);
+
+  // Generate a file containing 10 keys.
+  for (int i = 0; i < 10; i++) {
+    ASSERT_OK(Put(Key(i), RandomString(&rnd, 50)));
+  }
+  ASSERT_OK(Flush());
+  uint64_t total_file_size = 0;
+  auto files_in_db = GetAllSSTFiles(&total_file_size);
+  // Set the maximum allowed space usage to the current total size
+  sfm->SetMaxAllowedSpaceUsage(2 * total_file_size + 1);
+
+  // Generate another file to trigger compaction.
+  for (int i = 0; i < 10; i++) {
+    ASSERT_OK(Put(Key(i), RandomString(&rnd, 50)));
+  }
+  ASSERT_OK(Flush());
+
+  // OK, now trigger a manual compaction
+  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+
+  // Wait for manual compaction to get scheduled and finish
+  dbfull()->TEST_WaitForCompact(true);
+
+  ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
+  // Make sure the stat is bumped
+  ASSERT_EQ(dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                COMPACTION_CANCELLED),
+            1);
+
+  // Now make sure CompactFiles also gets cancelled
+  auto l0_files = collector->GetFlushedFiles();
+  dbfull()->CompactFiles(rocksdb::CompactionOptions(), l0_files, 0);
+
+  // Wait for manual compaction to get scheduled and finish
+  dbfull()->TEST_WaitForCompact(true);
+
+  ASSERT_EQ(dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                COMPACTION_CANCELLED),
+            2);
+  ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
+
+  // Now let the flush through and make sure GetCompactionsReservedSize
+  // returns to normal
+  sfm->SetMaxAllowedSpaceUsage(0);
+  int completed_compactions = 0;
+  rocksdb::SyncPoint::GetInstance()->SetCallBack(
+      "CompactFilesImpl:End", [&](void* /*arg*/) { completed_compactions++; });
+
+  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
+  dbfull()->CompactFiles(rocksdb::CompactionOptions(), l0_files, 0);
+  dbfull()->TEST_WaitForCompact(true);
+
+  ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
+  ASSERT_GT(completed_compactions, 0);
+
+  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
+}
+
 TEST_F(DBSSTTest, DBWithMaxSpaceAllowedRandomized) {
  // This test will set a maximum allowed space for the DB, then it will
  // keep filling the DB until the limit is reached and bg_error_ is set.
@@ -627,7 +733,7 @@ TEST_F(DBSSTTest, DBWithMaxSpaceAllowedRandomized) {

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "CompactionJob::FinishCompactionOutputFile:MaxAllowedSpaceReached",
-      [&](void* arg) {
+      [&](void* /*arg*/) {
        bg_error_set = true;
        GetAllSSTFiles(&total_sst_files_size);
        reached_max_space_on_compaction++;
@@ -157,10 +157,10 @@ TEST_F(DBTestTailingIterator, TailingIteratorTrimSeekToNext) {
      });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "ForwardIterator::RenewIterators:Null",
-      [&](void* arg) { file_iters_renewed_null = true; });
+      [&](void* /*arg*/) { file_iters_renewed_null = true; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "ForwardIterator::RenewIterators:Copy",
-      [&](void* arg) { file_iters_renewed_copy = true; });
+      [&](void* /*arg*/) { file_iters_renewed_copy = true; });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
  const int num_records = 1000;
  for (int i = 1; i < num_records; ++i) {
@@ -415,7 +415,7 @@ TEST_F(DBTestTailingIterator, TailingIteratorUpperBound) {
  int immutable_seeks = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "ForwardIterator::SeekInternal:Immutable",
-      [&](void* arg) { ++immutable_seeks; });
+      [&](void* /*arg*/) { ++immutable_seeks; });

  // Seek to 13. This should not require any immutable seeks.
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
@@ -234,11 +234,11 @@ TEST_F(DBTest, SkipDelay) {
      std::atomic<int> sleep_count(0);
      rocksdb::SyncPoint::GetInstance()->SetCallBack(
          "DBImpl::DelayWrite:Sleep",
-          [&](void* arg) { sleep_count.fetch_add(1); });
+          [&](void* /*arg*/) { sleep_count.fetch_add(1); });
      std::atomic<int> wait_count(0);
      rocksdb::SyncPoint::GetInstance()->SetCallBack(
          "DBImpl::DelayWrite:Wait",
-          [&](void* arg) { wait_count.fetch_add(1); });
+          [&](void* /*arg*/) { wait_count.fetch_add(1); });
      rocksdb::SyncPoint::GetInstance()->EnableProcessing();

      WriteOptions wo;
@@ -2153,10 +2153,14 @@ TEST_F(DBTest, GroupCommitTest) {
  do {
    Options options = CurrentOptions();
    options.env = env_;
-    env_->log_write_slowdown_.store(100);
    options.statistics = rocksdb::CreateDBStatistics();
    Reopen(options);

+    rocksdb::SyncPoint::GetInstance()->LoadDependency(
+        {{"WriteThread::JoinBatchGroup:BeganWaiting",
+          "DBImpl::WriteImpl:BeforeLeaderEnters"}});
+    rocksdb::SyncPoint::GetInstance()->EnableProcessing();
+
    // Start threads
    GCThread thread[kGCNumThreads];
    for (int id = 0; id < kGCNumThreads; id++) {
@@ -2165,13 +2169,7 @@ TEST_F(DBTest, GroupCommitTest) {
      thread[id].done = false;
      env_->StartThread(GCThreadBody, &thread[id]);
    }
-
-    for (int id = 0; id < kGCNumThreads; id++) {
-      while (thread[id].done == false) {
-        env_->SleepForMicroseconds(100000);
-      }
-    }
-    env_->log_write_slowdown_.store(0);
+    env_->WaitForJoin();

    ASSERT_GT(TestGetTickerCount(options, WRITE_DONE_BY_OTHER), 0);

@@ -3348,6 +3346,56 @@ TEST_F(DBTest, WriteSingleThreadEntry) {
  }
 }

+TEST_F(DBTest, ConcurrentFlushWAL) {
+  const size_t cnt = 100;
+  Options options;
+  WriteOptions wopt;
+  ReadOptions ropt;
+  for (bool two_write_queues : {false, true}) {
+    for (bool manual_wal_flush : {false, true}) {
+      options.two_write_queues = two_write_queues;
+      options.manual_wal_flush = manual_wal_flush;
+      options.create_if_missing = true;
+      DestroyAndReopen(options);
+      std::vector<port::Thread> threads;
+      threads.emplace_back([&] {
+        for (size_t i = 0; i < cnt; i++) {
+          auto istr = ToString(i);
+          db_->Put(wopt, db_->DefaultColumnFamily(), "a" + istr, "b" + istr);
+        }
+      });
+      if (two_write_queues) {
+        threads.emplace_back([&] {
+          for (size_t i = cnt; i < 2 * cnt; i++) {
+            auto istr = ToString(i);
+            WriteBatch batch;
+            batch.Put("a" + istr, "b" + istr);
+            dbfull()->WriteImpl(wopt, &batch, nullptr, nullptr, 0, true);
+          }
+        });
+      }
+      threads.emplace_back([&] {
+        for (size_t i = 0; i < cnt * 100; i++) {  // FlushWAL is faster than Put
+          db_->FlushWAL(false);
+        }
+      });
+      for (auto& t : threads) {
+        t.join();
+      }
+      options.create_if_missing = false;
+      // Recover from the wal and make sure that it is not corrupted
+      Reopen(options);
+      for (size_t i = 0; i < cnt; i++) {
+        PinnableSlice pval;
+        auto istr = ToString(i);
+        ASSERT_OK(
+            db_->Get(ropt, db_->DefaultColumnFamily(), "a" + istr, &pval));
+        ASSERT_TRUE(pval == ("b" + istr));
+      }
+    }
+  }
+}
+
 #ifndef ROCKSDB_LITE
 TEST_F(DBTest, DynamicMemtableOptions) {
  const uint64_t k64KB = 1 << 16;
@@ -3441,7 +3489,7 @@ TEST_F(DBTest, DynamicMemtableOptions) {

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::DelayWrite:Wait",
-      [&](void* arg) { sleeping_task_low.WakeUp(); });
+      [&](void* /*arg*/) { sleeping_task_low.WakeUp(); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  while (!sleeping_task_low.WokenUp() && count < 256) {
@@ -4557,6 +4605,181 @@ TEST_F(DBTest, FileCreationRandomFailure) {
 }

 #ifndef ROCKSDB_LITE
+int CountIter(Iterator* iter, const Slice& key) {
+  int count = 0;
+  for (iter->Seek(key); iter->Valid() && iter->status() == Status::OK();
+       iter->Next()) {
+    count++;
+  }
+  return count;
+}
+
+// Create multiple SST files each with a different prefix_extractor config,
+// verify iterators can read all SST files using the latest config.
+TEST_F(DBTest, DynamicBloomFilterMultipleSST) {
+  Options options;
+  options.create_if_missing = true;
+  options.prefix_extractor.reset(NewFixedPrefixTransform(1));
+  options.disable_auto_compactions = true;
+  // Enable prefix bloom for SST files
+  BlockBasedTableOptions table_options;
+  table_options.filter_policy.reset(NewBloomFilterPolicy(10, true));
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  DestroyAndReopen(options);
+
+  ReadOptions read_options;
+  read_options.prefix_same_as_start = true;
+
+  // first SST with fixed:1 BF
+  ASSERT_OK(Put("foo2", "bar2"));
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Put("foq1", "bar1"));
+  ASSERT_OK(Put("fpa", "0"));
+  dbfull()->Flush(FlushOptions());
+  Iterator* iter_old = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_old, "foo"), 4);
+
+  ASSERT_OK(dbfull()->SetOptions({{"prefix_extractor", "capped:3"}}));
+  ASSERT_EQ(0, strcmp(dbfull()->GetOptions().prefix_extractor->Name(),
+                      "rocksdb.CappedPrefix.3"));
+  Iterator* iter = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter, "foo"), 2);
+
+  // second SST with capped:3 BF
+  ASSERT_OK(Put("foo3", "bar3"));
+  ASSERT_OK(Put("foo4", "bar4"));
+  ASSERT_OK(Put("foq5", "bar5"));
+  ASSERT_OK(Put("fpb", "1"));
+  dbfull()->Flush(FlushOptions());
+  // BF is cappped:3 now
+  Iterator* iter_tmp = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_tmp, "foo"), 4);
+  delete iter_tmp;
+
+  ASSERT_OK(dbfull()->SetOptions({{"prefix_extractor", "fixed:2"}}));
+  ASSERT_EQ(0, strcmp(dbfull()->GetOptions().prefix_extractor->Name(),
+                      "rocksdb.FixedPrefix.2"));
+  // third SST with fixed:2 BF
+  ASSERT_OK(Put("foo6", "bar6"));
+  ASSERT_OK(Put("foo7", "bar7"));
+  ASSERT_OK(Put("foq8", "bar8"));
+  ASSERT_OK(Put("fpc", "2"));
+  dbfull()->Flush(FlushOptions());
+  // BF is fixed:2 now
+  iter_tmp = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_tmp, "foo"), 9);
+  delete iter_tmp;
+
+  // TODO(Zhongyi): verify existing iterator cannot see newly inserted keys
+  ASSERT_EQ(CountIter(iter_old, "foo"), 4);
+  ASSERT_EQ(CountIter(iter, "foo"), 2);
+  delete iter;
+  delete iter_old;
+
+  // keys in all three SSTs are visible to iterator
+  Iterator* iter_all = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_all, "foo"), 9);
+  delete iter_all;
+  ASSERT_OK(dbfull()->SetOptions({{"prefix_extractor", "capped:3"}}));
+  ASSERT_EQ(0, strcmp(dbfull()->GetOptions().prefix_extractor->Name(),
+                      "rocksdb.CappedPrefix.3"));
+  iter_all = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_all, "foo"), 6);
+  delete iter_all;
+  // TODO(Zhongyi): add test for cases where certain SST are skipped
+  // Also verify BF related counters like BLOOM_FILTER_USEFUL
+}
+
+// Create a new column family in a running DB, change prefix_extractor
+// dynamically, verify the iterator created on the new column family behaves
+// as expected
+TEST_F(DBTest, DynamicBloomFilterNewColumnFamily) {
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  options.prefix_extractor.reset(NewFixedPrefixTransform(1));
+  options.disable_auto_compactions = true;
+  // Enable prefix bloom for SST files
+  BlockBasedTableOptions table_options;
+  table_options.filter_policy.reset(NewBloomFilterPolicy(10, true));
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  CreateAndReopenWithCF({"pikachu"}, options);
+  ReadOptions read_options;
+  read_options.prefix_same_as_start = true;
+  // create a new CF and set prefix_extractor dynamically
+  options.prefix_extractor.reset(NewCappedPrefixTransform(3));
+  CreateColumnFamilies({"ramen_dojo"}, options);
+  ASSERT_EQ(0,
+            strcmp(dbfull()->GetOptions(handles_[2]).prefix_extractor->Name(),
+                   "rocksdb.CappedPrefix.3"));
+  ASSERT_OK(Put(2, "foo3", "bar3"));
+  ASSERT_OK(Put(2, "foo4", "bar4"));
+  ASSERT_OK(Put(2, "foo5", "bar5"));
+  ASSERT_OK(Put(2, "foq6", "bar6"));
+  ASSERT_OK(Put(2, "fpq7", "bar7"));
+  dbfull()->Flush(FlushOptions());
+  Iterator* iter = db_->NewIterator(read_options, handles_[2]);
+  ASSERT_EQ(CountIter(iter, "foo"), 3);
+  delete iter;
+  ASSERT_OK(
+      dbfull()->SetOptions(handles_[2], {{"prefix_extractor", "fixed:2"}}));
+  ASSERT_EQ(0,
+            strcmp(dbfull()->GetOptions(handles_[2]).prefix_extractor->Name(),
+                   "rocksdb.FixedPrefix.2"));
+  iter = db_->NewIterator(read_options, handles_[2]);
+  ASSERT_EQ(CountIter(iter, "foo"), 4);
+  delete iter;
+}
+
+// Verify it's possible to change prefix_extractor at runtime and iterators
+// behaves as expected
+TEST_F(DBTest, DynamicBloomFilterOptions) {
+  Options options;
+  options.create_if_missing = true;
+  options.prefix_extractor.reset(NewFixedPrefixTransform(1));
+  options.disable_auto_compactions = true;
+  // Enable prefix bloom for SST files
+  BlockBasedTableOptions table_options;
+  table_options.filter_policy.reset(NewBloomFilterPolicy(10, true));
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  DestroyAndReopen(options);
+
+  ASSERT_OK(Put("foo2", "bar2"));
+  ASSERT_OK(Put("foo", "bar"));
+  ASSERT_OK(Put("foo1", "bar1"));
+  ASSERT_OK(Put("fpa", "0"));
+  dbfull()->Flush(FlushOptions());
+  ASSERT_OK(Put("foo3", "bar3"));
+  ASSERT_OK(Put("foo4", "bar4"));
+  ASSERT_OK(Put("foo5", "bar5"));
+  ASSERT_OK(Put("fpb", "1"));
+  dbfull()->Flush(FlushOptions());
+  ASSERT_OK(Put("foo6", "bar6"));
+  ASSERT_OK(Put("foo7", "bar7"));
+  ASSERT_OK(Put("foo8", "bar8"));
+  ASSERT_OK(Put("fpc", "2"));
+  dbfull()->Flush(FlushOptions());
+
+  ReadOptions read_options;
+  read_options.prefix_same_as_start = true;
+  Iterator* iter = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter, "foo"), 12);
+  delete iter;
+  Iterator* iter_old = db_->NewIterator(read_options);
+  ASSERT_EQ(CountIter(iter_old, "foo"), 12);
+
+  ASSERT_OK(dbfull()->SetOptions({{"prefix_extractor", "capped:3"}}));
+  ASSERT_EQ(0, strcmp(dbfull()->GetOptions().prefix_extractor->Name(),
+                      "rocksdb.CappedPrefix.3"));
+  iter = db_->NewIterator(read_options);
+  // "fp*" should be skipped
+  ASSERT_EQ(CountIter(iter, "foo"), 9);
+  delete iter;
+
+  // iterator created before should not be affected and see all keys
+  ASSERT_EQ(CountIter(iter_old, "foo"), 12);
+  delete iter_old;
+}
+
 TEST_F(DBTest, DynamicMiscOptions) {
  // Test max_sequential_skip_in_iterations
  Options options;
@@ -5144,7 +5367,7 @@ TEST_F(DBTest, AutomaticConflictsWithManualCompaction) {
  std::atomic<int> callback_count(0);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::MaybeScheduleFlushOrCompaction:Conflict",
-      [&](void* arg) { callback_count.fetch_add(1); });
+      [&](void* /*arg*/) { callback_count.fetch_add(1); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Random rnd(301);
@@ -5367,7 +5590,7 @@ TEST_F(DBTest, HardLimit) {

  std::atomic<int> callback_count(0);
  rocksdb::SyncPoint::GetInstance()->SetCallBack("DBImpl::DelayWrite:Wait",
-                                                 [&](void* arg) {
+                                                 [&](void* /*arg*/) {
                                                   callback_count.fetch_add(1);
                                                   sleeping_task_low.WakeUp();
                                                 });
@@ -5392,21 +5615,20 @@ TEST_F(DBTest, HardLimit) {
  sleeping_task_low.WaitUntilDone();
 }

-#ifndef ROCKSDB_LITE
+#if !defined(ROCKSDB_LITE) && !defined(ROCKSDB_DISABLE_STALL_NOTIFICATION)
 class WriteStallListener : public EventListener {
 public:
-  WriteStallListener() : cond_(&mutex_), 
-    condition_(WriteStallCondition::kNormal),
-    expected_(WriteStallCondition::kNormal),
-    expected_set_(false) 
-  {}
+  WriteStallListener()
+      : cond_(&mutex_),
+        condition_(WriteStallCondition::kNormal),
+        expected_(WriteStallCondition::kNormal),
+        expected_set_(false) {}
  void OnStallConditionsChanged(const WriteStallInfo& info) override {
    MutexLock l(&mutex_);
    condition_ = info.condition.cur;
-    if (expected_set_ && 
-      condition_ == expected_) {
-        cond_.Signal();
-        expected_set_ = false;
+    if (expected_set_ && condition_ == expected_) {
+      cond_.Signal();
+      expected_set_ = false;
    }
  }
  bool CheckCondition(WriteStallCondition expected) {
@@ -5504,7 +5726,7 @@ TEST_F(DBTest, SoftLimit) {

