Andrew Ryan Chang
7c98a2d130
Summary: There is a `strict_capacity_limit` option which imposes a hard memory limit on the block cache. When the block cache is enabled, every read request is serviced from the block cache. If the required block is missing, it is first inserted into the cache. If `strict_capacity_limit` is `true` and the limit has been reached, the `Get` and `MultiGet` requests should fail. However, currently this is not happening for `MultiGet`. I updated `MultiGet` to explicitly check the returned status of `MaybeReadBlockAndLoadToCache`, so the status does not get overwritten later. Thank you anand1976 for the problem explanation. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13104 Test Plan: Added unit test for both `Get` and `MultiGet` with a `strict_capacity_limit` set. Before the change, half of my unit test cases failed https://github.com/facebook/rocksdb/actions/runs/11604597524/job/32313608085?pr=13104. After I added the check for the status returned by `MaybeReadBlockAndLoadToCache`, they all pass. I also ran these tests manually (I had to run `make clean` before): ``` make -j64 block_based_table_reader_test COMPILE_WITH_ASAN=1 ASSERT_STATUS_CHECKED=1 ./block_based_table_reader_test --gtest_filter="*StrictCapacityLimitReaderTest.Get*" ./block_based_table_reader_test --gtest_filter="*StrictCapacityLimitReaderTest.MultiGet*" ``` Reviewed By: anand1976 Differential Revision: D65302470 Pulled By: archang19 fbshipit-source-id: 28dcc381e67e05a89fa9fc9607b4709976d6d90e
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key-value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it especially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/main/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.
License
RocksDB is dual-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). You may select, at your option, one of the above-listed licenses.