dcc6fc99f9
Summary: **Context/Summary:** - StopWatch enable stats even when `StatsLevel::kExceptTimers` is set. It's a harmless bug though since `reportTimeToHistogram()` will not report it anyway according to https://github.com/facebook/rocksdb/blob/main/include/rocksdb/statistics.h#L705 - https://github.com/facebook/rocksdb/pull/11288 should have removed logics of setting `record_read_stats = !for_compaction` as we don't differentiate `RandomAccessFileReader`'s stats behavior based on compaction or not (instead we now report stats of different IO activities including compaction to different stats). Fixing this should report more compaction related file read micros that aren't reported previously due to `for_compaction==true` Pull Request resolved: https://github.com/facebook/rocksdb/pull/11474 Test Plan: - DB bench pre vs post fix with small max_open_files Setup command `./db_ bench -db=/dev/shm/testdb/ -statistics=true -benchmarks=fillseq -key_size=32 -value_size=512 -num=5000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=true -compression_type=none -bloom_bits=3` Run command `./db_bench --open_files=1 -use_existing_db=true -db=/dev/shm/testdb2/ -statistics=true -benchmarks=compactall -key_size=32 -value_size=512 -num=5000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=true -compression_type=none -bloom_bits=3` Pre-fix ``` rocksdb.sst.read.micros P50 : 2.056175 P95 : 4.647739 P99 : 8.948475 P100 : 25.000000 COUNT : 4451 SUM : 12827 rocksdb.file.read.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.read.compaction.micros P50 : 2.057397 P95 : 4.625253 P99 : 8.749474 P100 : 25.000000 COUNT : 4382 SUM : 12608 rocksdb.file.read.db.open.micros P50 : 1.985294 P95 : 9.100000 P99 : 13.000000 P100 : 13.000000 COUNT : 69 SUM : 219 ``` Post-fix (with a higher `rocksdb.file.read.compaction.micros` count) ``` rocksdb.sst.read.micros P50 : 1.858968 P95 : 3.653086 P99 : 5.968000 P100 : 21.000000 COUNT : 3548 SUM : 9119 rocksdb.file.read.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.read.compaction.micros P50 : 1.857027 P95 : 3.627614 P99 : 5.738621 P100 : 21.000000 COUNT : 3479 SUM : 8904 rocksdb.file.read.db.open.micros P50 : 2.000000 P95 : 6.733333 P99 : 11.000000 P100 : 11.000000 COUNT : 69 SUM : 215 ``` - CI Reviewed By: ajkr Differential Revision: D46137221 Pulled By: hx235 fbshipit-source-id: e5b4ee7001af26f2ee0377bc6334f43b2a527388 |
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| db | ||
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| file | ||
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| java | ||
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| AUTHORS | ||
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| CODE_OF_CONDUCT.md | ||
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| COPYING | ||
| DEFAULT_OPTIONS_HISTORY.md | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| PLUGINS.md | ||
| README.md | ||
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| USERS.md | ||
| Vagrantfile | ||
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| rocksdb.pc.in | ||
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README.md
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.