  // Only allow one compactin going through.
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "BackgroundCallCompaction:0", [&](void* arg) {
+      "BackgroundCallCompaction:0", [&](void* /*arg*/) {
        // Schedule a sleeping task.
        sleeping_task_low.Reset();
        env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask,
@@ -5614,7 +5836,7 @@ TEST_F(DBTest, LastWriteBufferDelay) {
  sleeping_task.WakeUp();
  sleeping_task.WaitUntilDone();
 }
-#endif  // ROCKSDB_LITE
+#endif  // !defined(ROCKSDB_LITE) && !defined(ROCKSDB_DISABLE_STALL_NOTIFICATION)

 TEST_F(DBTest, FailWhenCompressionNotSupportedTest) {
  CompressionType compressions[] = {kZlibCompression, kBZip2Compression,
@@ -1112,7 +1112,7 @@ TEST_F(DBTest2, PresetCompressionDict) {

      size_t out_bytes = 0;
      std::vector<std::string> files;
-      GetSstFiles(dbname_, &files);
+      GetSstFiles(env_, dbname_, &files);
      for (const auto& file : files) {
        uint64_t curr_bytes;
        env_->GetFileSize(dbname_ + "/" + file, &curr_bytes);
@@ -1691,7 +1691,7 @@ TEST_F(DBTest2, SyncPointMarker) {
  std::atomic<int> sync_point_called(0);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBTest2::MarkedPoint",
-      [&](void* arg) { sync_point_called.fetch_add(1); });
+      [&](void* /*arg*/) { sync_point_called.fetch_add(1); });

  // The first dependency enforces Marker can be loaded before MarkedPoint.
  // The second checks that thread 1's MarkedPoint should be disabled here.
@@ -1978,7 +1978,7 @@ TEST_F(DBTest2, AutomaticCompactionOverlapManualCompaction) {
  // can fit in L2, these 2 files will be moved to L2 and overlap with
  // the running compaction and break the LSM consistency.
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "CompactionJob::Run():Start", [&](void* arg) {
+      "CompactionJob::Run():Start", [&](void* /*arg*/) {
        ASSERT_OK(
            dbfull()->SetOptions({{"level0_file_num_compaction_trigger", "2"},
                                  {"max_bytes_for_level_base", "1"}}));
@@ -2044,7 +2044,7 @@ TEST_F(DBTest2, ManualCompactionOverlapManualCompaction) {
  // the running compaction and break the LSM consistency.
  std::atomic<bool> flag(false);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "CompactionJob::Run():Start", [&](void* arg) {
+      "CompactionJob::Run():Start", [&](void* /*arg*/) {
        if (flag.exchange(true)) {
          // We want to make sure to call this callback only once
          return;
@@ -2296,7 +2296,8 @@ TEST_F(DBTest2, RateLimitedCompactionReads) {
                             kBytesPerKey) /* rate_bytes_per_sec */,
        10 * 1000 /* refill_period_us */, 10 /* fairness */,
        RateLimiter::Mode::kReadsOnly));
-    options.use_direct_io_for_flush_and_compaction = use_direct_io;
+    options.use_direct_reads = options.use_direct_io_for_flush_and_compaction =
+        use_direct_io;
    BlockBasedTableOptions bbto;
    bbto.block_size = 16384;
    bbto.no_block_cache = true;
@@ -2318,7 +2319,7 @@ TEST_F(DBTest2, RateLimitedCompactionReads) {
    // chose 1MB as the upper bound on the total bytes read.
    size_t rate_limited_bytes =
        options.rate_limiter->GetTotalBytesThrough(Env::IO_LOW);
-    // Include the explict prefetch of the footer in direct I/O case.
+    // Include the explicit prefetch of the footer in direct I/O case.
    size_t direct_io_extra = use_direct_io ? 512 * 1024 : 0;
    ASSERT_GE(rate_limited_bytes,
              static_cast<size_t>(kNumKeysPerFile * kBytesPerKey * kNumL0Files +
@@ -2478,7 +2479,7 @@ TEST_F(DBTest2, LiveFilesOmitObsoleteFiles) {
  });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::PurgeObsoleteFiles:Begin",
-      [&](void* arg) { env_->SleepForMicroseconds(1000000); });
+      [&](void* /*arg*/) { env_->SleepForMicroseconds(1000000); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  Put("key", "val");
@@ -575,9 +575,17 @@ void DBTestBase::DestroyAndReopen(const Options& options) {
  ASSERT_OK(TryReopen(options));
 }

-void DBTestBase::Destroy(const Options& options) {
+void DBTestBase::Destroy(const Options& options, bool delete_cf_paths) {
+  std::vector<ColumnFamilyDescriptor> column_families;
+  if (delete_cf_paths) {
+    for (size_t i = 0; i < handles_.size(); ++i) {
+      ColumnFamilyDescriptor cfdescriptor;
+      handles_[i]->GetDescriptor(&cfdescriptor);
+      column_families.push_back(cfdescriptor);
+    }
+  }
  Close();
-  ASSERT_OK(DestroyDB(dbname_, options));
+  ASSERT_OK(DestroyDB(dbname_, options, column_families));
 }

 Status DBTestBase::ReadOnlyReopen(const Options& options) {
@@ -1017,9 +1025,9 @@ std::string DBTestBase::DumpSSTableList() {
  return property;
 }

-void DBTestBase::GetSstFiles(std::string path,
+void DBTestBase::GetSstFiles(Env* env, std::string path,
                             std::vector<std::string>* files) {
-  env_->GetChildren(path, files);
+  env->GetChildren(path, files);

  files->erase(
      std::remove_if(files->begin(), files->end(), [](std::string name) {
@@ -1031,7 +1039,7 @@ void DBTestBase::GetSstFiles(std::string path,

 int DBTestBase::GetSstFileCount(std::string path) {
  std::vector<std::string> files;
-  GetSstFiles(path, &files);
+  DBTestBase::GetSstFiles(env_, path, &files);
  return static_cast<int>(files.size());
 }

@@ -451,8 +451,9 @@ class SpecialEnv : public EnvWrapper {
    return s;
  }

-  Status NewSequentialFile(const std::string& f, unique_ptr<SequentialFile>* r,
-                           const EnvOptions& soptions) override {
+  virtual Status NewSequentialFile(const std::string& f,
+                                   unique_ptr<SequentialFile>* r,
+                                   const EnvOptions& soptions) override {
    class CountingFile : public SequentialFile {
     public:
      CountingFile(unique_ptr<SequentialFile>&& target,
@@ -605,7 +606,7 @@ class MockTimeEnv : public EnvWrapper {
  }

 private:
-  uint64_t current_time_ = 0;
+  std::atomic<uint64_t> current_time_{0};
 };

 #ifndef ROCKSDB_LITE
@@ -803,7 +804,7 @@ class DBTestBase : public testing::Test {

  void DestroyAndReopen(const Options& options);

-  void Destroy(const Options& options);
+  void Destroy(const Options& options, bool delete_cf_paths = false);

  Status ReadOnlyReopen(const Options& options);

@@ -903,7 +904,8 @@ class DBTestBase : public testing::Test {

  std::string DumpSSTableList();

-  void GetSstFiles(std::string path, std::vector<std::string>* files);
+  static void GetSstFiles(Env* env, std::string path,
+                          std::vector<std::string>* files);

  int GetSstFileCount(std::string path);

@@ -697,7 +697,7 @@ TEST_P(DBTestUniversalCompactionMultiLevels, UniversalCompactionTrivialMove) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial", [&](void* arg) {
        non_trivial_move++;
@@ -769,7 +769,7 @@ TEST_P(DBTestUniversalCompactionParallel, UniversalCompactionParallel) {
  std::atomic<int> num_compactions_running(0);
  std::atomic<bool> has_parallel(false);
  rocksdb::SyncPoint::GetInstance()->SetCallBack("CompactionJob::Run():Start",
-                                                 [&](void* arg) {
+                                                 [&](void* /*arg*/) {
    if (num_compactions_running.fetch_add(1) > 0) {
      has_parallel.store(true);
      return;
@@ -784,7 +784,7 @@ TEST_P(DBTestUniversalCompactionParallel, UniversalCompactionParallel) {
  });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "CompactionJob::Run():End",
-      [&](void* arg) { num_compactions_running.fetch_add(-1); });
+      [&](void* /*arg*/) { num_compactions_running.fetch_add(-1); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

  options = CurrentOptions(options);
@@ -1154,7 +1154,7 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionTrivialMoveTest1) {
  int32_t non_trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial", [&](void* arg) {
        non_trivial_move++;
@@ -1200,7 +1200,7 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionTrivialMoveTest2) {
  int32_t trivial_move = 0;
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:TrivialMove",
-      [&](void* arg) { trivial_move++; });
+      [&](void* /*arg*/) { trivial_move++; });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:NonTrivial", [&](void* arg) {
        ASSERT_TRUE(arg != nullptr);
@@ -1343,6 +1343,146 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionFourPaths) {
  Destroy(options);
 }

+TEST_P(DBTestUniversalCompaction, UniversalCompactionCFPathUse) {
+  Options options = CurrentOptions();
+  options.db_paths.emplace_back(dbname_, 300 * 1024);
+  options.db_paths.emplace_back(dbname_ + "_2", 300 * 1024);
+  options.db_paths.emplace_back(dbname_ + "_3", 500 * 1024);
+  options.db_paths.emplace_back(dbname_ + "_4", 1024 * 1024 * 1024);
+  options.memtable_factory.reset(
+      new SpecialSkipListFactory(KNumKeysByGenerateNewFile - 1));
+  options.compaction_style = kCompactionStyleUniversal;
+  options.compaction_options_universal.size_ratio = 5;
+  options.write_buffer_size = 111 << 10;  // 114KB
+  options.arena_block_size = 4 << 10;
+  options.level0_file_num_compaction_trigger = 2;
+  options.num_levels = 1;
+
+  std::vector<Options> option_vector;
+  option_vector.emplace_back(options);
+  ColumnFamilyOptions cf_opt1(options), cf_opt2(options);
+  // Configure CF1 specific paths.
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1", 300 * 1024);
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1_2", 300 * 1024);
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1_3", 500 * 1024);
+  cf_opt1.cf_paths.emplace_back(dbname_ + "cf1_4", 1024 * 1024 * 1024);
+  option_vector.emplace_back(DBOptions(options), cf_opt1);
+  CreateColumnFamilies({"one"},option_vector[1]);
+
+  // Configura CF2 specific paths.
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2", 300 * 1024);
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2_2", 300 * 1024);
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2_3", 500 * 1024);
+  cf_opt2.cf_paths.emplace_back(dbname_ + "cf2_4", 1024 * 1024 * 1024);
+  option_vector.emplace_back(DBOptions(options), cf_opt2);
+  CreateColumnFamilies({"two"},option_vector[2]);
+
+  ReopenWithColumnFamilies({"default", "one", "two"}, option_vector);
+
+  Random rnd(301);
+  int key_idx = 0;
+  int key_idx1 = 0;
+  int key_idx2 = 0;
+
+  auto generate_file = [&]() {
+    GenerateNewFile(0, &rnd, &key_idx);
+    GenerateNewFile(1, &rnd, &key_idx1);
+    GenerateNewFile(2, &rnd, &key_idx2);
+  };
+
+  auto check_sstfilecount = [&](int path_id, int expected) {
+    ASSERT_EQ(expected, GetSstFileCount(options.db_paths[path_id].path));
+    ASSERT_EQ(expected, GetSstFileCount(cf_opt1.cf_paths[path_id].path));
+    ASSERT_EQ(expected, GetSstFileCount(cf_opt2.cf_paths[path_id].path));
+  };
+
+  auto check_getvalues = [&]() {
+    for (int i = 0; i < key_idx; i++) {
+      auto v = Get(0, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+
+    for (int i = 0; i < key_idx1; i++) {
+      auto v = Get(1, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+
+    for (int i = 0; i < key_idx2; i++) {
+      auto v = Get(2, Key(i));
+      ASSERT_NE(v, "NOT_FOUND");
+      ASSERT_TRUE(v.size() == 1 || v.size() == 990);
+    }
+  };
+
+  // First three 110KB files are not going to second path.
+  // After that, (100K, 200K)
+  for (int num = 0; num < 3; num++) {
+    generate_file();
+  }
+
+  // Another 110KB triggers a compaction to 400K file to second path
+  generate_file();
+  check_sstfilecount(2, 1);
+
+  // (1, 4)
+  generate_file();
+  check_sstfilecount(2, 1);
+  check_sstfilecount(0, 1);
+
+  // (1,1,4) -> (2, 4)
+  generate_file();
+  check_sstfilecount(2, 1);
+  check_sstfilecount(1, 1);
+  check_sstfilecount(0, 0);
+
+  // (1, 2, 4) -> (3, 4)
+  generate_file();
+  check_sstfilecount(2, 1);
+  check_sstfilecount(1, 1);
+  check_sstfilecount(0, 0);
+
+  // (1, 3, 4) -> (8)
+  generate_file();
+  check_sstfilecount(3, 1);
+
+  // (1, 8)
+  generate_file();
+  check_sstfilecount(3, 1);
+  check_sstfilecount(0, 1);
+
+  // (1, 1, 8) -> (2, 8)
+  generate_file();
+  check_sstfilecount(3, 1);
+  check_sstfilecount(1, 1);
+
+  // (1, 2, 8) -> (3, 8)
+  generate_file();
+  check_sstfilecount(3, 1);
+  check_sstfilecount(1, 1);
+  check_sstfilecount(0, 0);
+
+  // (1, 3, 8) -> (4, 8)
+  generate_file();
+  check_sstfilecount(2, 1);
+  check_sstfilecount(3, 1);
+
+  // (1, 4, 8) -> (5, 8)
+  generate_file();
+  check_sstfilecount(3, 1);
+  check_sstfilecount(2, 1);
+  check_sstfilecount(0, 0);
+
+  check_getvalues();
+
+  ReopenWithColumnFamilies({"default", "one", "two"}, option_vector);
+
+  check_getvalues();
+
+  Destroy(options, true);
+}
+
 TEST_P(DBTestUniversalCompaction, IncreaseUniversalCompactionNumLevels) {
  std::function<void(int)> verify_func = [&](int num_keys_in_db) {
    std::string keys_in_db;
@@ -1540,50 +1680,6 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionSecondPathRatio) {
  Destroy(options);
 }

-TEST_P(DBTestUniversalCompaction, FullCompactionInBottomPriThreadPool) {
-  const int kNumFilesTrigger = 3;
-  Env::Default()->SetBackgroundThreads(1, Env::Priority::BOTTOM);
-  for (bool allow_ingest_behind : {false, true}) {
-    Options options = CurrentOptions();
-    options.allow_ingest_behind = allow_ingest_behind;
-    options.compaction_style = kCompactionStyleUniversal;
-    options.num_levels = num_levels_;
-    options.write_buffer_size = 100 << 10;     // 100KB
-    options.target_file_size_base = 32 << 10;  // 32KB
-    options.level0_file_num_compaction_trigger = kNumFilesTrigger;
-    // Trigger compaction if size amplification exceeds 110%
-    options.compaction_options_universal.max_size_amplification_percent = 110;
-    DestroyAndReopen(options);
-
-    int num_bottom_pri_compactions = 0;
-    SyncPoint::GetInstance()->SetCallBack(
-        "DBImpl::BGWorkBottomCompaction",
-        [&](void* arg) { ++num_bottom_pri_compactions; });
-    SyncPoint::GetInstance()->EnableProcessing();
-
-    Random rnd(301);
-    for (int num = 0; num < kNumFilesTrigger; num++) {
-      ASSERT_EQ(NumSortedRuns(), num);
-      int key_idx = 0;
-      GenerateNewFile(&rnd, &key_idx);
-    }
-    dbfull()->TEST_WaitForCompact();
-
-    if (allow_ingest_behind || num_levels_ > 1) {
-      // allow_ingest_behind increases number of levels while sanitizing.
-      ASSERT_EQ(1, num_bottom_pri_compactions);
-    } else {
-      // for single-level universal, everything's bottom level so nothing should
-      // be executed in bottom-pri thread pool.
-      ASSERT_EQ(0, num_bottom_pri_compactions);
-    }
-    // Verify that size amplification did occur
-    ASSERT_EQ(NumSortedRuns(), 1);
-    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
-  }
-  Env::Default()->SetBackgroundThreads(0, Env::Priority::BOTTOM);
-}
-
 TEST_P(DBTestUniversalCompaction, ConcurrentBottomPriLowPriCompactions) {
  if (num_levels_ == 1) {
    // for single-level universal, everything's bottom level so nothing should
@@ -1656,7 +1752,7 @@ TEST_P(DBTestUniversalCompaction, RecalculateScoreAfterPicking) {

  std::atomic<int> num_compactions_attempted(0);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::BackgroundCompaction:Start", [&](void* arg) {
+      "DBImpl::BackgroundCompaction:Start", [&](void* /*arg*/) {
        ++num_compactions_attempted;
      });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
@@ -20,6 +20,106 @@ class DBWALTest : public DBTestBase {
  DBWALTest() : DBTestBase("/db_wal_test") {}
 };

