A library that provides an embeddable, persistent key-value store for fast storage.
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Akanksha Mahajan 04b2c16f9b Fix bug in rocksdb internal automatic prefetching (#9234)
Summary:
After introducing adaptive_readahead, the original flow got
broken. Readahead size was set to 0 because of which rocksdb wasn't be
able to do automatic prefetching which it enables after seeing
sequential reads. This PR fixes it.

----------------------------------------------------------------------------------------------------

Before this patch:
b_bench -use_existing_db=true -db=/tmp/prefix_scan -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 6.27
Date:       Tue Nov 30 11:56:50 2021
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]

seekrandom   : 5356367.174 micros/op 0 ops/sec;   29.4 MB/s (23 of 23 found)

----------------------------------------------------------------------------------------------------

After the patch:
./db_bench -use_existing_db=true -db=/tmp/prefix_scan -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 6.27
Date:       Tue Nov 30 14:38:33 2021
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]
seekrandom   :  456504.277 micros/op 2 ops/sec;  359.8 MB/s (264 of 264 found)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9234

Test Plan:
Ran ./db_bench -db=/data/mysql/rocksdb/prefix_scan
-benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_d
irect_io_for_flush_and_compaction=true -target_file_size_base=16777216
and then ./db_bench -use_existing_db=true
-db=/data/mysql/rocksdb/prefix_scan -benchmarks="seekrandom"
-key_size=32 -value_siz
e=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680
-duration=120 -ops_between_duration_checks=1
 and compared the results.

