defd97bc9d
Summary: add a new CF option `paranoid_memory_checks` that allows additional data integrity validations during read/scan. Currently, skiplist-based memtable will validate the order of keys visited. Further data validation can be added in different layers. The option will be opt-in due to performance overhead. The motivation for this feature is for services where data correctness is critical and want to detect in-memory corruption earlier. For a corrupted memtable key, this feature can help to detect it during during reads instead of during flush with existing protections (OutputValidator that verifies key order or per kv checksum). See internally linked task for more context. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12889 Test Plan: * new unit test added for paranoid_memory_checks=true. * existing unit test for paranoid_memory_checks=false. * enable in stress test. Performance Benchmark: we check for performance regression in read path where data is in memtable only. For each benchmark, the script was run at the same time for main and this PR: * Memtable-only randomread ops/sec: ``` (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --num=250000 --reads=500000 --seed=1723056275 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; Main: 608146 PR with paranoid_memory_checks=false: 607727 (- %0.07) PR with paranoid_memory_checks=true: 521889 (-%14.2) ``` * Memtable-only sequential scan ops/sec: ``` (for I in $(seq 1 50); do ./db_bench--benchmarks=fillseq,readseq[-X10] --write_buffer_size=268435456 --num=1000000 --seed=1723056275 2>1 | grep "\[AVG 10 runs\]"; done;) | awk '{ t += $6; c++; print; } END { printf "%.0f\n", 1.0 * t / c }'; Main: 9180077 PR with paranoid_memory_checks=false: 9536241 (+%3.8) PR with paranoid_memory_checks=true: 7653934 (-%16.6) ``` * Memtable-only reverse scan ops/sec: ``` (for I in $(seq 1 20); do ./db_bench --benchmarks=fillseq,readreverse[-X10] --write_buffer_size=268435456 --num=1000000 --seed=1723056275 2>1 | grep "\[AVG 10 runs\]"; done;) | awk '{ t += $6; c++; print; } END { printf "%.0f\n", 1.0 * t / c }'; Main: 1285719 PR with integrity_checks=false: 1431626 (+%11.3) PR with integrity_checks=true: 811031 (-%36.9) ``` The `readrandom` benchmark shows no regression. The scanning benchmarks show improvement that I can't explain. Reviewed By: pdillinger Differential Revision: D60414267 Pulled By: cbi42 fbshipit-source-id: a70b0cbeea131f1a249a5f78f9dc3a62dacfaa91
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.