+// A SpecialEnv enriched to give more insight about deleted files
+class EnrichedSpecialEnv : public SpecialEnv {
+ public:
+  explicit EnrichedSpecialEnv(Env* base) : SpecialEnv(base) {}
+  Status NewSequentialFile(const std::string& f, unique_ptr<SequentialFile>* r,
+                           const EnvOptions& soptions) override {
+    InstrumentedMutexLock l(&env_mutex_);
+    if (f == skipped_wal) {
+      deleted_wal_reopened = true;
+      if (IsWAL(f) && largetest_deleted_wal.size() != 0 &&
+          f.compare(largetest_deleted_wal) <= 0) {
+        gap_in_wals = true;
+      }
+    }
+    return SpecialEnv::NewSequentialFile(f, r, soptions);
+  }
+  Status DeleteFile(const std::string& fname) override {
+    if (IsWAL(fname)) {
+      deleted_wal_cnt++;
+      InstrumentedMutexLock l(&env_mutex_);
+      // If this is the first WAL, remember its name and skip deleting it. We
+      // remember its name partly because the application might attempt to
+      // delete the file again.
+      if (skipped_wal.size() != 0 && skipped_wal != fname) {
+        if (largetest_deleted_wal.size() == 0 ||
+            largetest_deleted_wal.compare(fname) < 0) {
+          largetest_deleted_wal = fname;
+        }
+      } else {
+        skipped_wal = fname;
+        return Status::OK();
+      }
+    }
+    return SpecialEnv::DeleteFile(fname);
+  }
+  bool IsWAL(const std::string& fname) {
+    // printf("iswal %s\n", fname.c_str());
+    return fname.compare(fname.size() - 3, 3, "log") == 0;
+  }
+
+  InstrumentedMutex env_mutex_;
+  // the wal whose actual delete was skipped by the env
+  std::string skipped_wal = "";
+  // the largest WAL that was requested to be deleted
+  std::string largetest_deleted_wal = "";
+  // number of WALs that were successfully deleted
+  std::atomic<size_t> deleted_wal_cnt = {0};
+  // the WAL whose delete from fs was skipped is reopened during recovery
+  std::atomic<bool> deleted_wal_reopened = {false};
+  // whether a gap in the WALs was detected during recovery
+  std::atomic<bool> gap_in_wals = {false};
+};
+
+class DBWALTestWithEnrichedEnv : public DBTestBase {
+ public:
+  DBWALTestWithEnrichedEnv() : DBTestBase("/db_wal_test") {
+    enriched_env_ = new EnrichedSpecialEnv(env_->target());
+    auto options = CurrentOptions();
+    options.env = enriched_env_;
+    Reopen(options);
+    delete env_;
+    // to be deleted by the parent class
+    env_ = enriched_env_;
+  }
+
+ protected:
+  EnrichedSpecialEnv* enriched_env_;
+};
+
+// Test that the recovery would successfully avoid the gaps between the logs.
+// One known scenario that could cause this is that the application issue the
+// WAL deletion out of order. For the sake of simplicity in the test, here we
+// create the gap by manipulating the env to skip deletion of the first WAL but
+// not the ones after it.
+TEST_F(DBWALTestWithEnrichedEnv, SkipDeletedWALs) {
+  auto options = last_options_;
+  // To cause frequent WAL deletion
+  options.write_buffer_size = 128;
+  Reopen(options);
+
+  WriteOptions writeOpt = WriteOptions();
+  for (int i = 0; i < 128 * 5; i++) {
+    ASSERT_OK(dbfull()->Put(writeOpt, "foo", "v1"));
+  }
+  FlushOptions fo;
+  fo.wait = true;
+  ASSERT_OK(db_->Flush(fo));
+
+  // some wals are deleted
+  ASSERT_NE(0, enriched_env_->deleted_wal_cnt);
+  // but not the first one
+  ASSERT_NE(0, enriched_env_->skipped_wal.size());
+
+  // Test that the WAL that was not deleted will be skipped during recovery
+  options = last_options_;
+  Reopen(options);
+  ASSERT_FALSE(enriched_env_->deleted_wal_reopened);
+  ASSERT_FALSE(enriched_env_->gap_in_wals);
+}
+
 TEST_F(DBWALTest, WAL) {
  do {
    CreateAndReopenWithCF({"pikachu"}, CurrentOptions());
@@ -891,7 +991,7 @@ TEST_F(DBWALTest, kPointInTimeRecoveryCFConsistency) {

  // Record the offset at this point
  Env* env = options.env;
-  int wal_file_id = RecoveryTestHelper::kWALFileOffset + 1;
+  uint64_t wal_file_id = dbfull()->TEST_LogfileNumber();
  std::string fname = LogFileName(dbname_, wal_file_id);
  uint64_t offset_to_corrupt;
  ASSERT_OK(env->GetFileSize(fname, &offset_to_corrupt));
@@ -50,6 +50,7 @@ TEST_P(DBWriteTest, IOErrorOnWALWritePropagateToWriteThreadFollower) {
  std::atomic<int> leader_count{0};
  std::vector<port::Thread> threads;
  mock_env->SetFilesystemActive(false);
+
  // Wait until all threads linked to write threads, to make sure
  // all threads join the same batch group.
  SyncPoint::GetInstance()->SetCallBack(
@@ -68,7 +69,19 @@ TEST_P(DBWriteTest, IOErrorOnWALWritePropagateToWriteThreadFollower) {
    threads.push_back(port::Thread(
        [&](int index) {
          // All threads should fail.
-          ASSERT_FALSE(Put("key" + ToString(index), "value").ok());
+          auto res = Put("key" + ToString(index), "value");
+          if (options.manual_wal_flush) {
+            ASSERT_TRUE(res.ok());
+            // we should see fs error when we do the flush
+
+            // TSAN reports a false alarm for lock-order-inversion but Open and
+            // FlushWAL are not run concurrently. Disabling this until TSAN is
+            // fixed.
+            // res = dbfull()->FlushWAL(false);
+            // ASSERT_FALSE(res.ok());
+          } else {
+            ASSERT_FALSE(res.ok());
+          }
        },
        i));
  }
@@ -80,6 +93,53 @@ TEST_P(DBWriteTest, IOErrorOnWALWritePropagateToWriteThreadFollower) {
  Close();
 }

+TEST_P(DBWriteTest, ManualWalFlushInEffect) {
+  Options options = GetOptions();
+  Reopen(options);
+  // try the 1st WAL created during open
+  ASSERT_TRUE(Put("key" + ToString(0), "value").ok());
+  ASSERT_TRUE(options.manual_wal_flush != dbfull()->TEST_WALBufferIsEmpty());
+  ASSERT_TRUE(dbfull()->FlushWAL(false).ok());
+  ASSERT_TRUE(dbfull()->TEST_WALBufferIsEmpty());
+  // try the 2nd wal created during SwitchWAL
+  dbfull()->TEST_SwitchWAL();
+  ASSERT_TRUE(Put("key" + ToString(0), "value").ok());
+  ASSERT_TRUE(options.manual_wal_flush != dbfull()->TEST_WALBufferIsEmpty());
+  ASSERT_TRUE(dbfull()->FlushWAL(false).ok());
+  ASSERT_TRUE(dbfull()->TEST_WALBufferIsEmpty());
+}
+
+TEST_P(DBWriteTest, IOErrorOnWALWriteTriggersReadOnlyMode) {
+  std::unique_ptr<FaultInjectionTestEnv> mock_env(
+      new FaultInjectionTestEnv(Env::Default()));
+  Options options = GetOptions();
+  options.env = mock_env.get();
+  Reopen(options);
+  for (int i = 0; i < 2; i++) {
+    // Forcibly fail WAL write for the first Put only. Subsequent Puts should
+    // fail due to read-only mode
+    mock_env->SetFilesystemActive(i != 0);
+    auto res = Put("key" + ToString(i), "value");
+    // TSAN reports a false alarm for lock-order-inversion but Open and
+    // FlushWAL are not run concurrently. Disabling this until TSAN is
+    // fixed.
+    /*
+    if (options.manual_wal_flush && i == 0) {
+      // even with manual_wal_flush the 2nd Put should return error because of
+      // the read-only mode
+      ASSERT_TRUE(res.ok());
+      // we should see fs error when we do the flush
+      res = dbfull()->FlushWAL(false);
+    }
+    */
+    if (!options.manual_wal_flush) {
+      ASSERT_FALSE(res.ok());
+    }
+  }
+  // Close before mock_env destruct.
+  Close();
+}
+
 INSTANTIATE_TEST_CASE_P(DBWriteTestInstance, DBWriteTest,
                        testing::Values(DBTestBase::kDefault,
                                        DBTestBase::kConcurrentWALWrites,
@@ -46,6 +46,8 @@ EntryType GetEntryType(ValueType value_type) {
      return kEntrySingleDelete;
    case kTypeMerge:
      return kEntryMerge;
+    case kTypeRangeDeletion:
+      return kEntryRangeDeletion;
    default:
      return kEntryOther;
  }
@@ -106,45 +108,6 @@ const char* InternalKeyComparator::Name() const {
  return name_.c_str();
 }

-int InternalKeyComparator::Compare(const Slice& akey, const Slice& bkey) const {
-  // Order by:
-  //    increasing user key (according to user-supplied comparator)
-  //    decreasing sequence number
-  //    decreasing type (though sequence# should be enough to disambiguate)
-  int r = user_comparator_->Compare(ExtractUserKey(akey), ExtractUserKey(bkey));
-  PERF_COUNTER_ADD(user_key_comparison_count, 1);
-  if (r == 0) {
-    const uint64_t anum = DecodeFixed64(akey.data() + akey.size() - 8);
-    const uint64_t bnum = DecodeFixed64(bkey.data() + bkey.size() - 8);
-    if (anum > bnum) {
-      r = -1;
-    } else if (anum < bnum) {
-      r = +1;
-    }
-  }
-  return r;
-}
-
-int InternalKeyComparator::CompareKeySeq(const Slice& akey,
-                                         const Slice& bkey) const {
-  // Order by:
-  //    increasing user key (according to user-supplied comparator)
-  //    decreasing sequence number
-  int r = user_comparator_->Compare(ExtractUserKey(akey), ExtractUserKey(bkey));
-  PERF_COUNTER_ADD(user_key_comparison_count, 1);
-  if (r == 0) {
-    // Shift the number to exclude the last byte which contains the value type
-    const uint64_t anum = DecodeFixed64(akey.data() + akey.size() - 8) >> 8;
-    const uint64_t bnum = DecodeFixed64(bkey.data() + bkey.size() - 8) >> 8;
-    if (anum > bnum) {
-      r = -1;
-    } else if (anum < bnum) {
-      r = +1;
-    }
-  }
-  return r;
-}
-
 int InternalKeyComparator::Compare(const ParsedInternalKey& a,
                                   const ParsedInternalKey& b) const {
  // Order by:
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string>
 #include <utility>
+#include "monitoring/perf_context_imp.h"
 #include "rocksdb/comparator.h"
 #include "rocksdb/db.h"
 #include "rocksdb/filter_policy.h"
@@ -607,4 +608,46 @@ struct RangeTombstone {
  }
 };

+inline
+int InternalKeyComparator::Compare(const Slice& akey, const Slice& bkey) const {
+  // Order by:
+  //    increasing user key (according to user-supplied comparator)
+  //    decreasing sequence number
+  //    decreasing type (though sequence# should be enough to disambiguate)
+  int r = user_comparator_->Compare(ExtractUserKey(akey), ExtractUserKey(bkey));
+  PERF_COUNTER_ADD(user_key_comparison_count, 1);
+  if (r == 0) {
+    const uint64_t anum = DecodeFixed64(akey.data() + akey.size() - 8);
+    const uint64_t bnum = DecodeFixed64(bkey.data() + bkey.size() - 8);
+    if (anum > bnum) {
+      r = -1;
+    } else if (anum < bnum) {
+      r = +1;
+    }
+  }
+  return r;
+}
+
+inline
+int InternalKeyComparator::CompareKeySeq(const Slice& akey,
+                                         const Slice& bkey) const {
+  // Order by:
+  //    increasing user key (according to user-supplied comparator)
+  //    decreasing sequence number
+  int r = user_comparator_->Compare(ExtractUserKey(akey), ExtractUserKey(bkey));
+  PERF_COUNTER_ADD(user_key_comparison_count, 1);
+  if (r == 0) {
+    // Shift the number to exclude the last byte which contains the value type
+    const uint64_t anum = DecodeFixed64(akey.data() + akey.size() - 8) >> 8;
+    const uint64_t bnum = DecodeFixed64(bkey.data() + bkey.size() - 8) >> 8;
+    if (anum > bnum) {
+      r = -1;
+    } else if (anum < bnum) {
+      r = +1;
+    }
+  }
+  return r;
+}
+
+
 }  // namespace rocksdb
@@ -8,7 +8,7 @@
 namespace rocksdb {

 namespace {
-template<class T>
+template <class T>
 inline T SafeDivide(T a, T b) {
  return b == 0 ? 0 : a / b;
 }
@@ -17,7 +17,8 @@ inline T SafeDivide(T a, T b) {
 void EventHelpers::AppendCurrentTime(JSONWriter* jwriter) {
  *jwriter << "time_micros"
           << std::chrono::duration_cast<std::chrono::microseconds>(
-                  std::chrono::system_clock::now().time_since_epoch()).count();
+                  std::chrono::system_clock::now().time_since_epoch())
+                  .count();
 }

 #ifndef ROCKSDB_LITE
@@ -52,6 +53,11 @@ void EventHelpers::NotifyOnBackgroundError(
    listener->OnBackgroundError(reason, bg_error);
  }
  db_mutex->Lock();
+#else
+  (void)listeners;
+  (void)reason;
+  (void)bg_error;
+  (void)db_mutex;
 #endif  // ROCKSDB_LITE
 }

@@ -117,20 +123,25 @@ void EventHelpers::LogAndNotifyTableFileCreationFinished(
  for (auto& listener : listeners) {
    listener->OnTableFileCreated(info);
  }
+#else
+  (void)listeners;
+  (void)db_name;
+  (void)cf_name;
+  (void)file_path;
+  (void)reason;
 #endif  // !ROCKSDB_LITE
 }

 void EventHelpers::LogAndNotifyTableFileDeletion(
-    EventLogger* event_logger, int job_id,
-    uint64_t file_number, const std::string& file_path,
-    const Status& status, const std::string& dbname,
+    EventLogger* event_logger, int job_id, uint64_t file_number,
+    const std::string& file_path, const Status& status,
+    const std::string& dbname,
    const std::vector<std::shared_ptr<EventListener>>& listeners) {
-
  JSONWriter jwriter;
  AppendCurrentTime(&jwriter);

-  jwriter << "job" << job_id
-          << "event" << "table_file_deletion"
+  jwriter << "job" << job_id << "event"
+          << "table_file_deletion"
          << "file_number" << file_number;
  if (!status.ok()) {
    jwriter << "status" << status.ToString();
@@ -149,6 +160,10 @@ void EventHelpers::LogAndNotifyTableFileDeletion(
  for (auto& listener : listeners) {
    listener->OnTableFileDeleted(info);
  }
+#else
+  (void)file_path;
+  (void)dbname;
+  (void)listeners;
 #endif  // !ROCKSDB_LITE
 }

@@ -30,12 +30,13 @@ Status PromoteL0(DB* db, ColumnFamilyHandle* column_family, int target_level) {

 #else  // ROCKSDB_LITE

-Status SuggestCompactRange(DB* db, ColumnFamilyHandle* column_family,
-                           const Slice* begin, const Slice* end) {
+Status SuggestCompactRange(DB* /*db*/, ColumnFamilyHandle* /*column_family*/,
+                           const Slice* /*begin*/, const Slice* /*end*/) {
  return Status::NotSupported("Not supported in RocksDB LITE");
 }

-Status PromoteL0(DB* db, ColumnFamilyHandle* column_family, int target_level) {
+Status PromoteL0(DB* /*db*/, ColumnFamilyHandle* /*column_family*/,
+                 int /*target_level*/) {
  return Status::NotSupported("Not supported in RocksDB LITE");
 }

@@ -29,13 +29,13 @@
 namespace rocksdb {

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

  // Read the information of files we are ingesting
  for (const std::string& file_path : external_files_paths) {
    IngestedFileInfo file_to_ingest;
-    status = GetIngestedFileInfo(file_path, &file_to_ingest);
+    status = GetIngestedFileInfo(file_path, &file_to_ingest, sv);
    if (!status.ok()) {
      return status;
    }
@@ -94,7 +94,8 @@ Status ExternalSstFileIngestionJob::Prepare(

    const std::string path_outside_db = f.external_file_path;
    const std::string path_inside_db =
-        TableFileName(db_options_.db_paths, f.fd.GetNumber(), f.fd.GetPathId());
+        TableFileName(cfd_->ioptions()->cf_paths, f.fd.GetNumber(),
+                      f.fd.GetPathId());

    if (ingestion_options_.move_files) {
      status = env_->LinkFile(path_outside_db, path_inside_db);
@@ -102,12 +103,16 @@ Status ExternalSstFileIngestionJob::Prepare(
        // Original file is on a different FS, use copy instead of hard linking
        status = CopyFile(env_, path_outside_db, path_inside_db, 0,
                          db_options_.use_fsync);
+        f.copy_file = true;
+      } else {
+        f.copy_file = false;
      }
    } else {
      status = CopyFile(env_, path_outside_db, path_inside_db, 0,
                        db_options_.use_fsync);
+      f.copy_file = true;
    }
-    TEST_SYNC_POINT("DBImpl::AddFile:FileCopied");
+    TEST_SYNC_POINT("ExternalSstFileIngestionJob::Prepare:FileAdded");
    if (!status.ok()) {
      break;
    }
@@ -117,7 +122,7 @@ Status ExternalSstFileIngestionJob::Prepare(
  if (!status.ok()) {
    // We failed, remove all files that we copied into the db
    for (IngestedFileInfo& f : files_to_ingest_) {
-      if (f.internal_file_path == "") {
+      if (f.internal_file_path.empty()) {
        break;
      }
      Status s = env_->DeleteFile(f.internal_file_path);
@@ -217,9 +222,17 @@ void ExternalSstFileIngestionJob::UpdateStats() {
  uint64_t total_l0_files = 0;
  uint64_t total_time = env_->NowMicros() - job_start_time_;
  for (IngestedFileInfo& f : files_to_ingest_) {
-    InternalStats::CompactionStats stats(1);
+    InternalStats::CompactionStats stats(CompactionReason::kExternalSstIngestion, 1);
    stats.micros = total_time;
-    stats.bytes_written = f.fd.GetFileSize();
+    // If actual copy occured for this file, then we need to count the file
+    // size as the actual bytes written. If the file was linked, then we ignore
+    // the bytes written for file metadata.
+    // TODO (yanqin) maybe account for file metadata bytes for exact accuracy?
+    if (f.copy_file) {
+      stats.bytes_written = f.fd.GetFileSize();
+    } else {
+      stats.bytes_moved = f.fd.GetFileSize();
+    }
    stats.num_output_files = 1;
    cfd_->internal_stats()->AddCompactionStats(f.picked_level, stats);
    cfd_->internal_stats()->AddCFStats(InternalStats::BYTES_INGESTED_ADD_FILE,
@@ -271,7 +284,8 @@ void ExternalSstFileIngestionJob::Cleanup(const Status& status) {
 }

