2837008525
Summary: The first version of filter_bench has selectable key size but that size does not vary throughout a test run. This artificially favors "branchy" hash functions like the existing BloomHash, MurmurHash1, probably because of optimal return for branch prediction. This change primarily varies those key sizes from -2 to +2 bytes vs. the average selected size. We also set the default key size at 24 to better reflect our best guess of typical key size. But steadily random key sizes may not be realistic either. So this change introduces a new filter_bench option: -vary_key_size_log2_interval=n where the same key size is used 2^n times and then changes to another size. I've set the default at 5 (32 times same size) as a compromise between deployments with rather consistent vs. rather variable key sizes. On my Skylake system, the performance boost to MurmurHash1 largely lies between n=10 and n=15. Also added -vary_key_alignment (bool, now default=true), though this doesn't currently seem to matter in hash functions under consideration. This change also does a "dry run" for each testing scenario, to improve the accuracy of those numbers, as there was more difference between scenarios than expected. Subtracting gross test run times from dry run times is now also embedded in the output, because these "net" times are generally the most useful. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5933 Differential Revision: D18121683 Pulled By: pdillinger fbshipit-source-id: 3c7efee1c5661a5fe43de555e786754ddf80dc1e |
||
|---|---|---|
| buckifier | ||
| build_tools | ||
| cache | ||
| cmake | ||
| coverage | ||
| db | ||
| docs | ||
| env | ||
| examples | ||
| file | ||
| hdfs | ||
| include/rocksdb | ||
| java | ||
| logging | ||
| memory | ||
| memtable | ||
| monitoring | ||
| options | ||
| port | ||
| table | ||
| test_util | ||
| third-party | ||
| tools | ||
| trace_replay | ||
| util | ||
| utilities | ||
| .clang-format | ||
| .gitignore | ||
| .lgtm.yml | ||
| .travis.yml | ||
| .watchmanconfig | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| DEFAULT_OPTIONS_HISTORY.md | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
| TARGETS | ||
| USERS.md | ||
| Vagrantfile | ||
| WINDOWS_PORT.md | ||
| appveyor.yml | ||
| defs.bzl | ||
| issue_template.md | ||
| src.mk | ||
| thirdparty.inc | ||
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/master/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.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/
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.