63a284a6ad
Summary: …in order This fixes https://github.com/facebook/rocksdb/issues/9650 For db_bench --benchmarks=fillseq --num_multi_db=X it loads databases in sequence rather than randomly choosing a database per Put. The benefits are: 1) avoids long delays between flushing memtables 2) avoids flushing memtables for all of them at the same point in time 3) puts same number of keys per database so that query tests will find keys as expected Pull Request resolved: https://github.com/facebook/rocksdb/pull/9713 Test Plan: Using db_bench.1 without the change and db_bench.2 with the change: for i in 1 2; do rm -rf /data/m/rx/* ; time ./db_bench.$i --db=/data/m/rx --benchmarks=fillseq --num_multi_db=4 --num=10000000; du -hs /data/m/rx ; done --- without the change fillseq : 3.188 micros/op 313682 ops/sec; 34.7 MB/s real 2m7.787s user 1m52.776s sys 0m46.549s 2.7G /data/m/rx --- with the change fillseq : 3.149 micros/op 317563 ops/sec; 35.1 MB/s real 2m6.196s user 1m51.482s sys 0m46.003s 2.7G /data/m/rx Also, temporarily added a printf to confirm that the code switches to the next database at the right time ZZ switch to db 1 at 10000000 ZZ switch to db 2 at 20000000 ZZ switch to db 3 at 30000000 for i in 1 2; do rm -rf /data/m/rx/* ; time ./db_bench.$i --db=/data/m/rx --benchmarks=fillseq,readrandom --num_multi_db=4 --num=100000; du -hs /data/m/rx ; done --- without the change, smaller database, note that not all keys are found by readrandom because databases have < and > --num keys fillseq : 3.176 micros/op 314805 ops/sec; 34.8 MB/s readrandom : 1.913 micros/op 522616 ops/sec; 57.7 MB/s (99873 of 100000 found) --- with the change, smaller database, note that all keys are found by readrandom fillseq : 3.110 micros/op 321566 ops/sec; 35.6 MB/s readrandom : 1.714 micros/op 583257 ops/sec; 64.5 MB/s (100000 of 100000 found) Reviewed By: jay-zhuang Differential Revision: D35030168 Pulled By: mdcallag fbshipit-source-id: 2a18c4ec571d954cf5a57b00a11802a3608823ee
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.