 Status ExternalSstFileIngestionJob::GetIngestedFileInfo(
-    const std::string& external_file, IngestedFileInfo* file_to_ingest) {
+    const std::string& external_file, IngestedFileInfo* file_to_ingest,
+    SuperVersion* sv) {
  file_to_ingest->external_file_path = external_file;

  // Get external file size
@@ -293,8 +307,9 @@ Status ExternalSstFileIngestionJob::GetIngestedFileInfo(
                                                   external_file));

  status = cfd_->ioptions()->table_factory->NewTableReader(
-      TableReaderOptions(*cfd_->ioptions(), env_options_,
-                         cfd_->internal_comparator()),
+      TableReaderOptions(*cfd_->ioptions(),
+                         sv->mutable_cf_options.prefix_extractor.get(),
+                         env_options_, cfd_->internal_comparator()),
      std::move(sst_file_reader), file_to_ingest->file_size, &table_reader);
  if (!status.ok()) {
    return status;
@@ -350,7 +365,8 @@ Status ExternalSstFileIngestionJob::GetIngestedFileInfo(
  // We need to disable fill_cache so that we read from the file without
  // updating the block cache.
  ro.fill_cache = false;
-  std::unique_ptr<InternalIterator> iter(table_reader->NewIterator(ro));
+  std::unique_ptr<InternalIterator> iter(table_reader->NewIterator(
+      ro, sv->mutable_cf_options.prefix_extractor.get()));

  // Get first (smallest) key from file
  iter->SeekToFirst();
@@ -46,11 +46,18 @@ struct IngestedFileInfo {
  // FileDescriptor for the file inside the DB
  FileDescriptor fd;
  // file path that we picked for file inside the DB
-  std::string internal_file_path = "";
+  std::string internal_file_path;
  // Global sequence number that we picked for the file inside the DB
  SequenceNumber assigned_seqno = 0;
  // Level inside the DB we picked for the external file.
  int picked_level = 0;
+  // Whether to copy or link the external sst file. copy_file will be set to
+  // false if ingestion_options.move_files is true and underlying FS
+  // supports link operation. Need to provide a default value to make the
+  // undefined-behavior sanity check of llvm happy. Since
+  // ingestion_options.move_files is false by default, thus copy_file is true
+  // by default.
+  bool copy_file = true;

  InternalKey smallest_internal_key() const {
    return InternalKey(smallest_user_key, assigned_seqno,
@@ -79,7 +86,8 @@ class ExternalSstFileIngestionJob {
        job_start_time_(env_->NowMicros()) {}

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

  // Check if we need to flush the memtable before running the ingestion job
  // This will be true if the files we are ingesting are overlapping with any
@@ -112,7 +120,8 @@ class ExternalSstFileIngestionJob {
  // Open the external file and populate `file_to_ingest` with all the
  // external information we need to ingest this file.
  Status GetIngestedFileInfo(const std::string& external_file,
-                             IngestedFileInfo* file_to_ingest);
+                             IngestedFileInfo* file_to_ingest,
+                             SuperVersion* sv);

  // Assign `file_to_ingest` the appropriate sequence number and  the lowest
  // possible level that it can be ingested to according to compaction_style.
@@ -689,7 +689,7 @@ TEST_F(ExternalSSTFileTest, PurgeObsoleteFilesBug) {
  DestroyAndReopen(options);

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::AddFile:FileCopied", [&](void* arg) {
+      "ExternalSstFileIngestionJob::Prepare:FileAdded", [&](void* /* arg */) {
        ASSERT_OK(Put("aaa", "bbb"));
        ASSERT_OK(Flush());
        ASSERT_OK(Put("aaa", "xxx"));
@@ -1128,7 +1128,7 @@ TEST_F(ExternalSSTFileTest, PickedLevelBug) {
  std::atomic<bool> bg_compact_started(false);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BackgroundCompaction:Start",
-      [&](void* arg) { bg_compact_started.store(true); });
+      [&](void* /*arg*/) { bg_compact_started.store(true); });

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

@@ -1409,12 +1409,16 @@ TEST_F(ExternalSSTFileTest, AddFileTrivialMoveBug) {
  ASSERT_OK(GenerateAndAddExternalFile(options, {22, 23}, 6));  // L2

  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "CompactionJob::Run():Start", [&](void* arg) {
+      "CompactionJob::Run():Start", [&](void* /*arg*/) {
        // fit in L3 but will overlap with compaction so will be added
        // to L2 but a compaction will trivially move it to L3
        // and break LSM consistency
-        ASSERT_OK(dbfull()->SetOptions({{"max_bytes_for_level_base", "1"}}));
-        ASSERT_OK(GenerateAndAddExternalFile(options, {15, 16}, 7));
+        static std::atomic<bool> called = {false};
+        if (!called) {
+          called = true;
+          ASSERT_OK(dbfull()->SetOptions({{"max_bytes_for_level_base", "1"}}));
+          ASSERT_OK(GenerateAndAddExternalFile(options, {15, 16}, 7));
+        }
      });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();

@@ -1797,6 +1801,56 @@ TEST_F(ExternalSSTFileTest, FileWithCFInfo) {
  ASSERT_OK(db_->IngestExternalFile(handles_[2], {unknown_sst}, ifo));
 }

+/*
+ * Test and verify the functionality of ingestion_options.move_files.
+ */
+TEST_F(ExternalSSTFileTest, LinkExternalSst) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  DestroyAndReopen(options);
+  const int kNumKeys = 10000;
+
+  std::string file_path = sst_files_dir_ + "file1.sst";
+  // Create SstFileWriter for default column family
+  SstFileWriter sst_file_writer(EnvOptions(), options);
+  ASSERT_OK(sst_file_writer.Open(file_path));
+  for (int i = 0; i < kNumKeys; i++) {
+    ASSERT_OK(sst_file_writer.Put(Key(i), Key(i) + "_value"));
+  }
+  ASSERT_OK(sst_file_writer.Finish());
+  uint64_t file_size = 0;
+  ASSERT_OK(env_->GetFileSize(file_path, &file_size));
+
+  IngestExternalFileOptions ifo;
+  ifo.move_files = true;
+  ASSERT_OK(db_->IngestExternalFile({file_path}, ifo));
+
+  ColumnFamilyHandleImpl* cfh =
+      static_cast<ColumnFamilyHandleImpl*>(dbfull()->DefaultColumnFamily());
+  ColumnFamilyData* cfd = cfh->cfd();
+  const InternalStats* internal_stats_ptr = cfd->internal_stats();
+  const std::vector<InternalStats::CompactionStats>& comp_stats =
+      internal_stats_ptr->TEST_GetCompactionStats();
+  uint64_t bytes_copied = 0;
+  uint64_t bytes_moved = 0;
+  for (const auto& stats : comp_stats) {
+    bytes_copied += stats.bytes_written;
+    bytes_moved += stats.bytes_moved;
+  }
+  // If bytes_moved > 0, it means external sst resides on the same FS
+  // supporting hard link operation. Therefore,
+  // 0 bytes should be copied, and the bytes_moved == file_size.
+  // Otherwise, FS does not support hard link, or external sst file resides on
+  // a different file system, then the bytes_copied should be equal to
+  // file_size.
+  if (bytes_moved > 0) {
+    ASSERT_EQ(0, bytes_copied);
+    ASSERT_EQ(file_size, bytes_moved);
+  } else {
+    ASSERT_EQ(file_size, bytes_copied);
+  }
+}
+
 class TestIngestExternalFileListener : public EventListener {
 public:
  void OnExternalFileIngested(DB* /*db*/,
@@ -34,19 +34,22 @@ static const int kValueSize = 1000;
 static const int kMaxNumValues = 2000;
 static const size_t kNumIterations = 3;

-class FaultInjectionTest : public testing::Test,
-                           public testing::WithParamInterface<bool> {
+enum FaultInjectionOptionConfig {
+  kDefault,
+  kDifferentDataDir,
+  kWalDir,
+  kSyncWal,
+  kWalDirSyncWal,
+  kMultiLevels,
+  kEnd,
+};
+class FaultInjectionTest
+    : public testing::Test,
+      public testing::WithParamInterface<std::tuple<
+          bool, FaultInjectionOptionConfig, FaultInjectionOptionConfig>> {
 protected:
-  enum OptionConfig {
-    kDefault,
-    kDifferentDataDir,
-    kWalDir,
-    kSyncWal,
-    kWalDirSyncWal,
-    kMultiLevels,
-    kEnd,
-  };
  int option_config_;
+  int non_inclusive_end_range_;  // kEnd or equivalent to that
  // When need to make sure data is persistent, sync WAL
  bool sync_use_wal_;
  // When need to make sure data is persistent, call DB::CompactRange()
@@ -72,13 +75,13 @@ class FaultInjectionTest : public testing::Test,
  DB* db_;

  FaultInjectionTest()
-      : option_config_(kDefault),
+      : option_config_(std::get<1>(GetParam())),
+        non_inclusive_end_range_(std::get<2>(GetParam())),
        sync_use_wal_(false),
        sync_use_compact_(true),
        base_env_(nullptr),
        env_(nullptr),
-        db_(nullptr) {
-  }
+        db_(nullptr) {}

  ~FaultInjectionTest() {
    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
@@ -87,7 +90,7 @@ class FaultInjectionTest : public testing::Test,

  bool ChangeOptions() {
    option_config_++;
-    if (option_config_ >= kEnd) {
+    if (option_config_ >= non_inclusive_end_range_) {
      return false;
    } else {
      if (option_config_ == kMultiLevels) {
@@ -166,7 +169,7 @@ class FaultInjectionTest : public testing::Test,
  }

  void SetUp() override {
-    sequential_order_ = GetParam();
+    sequential_order_ = std::get<0>(GetParam());
    ASSERT_OK(NewDB());
  }

@@ -343,7 +346,9 @@ class FaultInjectionTest : public testing::Test,
  }
 };

-TEST_P(FaultInjectionTest, FaultTest) {
+class FaultInjectionTestSplitted : public FaultInjectionTest {};
+
+TEST_P(FaultInjectionTestSplitted, FaultTest) {
  do {
    Random rnd(301);

@@ -456,10 +461,10 @@ TEST_P(FaultInjectionTest, UninstalledCompaction) {

  std::atomic<bool> opened(false);
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
-      "DBImpl::Open:Opened", [&](void* arg) { opened.store(true); });
+      "DBImpl::Open:Opened", [&](void* /*arg*/) { opened.store(true); });
  rocksdb::SyncPoint::GetInstance()->SetCallBack(
      "DBImpl::BGWorkCompaction",
-      [&](void* arg) { ASSERT_TRUE(opened.load()); });
+      [&](void* /*arg*/) { ASSERT_TRUE(opened.load()); });
  rocksdb::SyncPoint::GetInstance()->EnableProcessing();
  ASSERT_OK(OpenDB());
  ASSERT_OK(Verify(0, kNumKeys, FaultInjectionTest::kValExpectFound));
@@ -530,7 +535,17 @@ TEST_P(FaultInjectionTest, WriteBatchWalTerminationTest) {
  ASSERT_EQ(db_->Get(ro, "boys", &val), Status::NotFound());
 }

-INSTANTIATE_TEST_CASE_P(FaultTest, FaultInjectionTest, ::testing::Bool());
+INSTANTIATE_TEST_CASE_P(
+    FaultTest, FaultInjectionTest,
+    ::testing::Values(std::make_tuple(false, kDefault, kEnd),
+                      std::make_tuple(true, kDefault, kEnd)));
+
+INSTANTIATE_TEST_CASE_P(
+    FaultTest, FaultInjectionTestSplitted,
+    ::testing::Values(std::make_tuple(false, kDefault, kSyncWal),
+                      std::make_tuple(true, kDefault, kSyncWal),
+                      std::make_tuple(false, kSyncWal, kEnd),
+                      std::make_tuple(true, kSyncWal, kEnd)));

 }  // namespace rocksdb

@@ -56,8 +56,8 @@ namespace rocksdb {

 const char* GetFlushReasonString (FlushReason flush_reason) {
  switch (flush_reason) {
-    case FlushReason::kUnknown:
-      return "Unknown";
+    case FlushReason::kOthers:
+      return "Other Reasons";
    case FlushReason::kGetLiveFiles:
      return "Get Live Files";
    case FlushReason::kShutDown:
@@ -72,8 +72,12 @@ const char* GetFlushReasonString (FlushReason flush_reason) {
      return "Write Buffer Full";
    case FlushReason::kTest:
      return "Test";
-    case FlushReason::kSuperVersionChange:
-      return "SuperVersion Change";
+    case FlushReason::kDeleteFiles:
+      return "Delete Files";
+    case FlushReason::kAutoCompaction:
+      return "Auto Compaction";
+    case FlushReason::kManualFlush:
+      return "Manual Flush";
    default:
      return "Invalid";
  }
@@ -181,7 +185,8 @@ void FlushJob::PickMemTable() {
  base_->Ref();  // it is likely that we do not need this reference
 }

-Status FlushJob::Run(FileMetaData* file_meta) {
+Status FlushJob::Run(LogsWithPrepTracker* prep_tracker,
+                     FileMetaData* file_meta) {
  db_mutex_->AssertHeld();
  assert(pick_memtable_called);
  AutoThreadOperationStageUpdater stage_run(
@@ -222,7 +227,7 @@ Status FlushJob::Run(FileMetaData* file_meta) {
    TEST_SYNC_POINT("FlushJob::InstallResults");
    // Replace immutable memtable with the generated Table
    s = cfd_->imm()->InstallMemtableFlushResults(
-        cfd_, mutable_cf_options_, mems_, versions_, db_mutex_,
+        cfd_, mutable_cf_options_, mems_, prep_tracker, versions_, db_mutex_,
        meta_.fd.GetNumber(), &job_context_->memtables_to_free, db_directory_,
        log_buffer_);
  }
@@ -388,7 +393,7 @@ Status FlushJob::WriteLevel0Table() {
  }

  // Note that here we treat flush as level 0 compaction in internal stats
-  InternalStats::CompactionStats stats(1);
+  InternalStats::CompactionStats stats(CompactionReason::kFlush, 1);
  stats.micros = db_options_.env->NowMicros() - start_micros;
  stats.bytes_written = meta_.fd.GetFileSize();
  MeasureTime(stats_, FLUSH_TIME, stats.micros);
@@ -22,6 +22,7 @@
 #include "db/internal_stats.h"
 #include "db/job_context.h"
 #include "db/log_writer.h"
+#include "db/logs_with_prep_tracker.h"
 #include "db/memtable_list.h"
 #include "db/snapshot_impl.h"
 #include "db/version_edit.h"
@@ -42,6 +43,7 @@

 namespace rocksdb {

+class DBImpl;
 class MemTable;
 class SnapshotChecker;
 class TableCache;
@@ -71,7 +73,8 @@ class FlushJob {
  // Require db_mutex held.
  // Once PickMemTable() is called, either Run() or Cancel() has to be called.
  void PickMemTable();
-  Status Run(FileMetaData* file_meta = nullptr);
+  Status Run(LogsWithPrepTracker* prep_tracker = nullptr,
+             FileMetaData* file_meta = nullptr);
  void Cancel();
  TableProperties GetTableProperties() const { return table_properties_; }

@@ -150,7 +150,7 @@ TEST_F(FlushJobTest, NonEmpty) {
  FileMetaData fd;
  mutex_.Lock();
  flush_job.PickMemTable();
-  ASSERT_OK(flush_job.Run(&fd));
+  ASSERT_OK(flush_job.Run(nullptr, &fd));
  mutex_.Unlock();
  db_options_.statistics->histogramData(FLUSH_TIME, &hist);
  ASSERT_GT(hist.average, 0.0);
@@ -27,20 +27,22 @@ namespace rocksdb {
 // Usage:
 //     ForwardLevelIterator iter;
 //     iter.SetFileIndex(file_index);
-//     iter.Seek(target);
+//     iter.Seek(target); // or iter.SeekToFirst();
 //     iter.Next()
 class ForwardLevelIterator : public InternalIterator {
 public:
  ForwardLevelIterator(const ColumnFamilyData* const cfd,
                       const ReadOptions& read_options,
-                       const std::vector<FileMetaData*>& files)
+                       const std::vector<FileMetaData*>& files,
+                       const SliceTransform* prefix_extractor)
      : cfd_(cfd),
        read_options_(read_options),
        files_(files),
        valid_(false),
        file_index_(std::numeric_limits<uint32_t>::max()),
        file_iter_(nullptr),
-        pinned_iters_mgr_(nullptr) {}
+        pinned_iters_mgr_(nullptr),
+        prefix_extractor_(prefix_extractor) {}

  ~ForwardLevelIterator() {
    // Reset current pointer
@@ -53,11 +55,11 @@ class ForwardLevelIterator : public InternalIterator {

  void SetFileIndex(uint32_t file_index) {
    assert(file_index < files_.size());
+    status_ = Status::OK();
    if (file_index != file_index_) {
      file_index_ = file_index;
      Reset();
    }
-    valid_ = false;
  }
  void Reset() {
    assert(file_index_ < files_.size());
@@ -75,12 +77,12 @@ class ForwardLevelIterator : public InternalIterator {
        read_options_, *(cfd_->soptions()), cfd_->internal_comparator(),
        files_[file_index_]->fd,
        read_options_.ignore_range_deletions ? nullptr : &range_del_agg,
-        nullptr /* table_reader_ptr */, nullptr, false);
+        prefix_extractor_, nullptr /* table_reader_ptr */, nullptr, false);
    file_iter_->SetPinnedItersMgr(pinned_iters_mgr_);
+    valid_ = false;
    if (!range_del_agg.IsEmpty()) {
      status_ = Status::NotSupported(
          "Range tombstones unsupported with ForwardIterator");
-      valid_ = false;
    }
  }
  void SeekToLast() override {
@@ -95,12 +97,27 @@ class ForwardLevelIterator : public InternalIterator {
    return valid_;
  }
  void SeekToFirst() override {
-    SetFileIndex(0);
+    assert(file_iter_ != nullptr);
+    if (!status_.ok()) {
+      assert(!valid_);
+      return;
+    }
    file_iter_->SeekToFirst();
    valid_ = file_iter_->Valid();
  }
  void Seek(const Slice& internal_key) override {
    assert(file_iter_ != nullptr);
+
+    // This deviates from the usual convention for InternalIterator::Seek() in
+    // that it doesn't discard pre-existing error status. That's because this
+    // Seek() is only supposed to be called immediately after SetFileIndex()
+    // (which discards pre-existing error status), and SetFileIndex() may set
+    // an error status, which we shouldn't discard.
+    if (!status_.ok()) {
+      assert(!valid_);
+      return;
+    }
+
    file_iter_->Seek(internal_key);
    valid_ = file_iter_->Valid();
  }
@@ -112,8 +129,12 @@ class ForwardLevelIterator : public InternalIterator {
    assert(valid_);
    file_iter_->Next();
    for (;;) {
-      if (file_iter_->status().IsIncomplete() || file_iter_->Valid()) {
-        valid_ = !file_iter_->status().IsIncomplete();
+      valid_ = file_iter_->Valid();
+      if (!file_iter_->status().ok()) {
+        assert(!valid_);
+        return;
+      }
+      if (valid_) {
        return;
      }
      if (file_index_ + 1 >= files_.size()) {
@@ -121,6 +142,10 @@ class ForwardLevelIterator : public InternalIterator {
        return;
      }
      SetFileIndex(file_index_ + 1);
+      if (!status_.ok()) {
+        assert(!valid_);
+        return;
+      }
      file_iter_->SeekToFirst();
    }
  }
@@ -135,7 +160,7 @@ class ForwardLevelIterator : public InternalIterator {
  Status status() const override {
    if (!status_.ok()) {
      return status_;
-    } else if (file_iter_ && !file_iter_->status().ok()) {
+    } else if (file_iter_) {
      return file_iter_->status();
    }
    return Status::OK();
@@ -165,6 +190,7 @@ class ForwardLevelIterator : public InternalIterator {
  Status status_;
  InternalIterator* file_iter_;
  PinnedIteratorsManager* pinned_iters_mgr_;
+  const SliceTransform* prefix_extractor_;
 };

