A library that provides an embeddable, persistent key-value store for fast storage.
91687d70ea
Summary: Bloom filters generated by pre-7.0 releases are not read by 7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name() in https://github.com/facebook/rocksdb/issues/9590. This can severely impact read performance and read I/O on upgrade or downgrade with existing DB, but not data correctness. To fix, we go back using the old, unified name in SST metadata but (for a while anyway) recognize the aliases that could be generated by early 7.0.x releases. This unfortunately requires a public API change to avoid interfering with all the good changes from https://github.com/facebook/rocksdb/issues/9590, but the API change only affects users with custom FilterPolicy, which should be very few. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9736 Test Plan: manual Generate DBs with ``` ./db_bench.7.0 -db=/dev/shm/rocksdb.7.0 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 ``` and similar. Compare with ``` for IMPL in 6.29 7.0 fixed; do for DB in 6.29 7.0 fixed; do echo "Testing $IMPL on $DB:"; ./db_bench.$IMPL -db=/dev/shm/rocksdb.$DB -use_existing_db -readonly -bloom_bits=10 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=10 2>&1 | grep micros/op; done; done ``` Results: ``` Testing 6.29 on 6.29: readrandom : 34.381 micros/op 29085 ops/sec; 3.2 MB/s (291999 of 291999 found) Testing 6.29 on 7.0: readrandom : 190.443 micros/op 5249 ops/sec; 0.6 MB/s (52999 of 52999 found) Testing 6.29 on fixed: readrandom : 40.148 micros/op 24907 ops/sec; 2.8 MB/s (249999 of 249999 found) Testing 7.0 on 6.29: readrandom : 229.430 micros/op 4357 ops/sec; 0.5 MB/s (43999 of 43999 found) Testing 7.0 on 7.0: readrandom : 33.348 micros/op 29986 ops/sec; 3.3 MB/s (299999 of 299999 found) Testing 7.0 on fixed: readrandom : 152.734 micros/op 6546 ops/sec; 0.7 MB/s (65999 of 65999 found) Testing fixed on 6.29: readrandom : 32.024 micros/op 31224 ops/sec; 3.5 MB/s (312999 of 312999 found) Testing fixed on 7.0: readrandom : 33.990 micros/op 29390 ops/sec; 3.3 MB/s (294999 of 294999 found) Testing fixed on fixed: readrandom : 28.714 micros/op 34825 ops/sec; 3.9 MB/s (348999 of 348999 found) ``` Just paying attention to order of magnitude of ops/sec (short test durations, lots of noise), it's clear that with the fix we can read <= 6.29 & >= 7.0 at full speed, where neither 6.29 nor 7.0 can on both. And 6.29 release can properly read fixed DB at full speed. Reviewed By: siying, ajkr Differential Revision: D35057844 Pulled By: pdillinger fbshipit-source-id: a46893a6af4bf084375ebe4728066d00eb08f050 |
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| COPYING | ||
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| DEFAULT_OPTIONS_HISTORY.md | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
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| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| PLUGINS.md | ||
| python.mk | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
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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.