Reviewed By: anand1976

Differential Revision: D32743965

Pulled By: akankshamahajan15

fbshipit-source-id: b950fba68c91963b7deb5c20acdf471bc60251f5
2021-11-30 22:53:10 -08:00
.circleci Fix some CI output (#9193) 2021-11-20 10:21:58 -08:00
.github/workflows Add (& fix) some simple source code checks (#8821) 2021-09-07 21:19:27 -07:00
buckifier Update buckify scripts (#9104) 2021-11-01 10:11:18 -07:00
build_tools More improvements to output for CircleCI (#9201) 2021-11-23 22:10:27 -08:00
cache Fix build for msvc (#9230) 2021-11-29 14:27:48 -08:00
cmake Add find_dependency() in cmake config file. (#6791) 2020-05-12 21:18:29 -07:00
coverage Remove asan_symbolize.py for internal asan build (#8737) 2021-09-07 15:39:11 -07:00
db Update WriteBatch::AssignTimestamp() and Add (#9205) 2021-11-30 22:33:00 -08:00
db_stress_tool db_stress: db_stress segmentation fault (#9219) 2021-11-30 14:56:13 -08:00
docs Misc doc fixes (#8983) 2021-10-07 11:22:17 -07:00
env Fix compile warnings (#9199) 2021-11-24 11:19:06 -08:00
examples Add (& fix) some simple source code checks (#8821) 2021-09-07 21:19:27 -07:00
file Fix bug in rocksdb internal automatic prefetching (#9234) 2021-11-30 22:53:10 -08:00
fuzz Make EventListener into a Customizable Class (#8473) 2021-07-27 07:47:02 -07:00
hdfs fix build with 'USE_HDFS' on windows (#6950) 2020-06-12 16:21:50 -07:00
include/rocksdb Update WriteBatch::AssignTimestamp() and Add (#9205) 2021-11-30 22:33:00 -08:00
java Check that newIteratorWithBase regardless of WBWI Overwrite Mode (#8134) 2021-11-18 11:53:09 -08:00
logging Use system-wide thread ID in info log lines (#9164) 2021-11-12 19:46:06 -08:00
memory Fix and detect headers with missing dependencies (#8893) 2021-09-10 10:00:26 -07:00
memtable Minor improvement to CacheReservationManager/WriteBufferManager/CompressionDictBuilding (#9139) 2021-11-05 16:13:47 -07:00
microbench Skip directory fsync for filesystem btrfs (#8903) 2021-11-03 12:21:27 -07:00
monitoring Add tiered storage related read bytes stats to Statistic (#9123) 2021-11-16 15:17:17 -08:00
options Fix GetOptionsPtr for Wrapped Customizable; Allow null options map (#9213) 2021-11-30 13:23:25 -08:00
plugin Add initial CMake support to plugin (#9214) 2021-11-30 17:16:53 -08:00
port Fix/improve 'must free heap allocations' code (#9209) 2021-11-29 10:53:52 -08:00
table Fix bug in rocksdb internal automatic prefetching (#9234) 2021-11-30 22:53:10 -08:00
test_util Support readahead during compaction for blob files (#9187) 2021-11-19 17:53:47 -08:00
third-party Add support for building on s390x platform (#8962) 2021-10-22 10:13:15 -07:00
tools Fix build for msvc (#9230) 2021-11-29 14:27:48 -08:00
trace_replay Cleanup includes in dbformat.h (#8930) 2021-09-29 04:04:40 -07:00
util Add listener API that notifies on IOError (#9177) 2021-11-18 17:11:19 -08:00
utilities Fix flaky CassandraFunctionalTest...ExpiredColumnsToTombstone (#9226) 2021-11-29 09:53:07 -08:00
.clang-format A script that automatically reformat affected lines 2014-01-14 12:21:24 -08:00
.gitignore gitignore cmake-build-* for CLion integration (#7933) 2021-02-19 13:43:15 -08:00
.lgtm.yml Create lgtm.yml for LGTM.com C/C++ analysis (#4058) 2018-06-26 12:43:04 -07:00
.travis.yml Re-enable 390x+cmake* Travis jobs (#9110) 2021-11-03 20:30:15 -07:00
.watchmanconfig Added .watchmanconfig file to rocksdb repo (#5593) 2019-07-19 15:00:33 -07:00
appveyor.yml Remove 2019 from appveyor (#7038) 2020-06-29 14:31:41 -07:00
AUTHORS Update RocksDB Authors File 2017-10-18 14:42:10 -07:00
CMakeLists.txt Add initial CMake support to plugin (#9214) 2021-11-30 17:16:53 -08:00
CODE_OF_CONDUCT.md Adopt Contributor Covenant 2019-08-29 23:21:01 -07:00
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 Make testpilot recognize that these tests have coverage instrumentation 2020-03-20 11:23:23 -07:00
DUMP_FORMAT.md First version of rocksdb_dump and rocksdb_undump. 2015-06-19 16:24:36 -07:00
HISTORY.md Update WriteBatch::AssignTimestamp() and Add (#9205) 2021-11-30 22:33:00 -08:00
INSTALL.md Update installation instructions (#8158) 2021-04-06 16:02:04 -07:00
issue_template.md Add Google Group to Issue Template 2020-01-28 14:40:37 -08:00
LANGUAGE-BINDINGS.md Update branch name to "main" in README/LANGUAGE_BINDINGS (#8727) 2021-09-01 15:26:34 -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 Add initial CMake support to plugin (#9214) 2021-11-30 17:16:53 -08:00
PLUGINS.md Add ZenFS to plugin list (#8218) 2021-04-22 11:12:40 -07:00
README.md Update branch name to "main" in README/LANGUAGE_BINDINGS (#8727) 2021-09-01 15:26:34 -07:00
ROCKSDB_LITE.md Fix some typos in comments and docs. 2018-03-08 10:27:25 -08:00
src.mk Support readahead during compaction for blob files (#9187) 2021-11-19 17:53:47 -08:00
TARGETS Support readahead during compaction for blob files (#9187) 2021-11-19 17:53:47 -08:00
thirdparty.inc Fix build jemalloc api (#5470) 2019-06-24 17:40:32 -07:00
USERS.md Update USERS.md (#8923) 2021-10-01 16:10:35 -07:00
Vagrantfile Adding CentOS 7 Vagrantfile & build script 2018-02-26 15:27:17 -08:00
WINDOWS_PORT.md Update branch name in WINDOWS_PORT.md (#8745) 2021-09-01 19:26:39 -07:00

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

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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.

Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/ and https://rocksdb.slack.com/

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.