 ForwardIterator::ForwardIterator(DBImpl* db, const ReadOptions& read_options,
@@ -173,7 +199,7 @@ ForwardIterator::ForwardIterator(DBImpl* db, const ReadOptions& read_options,
    : db_(db),
      read_options_(read_options),
      cfd_(cfd),
-      prefix_extractor_(cfd->ioptions()->prefix_extractor),
+      prefix_extractor_(current_sv->mutable_cf_options.prefix_extractor.get()),
      user_comparator_(cfd->user_comparator()),
      immutable_min_heap_(MinIterComparator(&cfd_->internal_comparator())),
      sv_(current_sv),
@@ -299,9 +325,6 @@ bool ForwardIterator::IsOverUpperBound(const Slice& internal_key) const {
 }

 void ForwardIterator::Seek(const Slice& internal_key) {
-  if (IsOverUpperBound(internal_key)) {
-    valid_ = false;
-  }
  if (sv_ == nullptr) {
    RebuildIterators(true);
  } else if (sv_->version_number != cfd_->GetSuperVersionNumber()) {
@@ -605,13 +628,16 @@ void ForwardIterator::RebuildIterators(bool refresh_sv) {
    if ((read_options_.iterate_upper_bound != nullptr) &&
        cfd_->internal_comparator().user_comparator()->Compare(
            l0->smallest.user_key(), *read_options_.iterate_upper_bound) > 0) {
-      has_iter_trimmed_for_upper_bound_ = true;
+      // No need to set has_iter_trimmed_for_upper_bound_: this ForwardIterator
+      // will never be interested in files with smallest key above
+      // iterate_upper_bound, since iterate_upper_bound can't be changed.
      l0_iters_.push_back(nullptr);
      continue;
    }
    l0_iters_.push_back(cfd_->table_cache()->NewIterator(
        read_options_, *cfd_->soptions(), cfd_->internal_comparator(), l0->fd,
-        read_options_.ignore_range_deletions ? nullptr : &range_del_agg));
+        read_options_.ignore_range_deletions ? nullptr : &range_del_agg,
+        sv_->mutable_cf_options.prefix_extractor.get()));
  }
  BuildLevelIterators(vstorage);
  current_ = nullptr;
@@ -681,7 +707,8 @@ void ForwardIterator::RenewIterators() {
    l0_iters_new.push_back(cfd_->table_cache()->NewIterator(
        read_options_, *cfd_->soptions(), cfd_->internal_comparator(),
        l0_files_new[inew]->fd,
-        read_options_.ignore_range_deletions ? nullptr : &range_del_agg));
+        read_options_.ignore_range_deletions ? nullptr : &range_del_agg,
+        svnew->mutable_cf_options.prefix_extractor.get()));
  }

  for (auto* f : l0_iters_) {
@@ -722,8 +749,9 @@ void ForwardIterator::BuildLevelIterators(const VersionStorageInfo* vstorage) {
        has_iter_trimmed_for_upper_bound_ = true;
      }
    } else {
-      level_iters_.push_back(
-          new ForwardLevelIterator(cfd_, read_options_, level_files));
+      level_iters_.push_back(new ForwardLevelIterator(
+          cfd_, read_options_, level_files,
+          sv_->mutable_cf_options.prefix_extractor.get()));
    }
  }
 }
@@ -738,7 +766,8 @@ void ForwardIterator::ResetIncompleteIterators() {
    DeleteIterator(l0_iters_[i]);
    l0_iters_[i] = cfd_->table_cache()->NewIterator(
        read_options_, *cfd_->soptions(), cfd_->internal_comparator(),
-        l0_files[i]->fd, nullptr /* range_del_agg */);
+        l0_files[i]->fd, nullptr /* range_del_agg */,
+        sv_->mutable_cf_options.prefix_extractor.get());
    l0_iters_[i]->SetPinnedItersMgr(pinned_iters_mgr_);
  }

@@ -773,7 +802,7 @@ void ForwardIterator::UpdateCurrent() {
      current_ = mutable_iter_;
    }
  }
-  valid_ = (current_ != nullptr);
+  valid_ = current_ != nullptr && immutable_status_.ok();
  if (!status_.ok()) {
    status_ = Status::OK();
  }
@@ -18,9 +18,10 @@
 #include <string>
 #include <utility>
 #include <vector>
-#include "db/column_family.h"

+#include "db/column_family.h"
 #include "db/db_impl.h"
+#include "table/block_based_table_factory.h"
 #include "util/string_util.h"

 namespace rocksdb {
@@ -86,8 +87,7 @@ void PrepareLevelStats(std::map<LevelStatType, double>* level_stats,
                       const InternalStats::CompactionStats& stats) {
  uint64_t bytes_read =
      stats.bytes_read_non_output_levels + stats.bytes_read_output_level;
-  int64_t bytes_new =
-      stats.bytes_written - stats.bytes_read_output_level;
+  int64_t bytes_new = stats.bytes_written - stats.bytes_read_output_level;
  double elapsed = (stats.micros + 1) / kMicrosInSec;

  (*level_stats)[LevelStatType::NUM_FILES] = num_files;
@@ -117,50 +117,50 @@ void PrepareLevelStats(std::map<LevelStatType, double>* level_stats,

 void PrintLevelStats(char* buf, size_t len, const std::string& name,
                     const std::map<LevelStatType, double>& stat_value) {
-  snprintf(buf, len,
-           "%4s "      /*  Level */
-           "%6d/%-3d " /*  Files */
-           "%8s "      /*  Size */
-           "%5.1f "    /*  Score */
-           "%8.1f "    /*  Read(GB) */
-           "%7.1f "    /*  Rn(GB) */
-           "%8.1f "    /*  Rnp1(GB) */
-           "%9.1f "    /*  Write(GB) */
-           "%8.1f "    /*  Wnew(GB) */
-           "%9.1f "    /*  Moved(GB) */
-           "%5.1f "    /*  W-Amp */
-           "%8.1f "    /*  Rd(MB/s) */
-           "%8.1f "    /*  Wr(MB/s) */
-           "%9.0f "    /*  Comp(sec) */
-           "%9d "      /*  Comp(cnt) */
-           "%8.3f "    /*  Avg(sec) */
-           "%7s "      /*  KeyIn */
-           "%6s\n",    /*  KeyDrop */
-           name.c_str(),
-           static_cast<int>(stat_value.at(LevelStatType::NUM_FILES)),
-           static_cast<int>(stat_value.at(LevelStatType::COMPACTED_FILES)),
-           BytesToHumanString(
-               static_cast<uint64_t>(stat_value.at(LevelStatType::SIZE_BYTES)))
-               .c_str(),
-           stat_value.at(LevelStatType::SCORE),
-           stat_value.at(LevelStatType::READ_GB),
-           stat_value.at(LevelStatType::RN_GB),
-           stat_value.at(LevelStatType::RNP1_GB),
-           stat_value.at(LevelStatType::WRITE_GB),
-           stat_value.at(LevelStatType::W_NEW_GB),
-           stat_value.at(LevelStatType::MOVED_GB),
-           stat_value.at(LevelStatType::WRITE_AMP),
-           stat_value.at(LevelStatType::READ_MBPS),
-           stat_value.at(LevelStatType::WRITE_MBPS),
-           stat_value.at(LevelStatType::COMP_SEC),
-           static_cast<int>(stat_value.at(LevelStatType::COMP_COUNT)),
-           stat_value.at(LevelStatType::AVG_SEC),
-           NumberToHumanString(
-               static_cast<std::int64_t>(stat_value.at(LevelStatType::KEY_IN)))
-               .c_str(),
-           NumberToHumanString(static_cast<std::int64_t>(
-                                   stat_value.at(LevelStatType::KEY_DROP)))
-               .c_str());
+  snprintf(
+      buf, len,
+      "%4s "      /*  Level */
+      "%6d/%-3d " /*  Files */
+      "%8s "      /*  Size */
+      "%5.1f "    /*  Score */
+      "%8.1f "    /*  Read(GB) */
+      "%7.1f "    /*  Rn(GB) */
+      "%8.1f "    /*  Rnp1(GB) */
+      "%9.1f "    /*  Write(GB) */
+      "%8.1f "    /*  Wnew(GB) */
+      "%9.1f "    /*  Moved(GB) */
+      "%5.1f "    /*  W-Amp */
+      "%8.1f "    /*  Rd(MB/s) */
+      "%8.1f "    /*  Wr(MB/s) */
+      "%9.0f "    /*  Comp(sec) */
+      "%9d "      /*  Comp(cnt) */
+      "%8.3f "    /*  Avg(sec) */
+      "%7s "      /*  KeyIn */
+      "%6s\n",    /*  KeyDrop */
+      name.c_str(), static_cast<int>(stat_value.at(LevelStatType::NUM_FILES)),
+      static_cast<int>(stat_value.at(LevelStatType::COMPACTED_FILES)),
+      BytesToHumanString(
+          static_cast<uint64_t>(stat_value.at(LevelStatType::SIZE_BYTES)))
+          .c_str(),
+      stat_value.at(LevelStatType::SCORE),
+      stat_value.at(LevelStatType::READ_GB),
+      stat_value.at(LevelStatType::RN_GB),
+      stat_value.at(LevelStatType::RNP1_GB),
+      stat_value.at(LevelStatType::WRITE_GB),
+      stat_value.at(LevelStatType::W_NEW_GB),
+      stat_value.at(LevelStatType::MOVED_GB),
+      stat_value.at(LevelStatType::WRITE_AMP),
+      stat_value.at(LevelStatType::READ_MBPS),
+      stat_value.at(LevelStatType::WRITE_MBPS),
+      stat_value.at(LevelStatType::COMP_SEC),
+      static_cast<int>(stat_value.at(LevelStatType::COMP_COUNT)),
+      stat_value.at(LevelStatType::AVG_SEC),
+      NumberToHumanString(
+          static_cast<std::int64_t>(stat_value.at(LevelStatType::KEY_IN)))
+          .c_str(),
+      NumberToHumanString(
+          static_cast<std::int64_t>(stat_value.at(LevelStatType::KEY_DROP)))
+          .c_str());
 }

 void PrintLevelStats(char* buf, size_t len, const std::string& name,
@@ -208,30 +208,30 @@ static const std::string mem_table_flush_pending = "mem-table-flush-pending";
 static const std::string compaction_pending = "compaction-pending";
 static const std::string background_errors = "background-errors";
 static const std::string cur_size_active_mem_table =
-                          "cur-size-active-mem-table";
+    "cur-size-active-mem-table";
 static const std::string cur_size_all_mem_tables = "cur-size-all-mem-tables";
 static const std::string size_all_mem_tables = "size-all-mem-tables";
 static const std::string num_entries_active_mem_table =
-                          "num-entries-active-mem-table";
+    "num-entries-active-mem-table";
 static const std::string num_entries_imm_mem_tables =
-                          "num-entries-imm-mem-tables";
+    "num-entries-imm-mem-tables";
 static const std::string num_deletes_active_mem_table =
-                          "num-deletes-active-mem-table";
+    "num-deletes-active-mem-table";
 static const std::string num_deletes_imm_mem_tables =
-                          "num-deletes-imm-mem-tables";
+    "num-deletes-imm-mem-tables";
 static const std::string estimate_num_keys = "estimate-num-keys";
 static const std::string estimate_table_readers_mem =
-                          "estimate-table-readers-mem";
+    "estimate-table-readers-mem";
 static const std::string is_file_deletions_enabled =
-                          "is-file-deletions-enabled";
+    "is-file-deletions-enabled";
 static const std::string num_snapshots = "num-snapshots";
 static const std::string oldest_snapshot_time = "oldest-snapshot-time";
 static const std::string num_live_versions = "num-live-versions";
 static const std::string current_version_number =
    "current-super-version-number";
 static const std::string estimate_live_data_size = "estimate-live-data-size";
-static const std::string min_log_number_to_keep = "min-log-number-to-keep";
-static const std::string base_level = "base-level";
+static const std::string min_log_number_to_keep_str = "min-log-number-to-keep";
+static const std::string base_level_str = "base-level";
 static const std::string total_sst_files_size = "total-sst-files-size";
 static const std::string live_sst_files_size = "live-sst-files-size";
 static const std::string estimate_pending_comp_bytes =
@@ -246,11 +246,14 @@ static const std::string actual_delayed_write_rate =
    "actual-delayed-write-rate";
 static const std::string is_write_stopped = "is-write-stopped";
 static const std::string estimate_oldest_key_time = "estimate-oldest-key-time";
+static const std::string block_cache_capacity = "block-cache-capacity";
+static const std::string block_cache_usage = "block-cache-usage";
+static const std::string block_cache_pinned_usage = "block-cache-pinned-usage";

 const std::string DB::Properties::kNumFilesAtLevelPrefix =
-                      rocksdb_prefix + num_files_at_level_prefix;
+    rocksdb_prefix + num_files_at_level_prefix;
 const std::string DB::Properties::kCompressionRatioAtLevelPrefix =
-                      rocksdb_prefix + compression_ratio_at_level_prefix;
+    rocksdb_prefix + compression_ratio_at_level_prefix;
 const std::string DB::Properties::kStats = rocksdb_prefix + allstats;
 const std::string DB::Properties::kSSTables = rocksdb_prefix + sstables;
 const std::string DB::Properties::kCFStats = rocksdb_prefix + cfstats;
@@ -261,56 +264,56 @@ const std::string DB::Properties::kCFFileHistogram =
 const std::string DB::Properties::kDBStats = rocksdb_prefix + dbstats;
 const std::string DB::Properties::kLevelStats = rocksdb_prefix + levelstats;
 const std::string DB::Properties::kNumImmutableMemTable =
-                      rocksdb_prefix + num_immutable_mem_table;
+    rocksdb_prefix + num_immutable_mem_table;
 const std::string DB::Properties::kNumImmutableMemTableFlushed =
    rocksdb_prefix + num_immutable_mem_table_flushed;
 const std::string DB::Properties::kMemTableFlushPending =
-                      rocksdb_prefix + mem_table_flush_pending;
+    rocksdb_prefix + mem_table_flush_pending;
 const std::string DB::Properties::kCompactionPending =
-                      rocksdb_prefix + compaction_pending;
+    rocksdb_prefix + compaction_pending;
 const std::string DB::Properties::kNumRunningCompactions =
    rocksdb_prefix + num_running_compactions;
 const std::string DB::Properties::kNumRunningFlushes =
    rocksdb_prefix + num_running_flushes;
 const std::string DB::Properties::kBackgroundErrors =
-                      rocksdb_prefix + background_errors;
+    rocksdb_prefix + background_errors;
 const std::string DB::Properties::kCurSizeActiveMemTable =
-                      rocksdb_prefix + cur_size_active_mem_table;
+    rocksdb_prefix + cur_size_active_mem_table;
 const std::string DB::Properties::kCurSizeAllMemTables =
    rocksdb_prefix + cur_size_all_mem_tables;
 const std::string DB::Properties::kSizeAllMemTables =
    rocksdb_prefix + size_all_mem_tables;
 const std::string DB::Properties::kNumEntriesActiveMemTable =
-                      rocksdb_prefix + num_entries_active_mem_table;
+    rocksdb_prefix + num_entries_active_mem_table;
 const std::string DB::Properties::kNumEntriesImmMemTables =
-                      rocksdb_prefix + num_entries_imm_mem_tables;
+    rocksdb_prefix + num_entries_imm_mem_tables;
 const std::string DB::Properties::kNumDeletesActiveMemTable =
-                      rocksdb_prefix + num_deletes_active_mem_table;
+    rocksdb_prefix + num_deletes_active_mem_table;
 const std::string DB::Properties::kNumDeletesImmMemTables =
-                      rocksdb_prefix + num_deletes_imm_mem_tables;
+    rocksdb_prefix + num_deletes_imm_mem_tables;
 const std::string DB::Properties::kEstimateNumKeys =
-                      rocksdb_prefix + estimate_num_keys;
+    rocksdb_prefix + estimate_num_keys;
 const std::string DB::Properties::kEstimateTableReadersMem =
-                      rocksdb_prefix + estimate_table_readers_mem;
+    rocksdb_prefix + estimate_table_readers_mem;
 const std::string DB::Properties::kIsFileDeletionsEnabled =
-                      rocksdb_prefix + is_file_deletions_enabled;
+    rocksdb_prefix + is_file_deletions_enabled;
 const std::string DB::Properties::kNumSnapshots =
-                      rocksdb_prefix + num_snapshots;
+    rocksdb_prefix + num_snapshots;
 const std::string DB::Properties::kOldestSnapshotTime =
-                      rocksdb_prefix + oldest_snapshot_time;
+    rocksdb_prefix + oldest_snapshot_time;
 const std::string DB::Properties::kNumLiveVersions =
-                      rocksdb_prefix + num_live_versions;
+    rocksdb_prefix + num_live_versions;
 const std::string DB::Properties::kCurrentSuperVersionNumber =
    rocksdb_prefix + current_version_number;
 const std::string DB::Properties::kEstimateLiveDataSize =
-                      rocksdb_prefix + estimate_live_data_size;
+    rocksdb_prefix + estimate_live_data_size;
 const std::string DB::Properties::kMinLogNumberToKeep =
-    rocksdb_prefix + min_log_number_to_keep;
+    rocksdb_prefix + min_log_number_to_keep_str;
 const std::string DB::Properties::kTotalSstFilesSize =
-                      rocksdb_prefix + total_sst_files_size;
+    rocksdb_prefix + total_sst_files_size;
 const std::string DB::Properties::kLiveSstFilesSize =
    rocksdb_prefix + live_sst_files_size;
-const std::string DB::Properties::kBaseLevel = rocksdb_prefix + base_level;
+const std::string DB::Properties::kBaseLevel = rocksdb_prefix + base_level_str;
 const std::string DB::Properties::kEstimatePendingCompactionBytes =
    rocksdb_prefix + estimate_pending_comp_bytes;
 const std::string DB::Properties::kAggregatedTableProperties =
@@ -323,6 +326,12 @@ const std::string DB::Properties::kIsWriteStopped =
    rocksdb_prefix + is_write_stopped;
 const std::string DB::Properties::kEstimateOldestKeyTime =
    rocksdb_prefix + estimate_oldest_key_time;
+const std::string DB::Properties::kBlockCacheCapacity =
+    rocksdb_prefix + block_cache_capacity;
+const std::string DB::Properties::kBlockCacheUsage =
+    rocksdb_prefix + block_cache_usage;
+const std::string DB::Properties::kBlockCachePinnedUsage =
+    rocksdb_prefix + block_cache_pinned_usage;

