A library that provides an embeddable, persistent key-value store for fast storage.
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Siying Dong 0bb555630f Consolidate hash function used for non-persistent data in a new function (#5155)
Summary:
Create new function NPHash64() and GetSliceNPHash64(), which are currently
implemented using murmurhash.
Replace the current direct call of murmurhash() to use the new functions
if the hash results are not used in on-disk format.
This will make it easier to try out or switch to alternative functions
in the uses where data format compatibility doesn't need to be considered.
This part shouldn't have any performance impact.

Also, the sharded cache hash function is changed to the new format, because
it falls into this categoery. It doesn't show visible performance impact
in db_bench results. CPU showed by perf is increased from about 0.2% to 0.4%
in an extreme benchmark setting (4KB blocks, no-compression, everything
cached in block cache). We've known that the current hash function used,
our own Hash() has serious hash quality problem. It can generate a lots of
conflicts with similar input. In this use case, it means extra lock contention
for reads from the same file. This slight CPU regression is worthy to me
to counter the potential bad performance with hot keys. And hopefully this
will get further improved in the future with a better hash function.

cache_test's condition is relaxed a little bit to. The new hash is slightly
more skewed in this use case, but I manually checked the data and see
the hash results are still in a reasonable range.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5155

Differential Revision: D14834821

Pulled By: siying

fbshipit-source-id: ec9a2c0a2f8ae4b54d08b13a5c2e9cc97aa80cb5
2019-04-08 13:32:06 -07:00
buckifier Add load statements to rocksdb TARGETS files 2019-02-13 14:08:21 -08:00
build_tools Fix db_stress for custom env (#5122) 2019-03-28 19:20:27 -07:00
cache Consolidate hash function used for non-persistent data in a new function (#5155) 2019-04-08 13:32:06 -07:00
cmake Make FindZLIB consistent with official definitions (#4823) 2019-01-02 12:49:57 -08:00
coverage Remove unused imports, from python scripts. (#4057) 2018-06-26 12:43:04 -07:00
db Consolidate hash function used for non-persistent data in a new function (#5155) 2019-04-08 13:32:06 -07:00
docs Blog post for format_version=4 2019-03-08 16:49:30 -08:00
env Fix db_stress for custom env (#5122) 2019-03-28 19:20:27 -07:00
examples Support for single-primary, multi-secondary instances (#4899) 2019-03-26 16:45:31 -07:00
hdfs Fix db_stress for custom env (#5122) 2019-03-28 19:20:27 -07:00
include/rocksdb Expose DB methods to lock and unlock the WAL (#5146) 2019-04-06 06:40:36 -07:00
java Document the interaction between disableWAL and BackupEngine (#5071) 2019-03-19 14:58:14 -07:00
memtable Consolidate hash function used for non-persistent data in a new function (#5155) 2019-04-08 13:32:06 -07:00
monitoring Add a missing define to monitoring/iostats_context_imp.h (#5136) 2019-04-02 11:56:18 -07:00
options Fix many bugs in log statement arguments (#5089) 2019-04-04 12:12:11 -07:00
port #5145 , rename port/dirent.h to port/port_dirent.h to avoid compile err when use port dir as header dir output (#5152) 2019-04-04 11:38:19 -07:00
table Evict the uncompression dictionary from the block cache upon table close (#5150) 2019-04-04 16:21:12 -07:00
third-party/gtest-1.7.0/fused-src/gtest remove bundled but unused fbson library (#5108) 2019-03-26 16:37:52 -07:00
tools #5145 , rename port/dirent.h to port/port_dirent.h to avoid compile err when use port dir as header dir output (#5152) 2019-04-04 11:38:19 -07:00
util Consolidate hash function used for non-persistent data in a new function (#5155) 2019-04-08 13:32:06 -07:00
utilities Consolidate hash function used for non-persistent data in a new function (#5155) 2019-04-08 13:32:06 -07:00
.clang-format A script that automatically reformat affected lines 2014-01-14 12:21:24 -08:00
.gitignore RocksDB Trace Analyzer (#4091) 2018-08-13 11:44:02 -07:00
.lgtm.yml Create lgtm.yml for LGTM.com C/C++ analysis (#4058) 2018-06-26 12:43:04 -07:00
.travis.yml Fix printf formatting on MacOS (#4533) 2018-10-19 14:46:09 -07:00
appveyor.yml Add RocksJava build to AppVeyor 2019-01-03 10:44:44 -08:00
AUTHORS Update RocksDB Authors File 2017-10-18 14:42:10 -07:00
CMakeLists.txt Support for single-primary, multi-secondary instances (#4899) 2019-03-26 16:45:31 -07:00
CODE_OF_CONDUCT.md Add Code of Conduct 2017-12-05 18:42:35 -08:00
CONTRIBUTING.md Add Code of Conduct 2017-12-05 18:42:35 -08:00
COPYING Add GPLv2 as an alternative license. 2017-04-27 18:06:12 -07:00
DEFAULT_OPTIONS_HISTORY.md options.delayed_write_rate use the rate of rate_limiter by default. 2017-05-24 09:58:24 -07:00
defs.bzl [sync fix] Add defs.bzl 2019-02-28 11:35:30 -08:00
DUMP_FORMAT.md First version of rocksdb_dump and rocksdb_undump. 2015-06-19 16:24:36 -07:00
HISTORY.md Mark logs with prepare in PreReleaseCallback (#5121) 2019-04-02 15:17:47 -07:00
INSTALL.md Update the version of the dependencies used by the RocksJava static build (#4761) 2018-12-18 20:25:43 -08:00
issue_template.md Add a template for issues 2017-09-29 11:41:28 -07:00
LANGUAGE-BINDINGS.md LANGUAGE-BINDINGS.md: mention python-rocksdb 2019-03-20 11:10:48 -07:00
LICENSE.Apache Change RocksDB License 2017-07-15 16:11:23 -07:00
LICENSE.leveldb Add back the LevelDB license file 2017-07-16 18:42:18 -07:00
Makefile Support for single-primary, multi-secondary instances (#4899) 2019-03-26 16:45:31 -07:00
README.md Add LevelDB repository link in the Readme 2019-04-01 18:19:09 -07:00
ROCKSDB_LITE.md Fix some typos in comments and docs. 2018-03-08 10:27:25 -08:00
src.mk Support for single-primary, multi-secondary instances (#4899) 2019-03-26 16:45:31 -07:00
TARGETS Support for single-primary, multi-secondary instances (#4899) 2019-03-26 16:45:31 -07:00
thirdparty.inc Provide a way to override windows memory allocator with jemalloc for ZSTD 2018-06-04 12:12:48 -07:00
USERS.md Adding IOTA Foundation to USERS.MD (#4436) 2018-10-02 10:03:46 -07:00
Vagrantfile Adding CentOS 7 Vagrantfile & build script 2018-02-26 15:27:17 -08:00
WINDOWS_PORT.md #5145 , rename port/dirent.h to port/port_dirent.h to avoid compile err when use port dir as header dir output (#5152) 2019-04-04 11:38:19 -07:00

RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

Linux/Mac Build Status Windows Build status PPC64le Build Status

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 specially 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.