rocksdb

fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph

Peter Dillinger 249eff0f30 Stats for redundant insertions into block cache (#6681 ) Summary: Since read threads do not coordinate on loading data into block cache, two threads between Lookup and Insert can end up loading and inserting the same data. This is particularly concerning with cache_index_and_filter_blocks since those are hot and more likely to be race targets if ejected from (or not pre-populated in) the cache. Particularly with moves toward disaggregated / network storage, the cost of redundant retrieval might be high, and we should at least have some hard statistics from which we can estimate impact. Example with full filter thrashing "cliff": $ ./db_bench --benchmarks=fillrandom --num=15000000 --cache_index_and_filter_blocks -bloom_bits=10 ... $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((130 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 \| egrep '^rocksdb.block.cache.(.add\|.redundant)' \| grep -v compress \| sort rocksdb.block.cache.add COUNT : 14181 rocksdb.block.cache.add.failures COUNT : 0 rocksdb.block.cache.add.redundant COUNT : 476 rocksdb.block.cache.data.add COUNT : 12749 rocksdb.block.cache.data.add.redundant COUNT : 18 rocksdb.block.cache.filter.add COUNT : 1003 rocksdb.block.cache.filter.add.redundant COUNT : 217 rocksdb.block.cache.index.add COUNT : 429 rocksdb.block.cache.index.add.redundant COUNT : 241 $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((120 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 \| egrep '^rocksdb.block.cache.(.add\|.redundant)' \| grep -v compress \| sort rocksdb.block.cache.add COUNT : 1182223 rocksdb.block.cache.add.failures COUNT : 0 rocksdb.block.cache.add.redundant COUNT : 302728 rocksdb.block.cache.data.add COUNT : 31425 rocksdb.block.cache.data.add.redundant COUNT : 12 rocksdb.block.cache.filter.add COUNT : 795455 rocksdb.block.cache.filter.add.redundant COUNT : 130238 rocksdb.block.cache.index.add COUNT : 355343 rocksdb.block.cache.index.add.redundant COUNT : 172478 Pull Request resolved: https://github.com/facebook/rocksdb/pull/6681 Test Plan: Some manual testing (above) and unit test covering key metrics is included Reviewed By: ltamasi Differential Revision: D21134113 Pulled By: pdillinger fbshipit-source-id: c11497b5f00f4ffdfe919823904e52d0a1a91d87		5 years ago
.circleci	Migrate AppVeyor to CircleCI (#6518 )	5 years ago
buckifier	Update buckifier to unblock future internal release (#6726 )	5 years ago
build_tools	C++20 compatibility (#6697 )	5 years ago
cache	Stats for redundant insertions into block cache (#6681 )	5 years ago
cmake	C++20 compatibility (#6697 )	5 years ago
coverage	Update a few scripts to be python3 compatible (#6525 )	5 years ago
db	Stats for redundant insertions into block cache (#6681 )	5 years ago
db_stress_tool	Disable O_DIRECT in stress test when db directory does not support direct IO (#6727 )	5 years ago
docs	Log warning for high bits/key in legacy Bloom filter (#6312 )	5 years ago
env	Fix unused variable of r in release mode (#6750 )	5 years ago
examples	Add a ConfigOptions for use in comparing objects and converting to/from strings (#6389 )	5 years ago
file	Reduce memory copies when fetching and uncompressing blocks from SST files (#6689 )	5 years ago
hdfs	Add IsDirectory() to Env and FS (#6711 )	5 years ago
include/rocksdb	Stats for redundant insertions into block cache (#6681 )	5 years ago
java	Add a ConfigOptions for use in comparing objects and converting to/from strings (#6389 )	5 years ago
logging	Fix info log source file display length (#5824 )	5 years ago
memory	C++20 compatibility (#6697 )	5 years ago
memtable	C++20 compatibility (#6697 )	5 years ago
monitoring	Stats for redundant insertions into block cache (#6681 )	5 years ago
options	Reduce memory copies when fetching and uncompressing blocks from SST files (#6689 )	5 years ago
port	C++20 compatibility (#6697 )	5 years ago
table	Stats for redundant insertions into block cache (#6681 )	5 years ago
test_util	Disable O_DIRECT in stress test when db directory does not support direct IO (#6727 )	5 years ago
third-party	C++20 compatibility (#6697 )	5 years ago
tools	Allow sst_dump to check size of different compression levels and report time (#6634 )	5 years ago
trace_replay	Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433 )	5 years ago
util	Stats for redundant insertions into block cache (#6681 )	5 years ago
utilities	Add a ConfigOptions for use in comparing objects and converting to/from strings (#6389 )	5 years ago
.clang-format	A script that automatically reformat affected lines	11 years ago
.gitignore	Separate timestamp related test from db_basic_test (#6516 )	5 years ago
.lgtm.yml	Create lgtm.yml for LGTM.com C/C++ analysis (#4058 )	6 years ago
.travis.yml	C++20 compatibility (#6697 )	5 years ago
.watchmanconfig	Added .watchmanconfig file to rocksdb repo (#5593 )	5 years ago
AUTHORS	Update RocksDB Authors File	7 years ago
CMakeLists.txt	Reduce memory copies when fetching and uncompressing blocks from SST files (#6689 )	5 years ago
CODE_OF_CONDUCT.md	Adopt Contributor Covenant	5 years ago
CONTRIBUTING.md	Add Code of Conduct	7 years ago
COPYING	Add GPLv2 as an alternative license.	8 years ago
DEFAULT_OPTIONS_HISTORY.md	options.delayed_write_rate use the rate of rate_limiter by default.	8 years ago
DUMP_FORMAT.md	First version of rocksdb_dump and rocksdb_undump.	10 years ago
HISTORY.md	Allow sst_dump to check size of different compression levels and report time (#6634 )	5 years ago
INSTALL.md	Update the version of the dependencies used by the RocksJava static build (#4761 )	6 years ago
LANGUAGE-BINDINGS.md	LANGUAGE-BINDINGS.md: mention python-rocksdb	6 years ago
LICENSE.Apache	Change RocksDB License	7 years ago
LICENSE.leveldb	Add back the LevelDB license file	7 years ago
Makefile	Understand common build variables passed as make variables (#6740 )	5 years ago
README.md	Replaced some words (#5877 )	5 years ago
ROCKSDB_LITE.md	Fix some typos in comments and docs.	7 years ago
TARGETS	Update buckifier to unblock future internal release (#6726 )	5 years ago
USERS.md	add user nebula (#6271 )	5 years ago
Vagrantfile	Adding CentOS 7 Vagrantfile & build script	7 years ago
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 )	6 years ago
appveyor.yml	C++20 compatibility (#6697 )	5 years ago
defs.bzl	Make testpilot recognize that these tests have coverage instrumentation	5 years ago
issue_template.md	Add Google Group to Issue Template	5 years ago
src.mk	Reduce memory copies when fetching and uncompressing blocks from SST files (#6689 )	5 years ago
thirdparty.inc	Fix build jemalloc api (#5470 )	5 years ago

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.