 const std::unordered_map<std::string, DBPropertyInfo>
    InternalStats::ppt_name_to_info = {
@@ -426,6 +435,13 @@ const std::unordered_map<std::string, DBPropertyInfo>
        {DB::Properties::kEstimateOldestKeyTime,
         {false, nullptr, &InternalStats::HandleEstimateOldestKeyTime,
          nullptr}},
+        {DB::Properties::kBlockCacheCapacity,
+         {false, nullptr, &InternalStats::HandleBlockCacheCapacity, nullptr}},
+        {DB::Properties::kBlockCacheUsage,
+         {false, nullptr, &InternalStats::HandleBlockCacheUsage, nullptr}},
+        {DB::Properties::kBlockCachePinnedUsage,
+         {false, nullptr, &InternalStats::HandleBlockCachePinnedUsage,
+          nullptr}},
 };

 const DBPropertyInfo* GetPropertyInfo(const Slice& property) {
@@ -831,6 +847,58 @@ bool InternalStats::HandleEstimateOldestKeyTime(uint64_t* value, DBImpl* /*db*/,
  return *value > 0 && *value < std::numeric_limits<uint64_t>::max();
 }

+bool InternalStats::HandleBlockCacheStat(Cache** block_cache) {
+  assert(block_cache != nullptr);
+  auto* table_factory = cfd_->ioptions()->table_factory;
+  assert(table_factory != nullptr);
+  if (BlockBasedTableFactory::kName != table_factory->Name()) {
+    return false;
+  }
+  auto* table_options =
+      reinterpret_cast<BlockBasedTableOptions*>(table_factory->GetOptions());
+  if (table_options == nullptr) {
+    return false;
+  }
+  *block_cache = table_options->block_cache.get();
+  if (table_options->no_block_cache || *block_cache == nullptr) {
+    return false;
+  }
+  return true;
+}
+
+bool InternalStats::HandleBlockCacheCapacity(uint64_t* value, DBImpl* /*db*/,
+                                             Version* /*version*/) {
+  Cache* block_cache;
+  bool ok = HandleBlockCacheStat(&block_cache);
+  if (!ok) {
+    return false;
+  }
+  *value = static_cast<uint64_t>(block_cache->GetCapacity());
+  return true;
+}
+
+bool InternalStats::HandleBlockCacheUsage(uint64_t* value, DBImpl* /*db*/,
+                                          Version* /*version*/) {
+  Cache* block_cache;
+  bool ok = HandleBlockCacheStat(&block_cache);
+  if (!ok) {
+    return false;
+  }
+  *value = static_cast<uint64_t>(block_cache->GetUsage());
+  return true;
+}
+
+bool InternalStats::HandleBlockCachePinnedUsage(uint64_t* value, DBImpl* /*db*/,
+                                                Version* /*version*/) {
+  Cache* block_cache;
+  bool ok = HandleBlockCacheStat(&block_cache);
+  if (!ok) {
+    return false;
+  }
+  *value = static_cast<uint64_t>(block_cache->GetPinnedUsage());
+  return true;
+}
+
 void InternalStats::DumpDBStats(std::string* value) {
  char buf[1000];
  // DB-level stats, only available from default column family
@@ -882,8 +950,7 @@ void InternalStats::DumpDBStats(std::string* value) {
  value->append(buf);
  // Stall
  AppendHumanMicros(write_stall_micros, human_micros, kHumanMicrosLen, true);
-  snprintf(buf, sizeof(buf),
-           "Cumulative stall: %s, %.1f percent\n",
+  snprintf(buf, sizeof(buf), "Cumulative stall: %s, %.1f percent\n",
           human_micros,
           // 10000 = divide by 1M to get secs, then multiply by 100 for pct
           write_stall_micros / 10000.0 / std::max(seconds_up, 0.001));
@@ -894,43 +961,40 @@ void InternalStats::DumpDBStats(std::string* value) {
  uint64_t interval_write_self = write_self - db_stats_snapshot_.write_self;
  uint64_t interval_num_keys_written =
      num_keys_written - db_stats_snapshot_.num_keys_written;
-  snprintf(buf, sizeof(buf),
-           "Interval writes: %s writes, %s keys, %s commit groups, "
-           "%.1f writes per commit group, ingest: %.2f MB, %.2f MB/s\n",
-           NumberToHumanString(
-               interval_write_other + interval_write_self).c_str(),
-           NumberToHumanString(interval_num_keys_written).c_str(),
-           NumberToHumanString(interval_write_self).c_str(),
-           static_cast<double>(interval_write_other + interval_write_self) /
-               (interval_write_self + 1),
-           (user_bytes_written - db_stats_snapshot_.ingest_bytes) / kMB,
-           (user_bytes_written - db_stats_snapshot_.ingest_bytes) / kMB /
-               std::max(interval_seconds_up, 0.001)),
-  value->append(buf);
+  snprintf(
+      buf, sizeof(buf),
+      "Interval writes: %s writes, %s keys, %s commit groups, "
+      "%.1f writes per commit group, ingest: %.2f MB, %.2f MB/s\n",
+      NumberToHumanString(interval_write_other + interval_write_self).c_str(),
+      NumberToHumanString(interval_num_keys_written).c_str(),
+      NumberToHumanString(interval_write_self).c_str(),
+      static_cast<double>(interval_write_other + interval_write_self) /
+          (interval_write_self + 1),
+      (user_bytes_written - db_stats_snapshot_.ingest_bytes) / kMB,
+      (user_bytes_written - db_stats_snapshot_.ingest_bytes) / kMB /
+          std::max(interval_seconds_up, 0.001)),
+      value->append(buf);

  uint64_t interval_write_with_wal =
      write_with_wal - db_stats_snapshot_.write_with_wal;
  uint64_t interval_wal_synced = wal_synced - db_stats_snapshot_.wal_synced;
  uint64_t interval_wal_bytes = wal_bytes - db_stats_snapshot_.wal_bytes;

-  snprintf(buf, sizeof(buf),
-           "Interval WAL: %s writes, %s syncs, "
-           "%.2f writes per sync, written: %.2f MB, %.2f MB/s\n",
-           NumberToHumanString(interval_write_with_wal).c_str(),
-           NumberToHumanString(interval_wal_synced).c_str(),
-           interval_write_with_wal /
-              static_cast<double>(interval_wal_synced + 1),
-           interval_wal_bytes / kGB,
-           interval_wal_bytes / kMB / std::max(interval_seconds_up, 0.001));
+  snprintf(
+      buf, sizeof(buf),
+      "Interval WAL: %s writes, %s syncs, "
+      "%.2f writes per sync, written: %.2f MB, %.2f MB/s\n",
+      NumberToHumanString(interval_write_with_wal).c_str(),
+      NumberToHumanString(interval_wal_synced).c_str(),
+      interval_write_with_wal / static_cast<double>(interval_wal_synced + 1),
+      interval_wal_bytes / kGB,
+      interval_wal_bytes / kMB / std::max(interval_seconds_up, 0.001));
  value->append(buf);

  // Stall
-  AppendHumanMicros(
-      write_stall_micros - db_stats_snapshot_.write_stall_micros,
-      human_micros, kHumanMicrosLen, true);
-  snprintf(buf, sizeof(buf),
-           "Interval stall: %s, %.1f percent\n",
-           human_micros,
+  AppendHumanMicros(write_stall_micros - db_stats_snapshot_.write_stall_micros,
+                    human_micros, kHumanMicrosLen, true);
+  snprintf(buf, sizeof(buf), "Interval stall: %s, %.1f percent\n", human_micros,
           // 10000 = divide by 1M to get secs, then multiply by 100 for pct
           (write_stall_micros - db_stats_snapshot_.write_stall_micros) /
               10000.0 / std::max(interval_seconds_up, 0.001));
@@ -956,8 +1020,8 @@ void InternalStats::DumpDBStats(std::string* value) {
 * and values represent uint64 encoded as strings.
 */
 void InternalStats::DumpCFMapStats(
-        std::map<std::string, std::string>* cf_stats) {
-  CompactionStats compaction_stats_sum(0);
+    std::map<std::string, std::string>* cf_stats) {
+  CompactionStats compaction_stats_sum;
  std::map<int, std::map<LevelStatType, double>> levels_stats;
  DumpCFMapStats(&levels_stats, &compaction_stats_sum);
  for (auto const& level_ent : levels_stats) {
@@ -1088,7 +1152,7 @@ void InternalStats::DumpCFStatsNoFileHistogram(std::string* value) {

  // Print stats for each level
  std::map<int, std::map<LevelStatType, double>> levels_stats;
-  CompactionStats compaction_stats_sum(0);
+  CompactionStats compaction_stats_sum;
  DumpCFMapStats(&levels_stats, &compaction_stats_sum);
  for (int l = 0; l < number_levels_; ++l) {
    if (levels_stats.find(l) != levels_stats.end()) {
@@ -1143,8 +1207,9 @@ void InternalStats::DumpCFStatsNoFileHistogram(std::string* value) {

  uint64_t interval_ingest_files_addfile =
      ingest_files_addfile - cf_stats_snapshot_.ingest_files_addfile;
-  snprintf(buf, sizeof(buf), "AddFile(Total Files): cumulative %" PRIu64
-                             ", interval %" PRIu64 "\n",
+  snprintf(buf, sizeof(buf),
+           "AddFile(Total Files): cumulative %" PRIu64 ", interval %" PRIu64
+           "\n",
           ingest_files_addfile, interval_ingest_files_addfile);
  value->append(buf);

@@ -1262,7 +1327,9 @@ void InternalStats::DumpCFFileHistogram(std::string* value) {

 #else

-const DBPropertyInfo* GetPropertyInfo(const Slice& property) { return nullptr; }
+const DBPropertyInfo* GetPropertyInfo(const Slice& /*property*/) {
+  return nullptr;
+}

 #endif  // !ROCKSDB_LITE

@@ -19,8 +19,8 @@ class ColumnFamilyData;

 namespace rocksdb {

-class MemTableList;
 class DBImpl;
+class MemTableList;

 // Config for retrieving a property's value.
 struct DBPropertyInfo {
@@ -163,7 +163,10 @@ class InternalStats {
    // Number of compactions done
    int count;

-    explicit CompactionStats(int _count = 0)
+    // Number of compactions done per CompactionReason
+    int counts[static_cast<int>(CompactionReason::kNumOfReasons)];
+
+    explicit CompactionStats()
        : micros(0),
          bytes_read_non_output_levels(0),
          bytes_read_output_level(0),
@@ -174,7 +177,36 @@ class InternalStats {
          num_output_files(0),
          num_input_records(0),
          num_dropped_records(0),
-          count(_count) {}
+          count(0) {
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i < num_of_reasons; i++) {
+        counts[i] = 0;
+      }
+    }
+
+    explicit CompactionStats(CompactionReason reason, int c)
+        : micros(0),
+          bytes_read_non_output_levels(0),
+          bytes_read_output_level(0),
+          bytes_written(0),
+          bytes_moved(0),
+          num_input_files_in_non_output_levels(0),
+          num_input_files_in_output_level(0),
+          num_output_files(0),
+          num_input_records(0),
+          num_dropped_records(0),
+          count(c) {
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i < num_of_reasons; i++) {
+        counts[i] = 0;
+      }
+      int r = static_cast<int>(reason);
+      if (r >= 0 && r < num_of_reasons) {
+        counts[r] = c;
+      } else {
+        count = 0;
+      }
+    }

    explicit CompactionStats(const CompactionStats& c)
        : micros(c.micros),
@@ -189,7 +221,12 @@ class InternalStats {
          num_output_files(c.num_output_files),
          num_input_records(c.num_input_records),
          num_dropped_records(c.num_dropped_records),
-          count(c.count) {}
+          count(c.count) {
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i < num_of_reasons; i++) {
+        counts[i] = c.counts[i];
+      }
+    }

    void Clear() {
      this->micros = 0;
@@ -203,6 +240,10 @@ class InternalStats {
      this->num_input_records = 0;
      this->num_dropped_records = 0;
      this->count = 0;
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i < num_of_reasons; i++) {
+        counts[i] = 0;
+      }
    }

    void Add(const CompactionStats& c) {
@@ -219,6 +260,10 @@ class InternalStats {
      this->num_input_records += c.num_input_records;
      this->num_dropped_records += c.num_dropped_records;
      this->count += c.count;
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i< num_of_reasons; i++) {
+        counts[i] += c.counts[i];
+      }
    }

    void Subtract(const CompactionStats& c) {
@@ -235,6 +280,10 @@ class InternalStats {
      this->num_input_records -= c.num_input_records;
      this->num_dropped_records -= c.num_dropped_records;
      this->count -= c.count;
+      int num_of_reasons = static_cast<int>(CompactionReason::kNumOfReasons);
+      for (int i = 0; i < num_of_reasons; i++) {
+        counts[i] -= c.counts[i];
+      }
    }
  };

@@ -307,6 +356,10 @@ class InternalStats {
  bool GetIntPropertyOutOfMutex(const DBPropertyInfo& property_info,
                                Version* version, uint64_t* value);

+  const std::vector<CompactionStats>& TEST_GetCompactionStats() const {
+    return comp_stats_;
+  }
+
  // Store a mapping from the user-facing DB::Properties string to our
  // DBPropertyInfo struct used internally for retrieving properties.
  static const std::unordered_map<std::string, DBPropertyInfo> ppt_name_to_info;
@@ -322,6 +375,8 @@ class InternalStats {
  void DumpCFStatsNoFileHistogram(std::string* value);
  void DumpCFFileHistogram(std::string* value);

+  bool HandleBlockCacheStat(Cache** block_cache);
+
  // Per-DB stats
  std::atomic<uint64_t> db_stats_[INTERNAL_DB_STATS_ENUM_MAX];
  // Per-ColumnFamily stats
@@ -350,8 +405,7 @@ class InternalStats {
    uint64_t ingest_keys_addfile;      // Total number of keys ingested

    CFStatsSnapshot()
-        : comp_stats(0),
-          ingest_bytes_flush(0),
+        : ingest_bytes_flush(0),
          stall_count(0),
          compact_bytes_write(0),
          compact_bytes_read(0),
@@ -480,6 +534,10 @@ class InternalStats {
  bool HandleIsWriteStopped(uint64_t* value, DBImpl* db, Version* version);
  bool HandleEstimateOldestKeyTime(uint64_t* value, DBImpl* db,
                                   Version* version);
+  bool HandleBlockCacheCapacity(uint64_t* value, DBImpl* db, Version* version);
+  bool HandleBlockCacheUsage(uint64_t* value, DBImpl* db, Version* version);
+  bool HandleBlockCachePinnedUsage(uint64_t* value, DBImpl* db,
+                                   Version* version);

  // Total number of background errors encountered. Every time a flush task
  // or compaction task fails, this counter is incremented. The failure can
@@ -528,7 +586,7 @@ class InternalStats {
    INTERNAL_DB_STATS_ENUM_MAX,
  };

-  InternalStats(int num_levels, Env* env, ColumnFamilyData* cfd) {}
+  InternalStats(int /*num_levels*/, Env* /*env*/, ColumnFamilyData* /*cfd*/) {}

  struct CompactionStats {
    uint64_t micros;
@@ -543,48 +601,50 @@ class InternalStats {
    uint64_t num_dropped_records;
    int count;

-    explicit CompactionStats(int _count = 0) {}
+    explicit CompactionStats() {}

-    explicit CompactionStats(const CompactionStats& c) {}
+    explicit CompactionStats(CompactionReason /*reason*/, int /*c*/) {}

-    void Add(const CompactionStats& c) {}
+    explicit CompactionStats(const CompactionStats& /*c*/) {}

-    void Subtract(const CompactionStats& c) {}
+    void Add(const CompactionStats& /*c*/) {}
+
+    void Subtract(const CompactionStats& /*c*/) {}
  };

-  void AddCompactionStats(int level, const CompactionStats& stats) {}
+  void AddCompactionStats(int /*level*/, const CompactionStats& /*stats*/) {}

-  void IncBytesMoved(int level, uint64_t amount) {}
+  void IncBytesMoved(int /*level*/, uint64_t /*amount*/) {}

-  void AddCFStats(InternalCFStatsType type, uint64_t value) {}
+  void AddCFStats(InternalCFStatsType /*type*/, uint64_t /*value*/) {}

-  void AddDBStats(InternalDBStatsType type, uint64_t value,
-                  bool concurrent = false) {}
+  void AddDBStats(InternalDBStatsType /*type*/, uint64_t /*value*/,
+                  bool /*concurrent */ = false) {}

-  HistogramImpl* GetFileReadHist(int level) { return nullptr; }
+  HistogramImpl* GetFileReadHist(int /*level*/) { return nullptr; }

  uint64_t GetBackgroundErrorCount() const { return 0; }

  uint64_t BumpAndGetBackgroundErrorCount() { return 0; }

-  bool GetStringProperty(const DBPropertyInfo& property_info,
-                         const Slice& property, std::string* value) {
+  bool GetStringProperty(const DBPropertyInfo& /*property_info*/,
+                         const Slice& /*property*/, std::string* /*value*/) {
    return false;
  }

-  bool GetMapProperty(const DBPropertyInfo& property_info,
-                      const Slice& property,
-                      std::map<std::string, std::string>* value) {
+  bool GetMapProperty(const DBPropertyInfo& /*property_info*/,
+                      const Slice& /*property*/,
+                      std::map<std::string, std::string>* /*value*/) {
    return false;
  }

-  bool GetIntProperty(const DBPropertyInfo& property_info, uint64_t* value,
-                      DBImpl* db) const {
+  bool GetIntProperty(const DBPropertyInfo& /*property_info*/, uint64_t* /*value*/,
+                      DBImpl* /*db*/) const {
    return false;
  }

-  bool GetIntPropertyOutOfMutex(const DBPropertyInfo& property_info,
-                                Version* version, uint64_t* value) const {
+  bool GetIntPropertyOutOfMutex(const DBPropertyInfo& /*property_info*/,
+                                Version* /*version*/, uint64_t* /*value*/) const {
    return false;
  }
 };
@@ -27,7 +27,9 @@ struct SuperVersionContext {
  };

  autovector<SuperVersion*> superversions_to_free;
+#ifndef ROCKSDB_DISABLE_STALL_NOTIFICATION
  autovector<WriteStallNotification> write_stall_notifications;
+#endif
  unique_ptr<SuperVersion> new_superversion;  // if nullptr no new superversion

  explicit SuperVersionContext(bool create_superversion = false)
@@ -38,28 +40,37 @@ struct SuperVersionContext {
  }

  inline bool HaveSomethingToDelete() const {
-    return superversions_to_free.size() > 0 ||
-           write_stall_notifications.size() > 0;
+#ifndef ROCKSDB_DISABLE_STALL_NOTIFICATION
+    return !superversions_to_free.empty() ||
+           !write_stall_notifications.empty();
+#else
+    return !superversions_to_free.empty();
+#endif
  }

  void PushWriteStallNotification(
      WriteStallCondition old_cond, WriteStallCondition new_cond,
      const std::string& name, const ImmutableCFOptions* ioptions) {
-#ifndef ROCKSDB_LITE
+#if !defined(ROCKSDB_LITE) && !defined(ROCKSDB_DISABLE_STALL_NOTIFICATION)
    WriteStallNotification notif;
    notif.write_stall_info.cf_name = name;
    notif.write_stall_info.condition.prev = old_cond;
    notif.write_stall_info.condition.cur = new_cond;
    notif.immutable_cf_options = ioptions;
    write_stall_notifications.push_back(notif);
-#endif  // !ROCKSDB_LITE
+#else
+    (void)old_cond;
+    (void)new_cond;
+    (void)name;
+    (void)ioptions;
+#endif  // !defined(ROCKSDB_LITE) && !defined(ROCKSDB_DISABLE_STALL_NOTIFICATION)
  }

  void Clean() {
-#ifndef ROCKSDB_LITE
+#if !defined(ROCKSDB_LITE) && !defined(ROCKSDB_DISABLE_STALL_NOTIFICATION)
    // notify listeners on changed write stall conditions
    for (auto& notif : write_stall_notifications) {
-      for (auto listener : notif.immutable_cf_options->listeners) {
+      for (auto& listener : notif.immutable_cf_options->listeners) {
        listener->OnStallConditionsChanged(notif.write_stall_info);
      }
    }
@@ -73,8 +84,10 @@ struct SuperVersionContext {
  }

  ~SuperVersionContext() {
-    assert(write_stall_notifications.size() == 0);
-    assert(superversions_to_free.size() == 0);
+#ifndef ROCKSDB_DISABLE_STALL_NOTIFICATION
+    assert(write_stall_notifications.empty());
+#endif
+    assert(superversions_to_free.empty());
  }
 };

@@ -92,11 +105,12 @@ struct JobContext {
  // Structure to store information for candidate files to delete.
  struct CandidateFileInfo {
    std::string file_name;
-    uint32_t path_id;
-    CandidateFileInfo(std::string name, uint32_t path)
-        : file_name(std::move(name)), path_id(path) {}
+    std::string file_path;
+    CandidateFileInfo(std::string name, std::string path)
+        : file_name(std::move(name)), file_path(std::move(path)) {}
    bool operator==(const CandidateFileInfo& other) const {
-      return file_name == other.file_name && path_id == other.path_id;
+      return file_name == other.file_name &&
+             file_path == other.file_path;
    }
  };

@@ -113,7 +127,7 @@ struct JobContext {
  std::vector<FileDescriptor> sst_live;

  // a list of sst files that we need to delete
-  std::vector<FileMetaData*> sst_delete_files;
+  std::vector<ObsoleteFileInfo> sst_delete_files;

  // a list of log files that we need to delete
  std::vector<uint64_t> log_delete_files;
@@ -260,7 +260,7 @@ TEST_F(EventListenerTest, OnSingleDBFlushTest) {
    ASSERT_EQ(listener->flushed_column_family_names_.size(), i);
  }

-  // make sure call-back functions are called in the right order
+  // make sure callback functions are called in the right order
  for (size_t i = 0; i < cf_names.size(); ++i) {
    ASSERT_EQ(listener->flushed_dbs_[i], db_);
    ASSERT_EQ(listener->flushed_column_family_names_[i], cf_names[i]);
@@ -296,7 +296,7 @@ TEST_F(EventListenerTest, MultiCF) {
    ASSERT_EQ(listener->flushed_column_family_names_.size(), i);
  }

-  // make sure call-back functions are called in the right order
+  // make sure callback functions are called in the right order
  for (size_t i = 0; i < cf_names.size(); i++) {
    ASSERT_EQ(listener->flushed_dbs_[i], db_);
    ASSERT_EQ(listener->flushed_column_family_names_[i], cf_names[i]);
@@ -57,9 +57,11 @@ Status Writer::AddRecord(const Slice& slice) {
        // Fill the trailer (literal below relies on kHeaderSize and
        // kRecyclableHeaderSize being <= 11)
        assert(header_size <= 11);
-        dest_->Append(
-            Slice("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
-                  static_cast<size_t>(leftover)));
+        s = dest_->Append(Slice("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+                                static_cast<size_t>(leftover)));
+        if (!s.ok()) {
+          break;
+        }
      }
      block_offset_ = 0;
    }
@@ -90,6 +92,8 @@ Status Writer::AddRecord(const Slice& slice) {
  return s;
 }

+bool Writer::TEST_BufferIsEmpty() { return dest_->TEST_BufferIsEmpty(); }
+
 Status Writer::EmitPhysicalRecord(RecordType t, const char* ptr, size_t n) {
  assert(n <= 0xffff);  // Must fit in two bytes

@@ -85,6 +85,8 @@ class Writer {

  Status WriteBuffer();

+  bool TEST_BufferIsEmpty();
+
 private:
  unique_ptr<WritableFileWriter> dest_;
  size_t block_offset_;       // Current offset in block
@@ -0,0 +1,67 @@
+//  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/logs_with_prep_tracker.h"
+
+#include "port/likely.h"
+
+namespace rocksdb {
+void LogsWithPrepTracker::MarkLogAsHavingPrepSectionFlushed(uint64_t log) {
+  assert(log != 0);
+  std::lock_guard<std::mutex> lock(prepared_section_completed_mutex_);
+  auto it = prepared_section_completed_.find(log);
+  if (UNLIKELY(it == prepared_section_completed_.end())) {
+    prepared_section_completed_[log] = 1;
+  } else {
+    it->second += 1;
+  }
+}
+
+void LogsWithPrepTracker::MarkLogAsContainingPrepSection(uint64_t log) {
+  assert(log != 0);
+  std::lock_guard<std::mutex> lock(logs_with_prep_mutex_);
+
+  auto rit = logs_with_prep_.rbegin();
+  bool updated = false;
+  // Most probably the last log is the one that is being marked for
+  // having a prepare section; so search from the end.
+  for (; rit != logs_with_prep_.rend() && rit->log >= log; ++rit) {
+    if (rit->log == log) {
+      rit->cnt++;
+      updated = true;
+      break;
+    }
+  }
+  if (!updated) {
+    // We are either at the start, or at a position with rit->log < log
+    logs_with_prep_.insert(rit.base(), {log, 1});
+  }
+}
+
+uint64_t LogsWithPrepTracker::FindMinLogContainingOutstandingPrep() {
+  std::lock_guard<std::mutex> lock(logs_with_prep_mutex_);
+  auto it = logs_with_prep_.begin();
+  // start with the smallest log
+  for (; it != logs_with_prep_.end();) {
+    auto min_log = it->log;
+    {
+      std::lock_guard<std::mutex> lock2(prepared_section_completed_mutex_);
+      auto completed_it = prepared_section_completed_.find(min_log);
+      if (completed_it == prepared_section_completed_.end() ||
+          completed_it->second < it->cnt) {
+        return min_log;
+      }
+      assert(completed_it != prepared_section_completed_.end() &&
+             completed_it->second == it->cnt);
+      prepared_section_completed_.erase(completed_it);
+    }
+    // erase from beginning in vector is not efficient but this function is not
+    // on the fast path.
+    it = logs_with_prep_.erase(it);
+  }
+  // no such log found
+  return 0;
+}
+}  // namespace rocksdb
@@ -0,0 +1,61 @@
+//  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 <stdint.h>
+#include <cassert>
+#include <cstdlib>
+#include <mutex>
+#include <unordered_map>
+#include <vector>
+
+namespace rocksdb {
+
+// This class is used to track the log files with outstanding prepare entries.
+class LogsWithPrepTracker {
+ public:
+  // Called when a transaction prepared in `log` has been committed or aborted.
+  void MarkLogAsHavingPrepSectionFlushed(uint64_t log);
+  // Called when a transaction is prepared in `log`.
+  void MarkLogAsContainingPrepSection(uint64_t log);
+  // Return the earliest log file with outstanding prepare entries.
+  uint64_t FindMinLogContainingOutstandingPrep();
+  size_t TEST_PreparedSectionCompletedSize() {
+    return prepared_section_completed_.size();
+  }
+  size_t TEST_LogsWithPrepSize() { return logs_with_prep_.size(); }
+
+ private:
+  // REQUIRES: logs_with_prep_mutex_ held
+  //
+  // sorted list of log numbers still containing prepared data.
+  // this is used by FindObsoleteFiles to determine which
+  // flushed logs we must keep around because they still
+  // contain prepared data which has not been committed or rolled back
+  struct LogCnt {
+    uint64_t log;  // the log number
+    uint64_t cnt;  // number of prepared sections in the log
+  };
+  std::vector<LogCnt> logs_with_prep_;
+  std::mutex logs_with_prep_mutex_;
+
+  // REQUIRES: prepared_section_completed_mutex_ held
+  //
+  // to be used in conjunction with logs_with_prep_.
+  // once a transaction with data in log L is committed or rolled back
+  // rather than updating logs_with_prep_ directly we keep track of that
+  // in prepared_section_completed_ which maps LOG -> instance_count. This helps
+  // avoiding contention between a commit thread and the prepare threads.
+  //
+  // when trying to determine the minimum log still active we first
+  // consult logs_with_prep_. while that root value maps to
+  // an equal value in prepared_section_completed_ we erase the log from
+  // both logs_with_prep_ and prepared_section_completed_.
+  std::unordered_map<uint64_t, uint64_t> prepared_section_completed_;
+  std::mutex prepared_section_completed_mutex_;
+
+};
+}  // namespace rocksdb
@@ -101,9 +101,7 @@ void ManagedIterator::SeekToLast() {
  }
  assert(mutable_iter_ != nullptr);
  mutable_iter_->SeekToLast();
-  if (mutable_iter_->status().ok()) {
-    UpdateCurrent();
-  }
+  UpdateCurrent();
 }

 void ManagedIterator::SeekToFirst() {
@@ -146,27 +144,13 @@ void ManagedIterator::Prev() {
  }
  MILock l(&in_use_, this);
  if (NeedToRebuild()) {
-    std::string current_key = key().ToString();
-    Slice old_key(current_key);
-    RebuildIterator();
-    SeekInternal(old_key, false);
-    UpdateCurrent();
+    RebuildIterator(true);
    if (!valid_) {
      return;
    }
-    if (key().compare(old_key) != 0) {
-      valid_ = false;
-      status_ = Status::Incomplete("Cannot do Prev now");
-      return;
-    }
  }
  mutable_iter_->Prev();
-  if (mutable_iter_->status().ok()) {
-    UpdateCurrent();
-    status_ = Status::OK();
-  } else {
-    status_ = mutable_iter_->status();
-  }
+  UpdateCurrent();
 }

 void ManagedIterator::Next() {
@@ -176,19 +160,10 @@ void ManagedIterator::Next() {
  }
  MILock l(&in_use_, this);
  if (NeedToRebuild()) {
-    std::string current_key = key().ToString();
-    Slice old_key(current_key.data(), cached_key_.Size());
-    RebuildIterator();
-    SeekInternal(old_key, false);
-    UpdateCurrent();
+    RebuildIterator(true);
    if (!valid_) {
      return;
    }
-    if (key().compare(old_key) != 0) {
-      valid_ = false;
-      status_ = Status::Incomplete("Cannot do Next now");
-      return;
-    }
  }
  mutable_iter_->Next();
  UpdateCurrent();
@@ -206,21 +181,38 @@ Slice ManagedIterator::value() const {

 Status ManagedIterator::status() const { return status_; }

-void ManagedIterator::RebuildIterator() {
+void ManagedIterator::RebuildIterator(bool reseek) {
+  std::string current_key;
+  if (reseek) {
+    current_key = key().ToString();
+  }
+
  svnum_ = cfd_->GetSuperVersionNumber();
  mutable_iter_ = unique_ptr<Iterator>(db_->NewIterator(read_options_, &cfh_));
+
+  if (reseek) {
+    Slice old_key(current_key.data(), current_key.size());
+    SeekInternal(old_key, false);
+    UpdateCurrent();
+    if (!valid_ || key().compare(old_key) != 0) {
+      valid_ = false;
+      status_ = Status::Incomplete(
+          "Next/Prev failed because current key has "
+          "been removed");
+    }
+  }
 }

 void ManagedIterator::UpdateCurrent() {
  assert(mutable_iter_ != nullptr);

  valid_ = mutable_iter_->Valid();
+  status_ = mutable_iter_->status();
+
  if (!valid_) {
-    status_ = mutable_iter_->status();
    return;
  }

-  status_ = Status::OK();
  cached_key_.SetUserKey(mutable_iter_->key());
  cached_value_.SetUserKey(mutable_iter_->value());
 }
@@ -54,7 +54,7 @@ class ManagedIterator : public Iterator {
  }

 private:
-  void RebuildIterator();
+  void RebuildIterator(bool reseek = false);
  void UpdateCurrent();
  void SeekInternal(const Slice& user_key, bool seek_to_first);
  bool NeedToRebuild();
@@ -19,7 +19,12 @@ using namespace rocksdb;

 namespace {

-const int kNumKeys = 1100000;
+// Reasoning: previously the number was 1100000. Since the keys are written to
+// the batch in one write each write will result into one SST file. each write
+// will result into one SST file. We reduced the write_buffer_size to 1K to
+// basically have the same effect with however less number of keys, which
+// results into less test runtime.
+const int kNumKeys = 1100;

 std::string Key1(int i) {
  char buf[100];
@@ -99,6 +104,7 @@ TEST_F(ManualCompactionTest, Test) {
  // specific scenario.
  rocksdb::DB* db;
  rocksdb::Options db_options;
+  db_options.write_buffer_size = 1024;
  db_options.create_if_missing = true;
  db_options.compression = rocksdb::kNoCompression;
  ASSERT_OK(rocksdb::DB::Open(db_options, dbname_, &db));
@@ -74,8 +74,8 @@ MemTable::MemTable(const InternalKeyComparator& cmp,
              : nullptr,
          mutable_cf_options.memtable_huge_page_size),
      table_(ioptions.memtable_factory->CreateMemTableRep(
-          comparator_, &arena_, ioptions.prefix_extractor, ioptions.info_log,
-          column_family_id)),
+          comparator_, &arena_, mutable_cf_options.prefix_extractor.get(),
+          ioptions.info_log, column_family_id)),
      range_del_table_(SkipListFactory().CreateMemTableRep(
          comparator_, &arena_, nullptr /* transform */, ioptions.info_log,
          column_family_id)),
@@ -95,7 +95,7 @@ MemTable::MemTable(const InternalKeyComparator& cmp,
      locks_(moptions_.inplace_update_support
                 ? moptions_.inplace_update_num_locks
                 : 0),
-      prefix_extractor_(ioptions.prefix_extractor),
+      prefix_extractor_(mutable_cf_options.prefix_extractor.get()),
      flush_state_(FLUSH_NOT_REQUESTED),
      env_(ioptions.env),
      insert_with_hint_prefix_extractor_(
@@ -229,7 +229,7 @@ int MemTable::KeyComparator::operator()(const char* prefix_len_key1,
 }

 int MemTable::KeyComparator::operator()(const char* prefix_len_key,
-                                        const Slice& key)
+                                        const KeyComparator::DecodedType& key)
    const {
  // Internal keys are encoded as length-prefixed strings.
  Slice a = GetLengthPrefixedSlice(prefix_len_key);
@@ -479,12 +479,12 @@ bool MemTable::Add(SequenceNumber s, ValueType type,
        insert_with_hint_prefix_extractor_->InDomain(key_slice)) {
      Slice prefix = insert_with_hint_prefix_extractor_->Transform(key_slice);
      bool res = table->InsertKeyWithHint(handle, &insert_hints_[prefix]);
-      if (!res) {
+      if (UNLIKELY(!res)) {
        return res;
      }
    } else {
      bool res = table->InsertKey(handle);
-      if (!res) {
+      if (UNLIKELY(!res)) {
        return res;
      }
    }
@@ -520,7 +520,7 @@ bool MemTable::Add(SequenceNumber s, ValueType type,
    UpdateFlushState();
  } else {
    bool res = table->InsertKeyConcurrently(handle);
-    if (!res) {
+    if (UNLIKELY(!res)) {
      return res;
    }

@@ -64,7 +64,7 @@ struct MemTablePostProcessInfo {
 };

 // Note:  Many of the methods in this class have comments indicating that
-// external synchromization is required as these methods are not thread-safe.
+// external synchronization is required as these methods are not thread-safe.
 // It is up to higher layers of code to decide how to prevent concurrent
 // invokation of these methods.  This is usually done by acquiring either
 // the db mutex or the single writer thread.
@@ -84,7 +84,7 @@ class MemTable {
    virtual int operator()(const char* prefix_len_key1,
                           const char* prefix_len_key2) const override;
    virtual int operator()(const char* prefix_len_key,
-                           const Slice& key) const override;
+                           const DecodedType& key) const override;
  };

  // MemTables are reference counted.  The initial reference count
@@ -12,6 +12,7 @@
 #include <inttypes.h>
 #include <limits>
 #include <string>
+#include "db/db_impl.h"
 #include "db/memtable.h"
 #include "db/version_set.h"
 #include "monitoring/thread_status_util.h"
@@ -322,9 +323,10 @@ void MemTableList::RollbackMemtableFlush(const autovector<MemTable*>& mems,
 // Record a successful flush in the manifest file
 Status MemTableList::InstallMemtableFlushResults(
    ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options,
-    const autovector<MemTable*>& mems, VersionSet* vset, InstrumentedMutex* mu,
-    uint64_t file_number, autovector<MemTable*>* to_delete,
-    Directory* db_directory, LogBuffer* log_buffer) {
+    const autovector<MemTable*>& mems, LogsWithPrepTracker* prep_tracker,
+    VersionSet* vset, InstrumentedMutex* mu, uint64_t file_number,
+    autovector<MemTable*>* to_delete, Directory* db_directory,
+    LogBuffer* log_buffer) {
  AutoThreadOperationStageUpdater stage_updater(
      ThreadStatus::STAGE_MEMTABLE_INSTALL_FLUSH_RESULTS);
  mu->AssertHeld();
@@ -361,6 +363,7 @@ Status MemTableList::InstallMemtableFlushResults(
    uint64_t batch_file_number = 0;
    size_t batch_count = 0;
    autovector<VersionEdit*> edit_list;
+    autovector<MemTable*> memtables_to_flush;
    // enumerate from the last (earliest) element to see how many batch finished
    for (auto it = memlist.rbegin(); it != memlist.rend(); ++it) {
      MemTable* m = *it;
@@ -373,11 +376,20 @@ Status MemTableList::InstallMemtableFlushResults(
                         "[%s] Level-0 commit table #%" PRIu64 " started",
                         cfd->GetName().c_str(), m->file_number_);
        edit_list.push_back(&m->edit_);
+        memtables_to_flush.push_back(m);
      }
      batch_count++;
    }

    if (batch_count > 0) {
+      if (vset->db_options()->allow_2pc) {
+        assert(edit_list.size() > 0);
+        // We piggyback the information of  earliest log file to keep in the
+        // manifest entry for the last file flushed.
+        edit_list.back()->SetMinLogNumberToKeep(PrecomputeMinLogNumberToKeep(
+            vset, *cfd, edit_list, memtables_to_flush, prep_tracker));
+      }
+
      // this can release and reacquire the mutex.
      s = vset->LogAndApply(cfd, mutable_cf_options, edit_list, mu,
                            db_directory);
@@ -468,13 +480,21 @@ void MemTableList::InstallNewVersion() {
  }
 }

-uint64_t MemTableList::GetMinLogContainingPrepSection() {
+uint64_t MemTableList::PrecomputeMinLogContainingPrepSection(
+    const autovector<MemTable*>& memtables_to_flush) {
  uint64_t min_log = 0;

  for (auto& m : current_->memlist_) {
-    // this mem has been flushed it no longer
-    // needs to hold on the its prep section
-    if (m->flush_completed_) {
+    // Assume the list is very short, we can live with O(m*n). We can optimize
+    // if the performance has some problem.
+    bool should_skip = false;
+    for (MemTable* m_to_flush : memtables_to_flush) {
+      if (m == m_to_flush) {
+        should_skip = true;
+        break;
+      }
+    }
+    if (should_skip) {
      continue;
    }

@@ -13,6 +13,7 @@
 #include <vector>

 #include "db/dbformat.h"
+#include "db/logs_with_prep_tracker.h"
 #include "db/memtable.h"
 #include "db/range_del_aggregator.h"
 #include "monitoring/instrumented_mutex.h"
@@ -210,9 +211,10 @@ class MemTableList {
  // Commit a successful flush in the manifest file
  Status InstallMemtableFlushResults(
      ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options,
-      const autovector<MemTable*>& m, VersionSet* vset, InstrumentedMutex* mu,
-      uint64_t file_number, autovector<MemTable*>* to_delete,
-      Directory* db_directory, LogBuffer* log_buffer);
+      const autovector<MemTable*>& m, LogsWithPrepTracker* prep_tracker,
+      VersionSet* vset, InstrumentedMutex* mu, uint64_t file_number,
+      autovector<MemTable*>* to_delete, Directory* db_directory,
+      LogBuffer* log_buffer);

  // New memtables are inserted at the front of the list.
  // Takes ownership of the referenced held on *m by the caller of Add().
@@ -243,7 +245,10 @@ class MemTableList {

  size_t* current_memory_usage() { return &current_memory_usage_; }

-  uint64_t GetMinLogContainingPrepSection();
+  // Returns the min log containing the prep section after memtables listsed in
+  // `memtables_to_flush` are flushed and their status is persisted in manifest.
+  uint64_t PrecomputeMinLogContainingPrepSection(
+      const autovector<MemTable*>& memtables_to_flush);

  uint64_t GetEarliestMemTableID() const {
    auto& memlist = current_->memlist_;
@@ -82,10 +82,10 @@ class MemTableListTest : public testing::Test {
    // Create dummy mutex.
    InstrumentedMutex mutex;
    InstrumentedMutexLock l(&mutex);
-
-    return list->InstallMemtableFlushResults(cfd, mutable_cf_options, m,
-                                             &versions, &mutex, 1, to_delete,
-                                             nullptr, &log_buffer);
+    LogsWithPrepTracker dummy_prep_tracker;
+    return list->InstallMemtableFlushResults(
+        cfd, mutable_cf_options, m, &dummy_prep_tracker, &versions, &mutex, 1,
+        to_delete, nullptr, &log_buffer);
  }
 };

@@ -0,0 +1,217 @@
+//  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.
+
+#ifndef ROCKSDB_LITE
+
+#include <stdlib.h>
+#include <map>
+#include <string>
+#include <vector>
+#include "db/db_impl.h"
+#include "db/version_set.h"
+#include "db/write_batch_internal.h"
+#include "rocksdb/db.h"
+#include "rocksdb/env.h"
+#include "rocksdb/transaction_log.h"
+#include "util/filename.h"
+#include "util/string_util.h"
+#include "util/sync_point.h"
+#include "util/testharness.h"
+#include "util/testutil.h"
+
+using std::cerr;
+using std::cout;
+using std::endl;
+using std::flush;
+
+namespace rocksdb {
+
+class ObsoleteFilesTest : public testing::Test {
+ public:
+  std::string dbname_;
+  Options options_;
+  DB* db_;
+  Env* env_;
+  int numlevels_;
+
+  ObsoleteFilesTest() {
+    db_ = nullptr;
+    env_ = Env::Default();
+    // Trigger compaction when the number of level 0 files reaches 2.
+    options_.level0_file_num_compaction_trigger = 2;
+    options_.disable_auto_compactions = false;
+    options_.delete_obsolete_files_period_micros = 0;  // always do full purge
+    options_.enable_thread_tracking = true;
+    options_.write_buffer_size = 1024*1024*1000;
+    options_.target_file_size_base = 1024*1024*1000;
+    options_.max_bytes_for_level_base = 1024*1024*1000;
+    options_.WAL_ttl_seconds = 300; // Used to test log files
+    options_.WAL_size_limit_MB = 1024; // Used to test log files
+    dbname_ = test::TmpDir() + "/obsolete_files_test";
+    options_.wal_dir = dbname_ + "/wal_files";
+
+    // clean up all the files that might have been there before
+    std::vector<std::string> old_files;
+    env_->GetChildren(dbname_, &old_files);
+    for (auto file : old_files) {
+      env_->DeleteFile(dbname_ + "/" + file);
+    }
+    env_->GetChildren(options_.wal_dir, &old_files);
+    for (auto file : old_files) {
+      env_->DeleteFile(options_.wal_dir + "/" + file);
+    }
+
+    DestroyDB(dbname_, options_);
+    numlevels_ = 7;
+    EXPECT_OK(ReopenDB(true));
+  }
+
+  Status ReopenDB(bool create) {
+    delete db_;
+    if (create) {
+      DestroyDB(dbname_, options_);
+    }
+    db_ = nullptr;
+    options_.create_if_missing = create;
+    return DB::Open(options_, dbname_, &db_);
+  }
+
+  void CloseDB() {
+    delete db_;
+    db_ = nullptr;
+  }
+
+  void AddKeys(int numkeys, int startkey) {
+    WriteOptions options;
+    options.sync = false;
+    for (int i = startkey; i < (numkeys + startkey) ; i++) {
+      std::string temp = ToString(i);
+      Slice key(temp);
+      Slice value(temp);
+      ASSERT_OK(db_->Put(options, key, value));
+    }
+  }
+
+  int numKeysInLevels(
+    std::vector<LiveFileMetaData> &metadata,
+    std::vector<int> *keysperlevel = nullptr) {
+
+    if (keysperlevel != nullptr) {
+      keysperlevel->resize(numlevels_);
+    }
+
+    int numKeys = 0;
+    for (size_t i = 0; i < metadata.size(); i++) {
+      int startkey = atoi(metadata[i].smallestkey.c_str());
+      int endkey = atoi(metadata[i].largestkey.c_str());
+      int numkeysinfile = (endkey - startkey + 1);
+      numKeys += numkeysinfile;
+      if (keysperlevel != nullptr) {
+        (*keysperlevel)[(int)metadata[i].level] += numkeysinfile;
+      }
+      fprintf(stderr, "level %d name %s smallest %s largest %s\n",
+              metadata[i].level, metadata[i].name.c_str(),
+              metadata[i].smallestkey.c_str(),
+              metadata[i].largestkey.c_str());
+    }
+    return numKeys;
+  }
+
+  void createLevel0Files(int numFiles, int numKeysPerFile) {
+    int startKey = 0;
+    DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
+    for (int i = 0; i < numFiles; i++) {
+      AddKeys(numKeysPerFile, startKey);
+      startKey += numKeysPerFile;
+      ASSERT_OK(dbi->TEST_FlushMemTable());
+      ASSERT_OK(dbi->TEST_WaitForFlushMemTable());
+    }
+  }
+
+  void CheckFileTypeCounts(std::string& dir,
+                            int required_log,
+                            int required_sst,
+                            int required_manifest) {
+    std::vector<std::string> filenames;
+    env_->GetChildren(dir, &filenames);
+
+    int log_cnt = 0, sst_cnt = 0, manifest_cnt = 0;
+    for (auto file : filenames) {
+      uint64_t number;
+      FileType type;
+      if (ParseFileName(file, &number, &type)) {
+        log_cnt += (type == kLogFile);
+        sst_cnt += (type == kTableFile);
+        manifest_cnt += (type == kDescriptorFile);
+      }
+    }
+    ASSERT_EQ(required_log, log_cnt);
+    ASSERT_EQ(required_sst, sst_cnt);
+    ASSERT_EQ(required_manifest, manifest_cnt);
+  }
+};
+
+TEST_F(ObsoleteFilesTest, RaceForObsoleteFileDeletion) {
+  createLevel0Files(2, 50000);
+  CheckFileTypeCounts(options_.wal_dir, 1, 0, 0);
+
+  SyncPoint::GetInstance()->LoadDependency({
+      {"DBImpl::BackgroundCallCompaction:FoundObsoleteFiles",
+       "ObsoleteFilesTest::RaceForObsoleteFileDeletion:1"},
+      {"DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles",
+       "ObsoleteFilesTest::RaceForObsoleteFileDeletion:2"},
+      });
+  SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::DeleteObsoleteFileImpl:AfterDeletion", [&](void* arg) {
+        Status* p_status = reinterpret_cast<Status*>(arg);
+        ASSERT_TRUE(p_status->ok());
+      });
+  SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::CloseHelper:PendingPurgeFinished", [&](void* arg) {
+        std::vector<uint64_t>* files_grabbed_for_purge_ptr =
+            reinterpret_cast<std::vector<uint64_t>*>(arg);
+        ASSERT_TRUE(files_grabbed_for_purge_ptr->empty());
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  DBImpl* dbi = reinterpret_cast<DBImpl*>(db_);
+  port::Thread user_thread([&]() {
+    JobContext jobCxt(0);
+    TEST_SYNC_POINT("ObsoleteFilesTest::RaceForObsoleteFileDeletion:1");
+    dbi->TEST_LockMutex();
+    dbi->FindObsoleteFiles(&jobCxt,
+      true /* force=true */, false /* no_full_scan=false */);
+    dbi->TEST_UnlockMutex();
+    TEST_SYNC_POINT("ObsoleteFilesTest::RaceForObsoleteFileDeletion:2");
+    dbi->PurgeObsoleteFiles(jobCxt);
+    jobCxt.Clean();
+  });
+
+  user_thread.join();
+
+  CloseDB();
+}
+
+} //namespace rocksdb
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+#else
+#include <stdio.h>
+
+int main(int /*argc*/, char** /*argv*/) {
+  fprintf(stderr,
+          "SKIPPED as DBImpl::DeleteFile is not supported in ROCKSDB_LITE\n");
+  return 0;
+}
+
+#endif  // !ROCKSDB_LITE
@@ -227,6 +227,9 @@ void ProfileQueries(bool enabled_time = false) {
  HistogramImpl hist_write_pre_post;
  HistogramImpl hist_write_wal_time;
  HistogramImpl hist_write_memtable_time;
+  HistogramImpl hist_write_delay_time;
+  HistogramImpl hist_write_thread_wait_nanos;
+  HistogramImpl hist_write_scheduling_time;

  uint64_t total_db_mutex_nanos = 0;

@@ -270,9 +273,15 @@ void ProfileQueries(bool enabled_time = false) {
      ThreadStatusUtil::TEST_SetStateDelay(ThreadStatus::STATE_MUTEX_WAIT, 0U);
 #endif
    }
-    hist_write_pre_post.Add(get_perf_context()->write_pre_and_post_process_time);
+    hist_write_pre_post.Add(
+        get_perf_context()->write_pre_and_post_process_time);
    hist_write_wal_time.Add(get_perf_context()->write_wal_time);
    hist_write_memtable_time.Add(get_perf_context()->write_memtable_time);
+    hist_write_delay_time.Add(get_perf_context()->write_delay_time);
+    hist_write_thread_wait_nanos.Add(
+        get_perf_context()->write_thread_wait_nanos);
+    hist_write_scheduling_time.Add(
+        get_perf_context()->write_scheduling_flushes_compactions_time);
    hist_put.Add(get_perf_context()->user_key_comparison_count);
    total_db_mutex_nanos += get_perf_context()->db_mutex_lock_nanos;
  }
@@ -320,6 +329,11 @@ void ProfileQueries(bool enabled_time = false) {
              << hist_write_wal_time.ToString() << "\n"
              << " Writing Mem Table time: \n"
              << hist_write_memtable_time.ToString() << "\n"
+              << " Write Delay: \n" << hist_write_delay_time.ToString() << "\n"
+              << " Waiting for Batch time: \n"
+              << hist_write_thread_wait_nanos.ToString() << "\n"
+              << " Scheduling Flushes and Compactions Time: \n"
+              << hist_write_scheduling_time.ToString() << "\n"
              << " Total DB mutex nanos: \n" << total_db_mutex_nanos << "\n";

    std::cout << "Get(): Time to get snapshot: \n"
@@ -359,6 +373,14 @@ void ProfileQueries(bool enabled_time = false) {
    ASSERT_GT(hist_mget_files.Average(), 0);
    ASSERT_GT(hist_mget_post_process.Average(), 0);
    ASSERT_GT(hist_mget_num_memtable_checked.Average(), 0);
+
+    EXPECT_GT(hist_write_pre_post.Average(), 0);
+    EXPECT_GT(hist_write_wal_time.Average(), 0);
+    EXPECT_GT(hist_write_memtable_time.Average(), 0);
+    EXPECT_EQ(hist_write_delay_time.Average(), 0);
+    EXPECT_EQ(hist_write_thread_wait_nanos.Average(), 0);
+    EXPECT_GT(hist_write_scheduling_time.Average(), 0);
+
 #ifndef NDEBUG
    ASSERT_GT(total_db_mutex_nanos, 2000U);
 #endif
@@ -262,11 +262,13 @@ class TestPlainTableReader : public PlainTableReader {
                       const TableProperties* table_properties,
                       unique_ptr<RandomAccessFileReader>&& file,
                       const ImmutableCFOptions& ioptions,
+                       const SliceTransform* prefix_extractor,
                       bool* expect_bloom_not_match, bool store_index_in_file,
                       uint32_t column_family_id,
                       const std::string& column_family_name)
      : PlainTableReader(ioptions, std::move(file), env_options, icomparator,
-                         encoding_type, file_size, table_properties),
+                         encoding_type, file_size, table_properties,
+                         prefix_extractor),
        expect_bloom_not_match_(expect_bloom_not_match) {
    Status s = MmapDataIfNeeded();
    EXPECT_TRUE(s.ok());
@@ -360,7 +362,8 @@ class TestPlainTableFactory : public PlainTableFactory {
        table_reader_options.env_options,
        table_reader_options.internal_comparator, encoding_type, file_size,
        bloom_bits_per_key_, hash_table_ratio_, index_sparseness_, props,
-        std::move(file), table_reader_options.ioptions, expect_bloom_not_match_,
+        std::move(file), table_reader_options.ioptions,
+        table_reader_options.prefix_extractor, expect_bloom_not_match_,
        store_index_in_file_, column_family_id_, column_family_name_));

    *table = std::move(new_reader);
--- a/Show More
+++ b/Show More