A library that provides an embeddable, persistent key-value store for fast storage.
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Igor Canadi 1fdb3f7dc6 [RocksDB] Optimize locking for Get
Summary:
Instead of locking and saving a DB state, we can cache a DB state and update it only when it changes. This change reduces lock contention and speeds up read operations on the DB.

Performance improvements are substantial, although there is some cost in no-read workloads. I ran the regression tests on my devserver and here are the numbers:

  overwrite                    56345  ->   63001
  fillseq                      193730 ->  185296
  readrandom                   771301 -> 1219803 (58% improvement!)
  readrandom_smallblockcache   677609 ->  862850
  readrandom_memtable_sst      710440 -> 1109223
  readrandom_fillunique_random 221589 ->  247869
  memtablefillrandom           105286 ->   92643
  memtablereadrandom           763033 -> 1288862

Test Plan:
make asan_check
I am also running db_stress

Reviewers: dhruba, haobo, sdong, kailiu

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14679
2013-12-20 09:57:58 -08:00
build_tools Add readrandom with both memtable and sst regression test 2013-12-11 13:51:20 -08:00
coverage Fix the gcov/lcov related issues 2013-08-22 17:01:06 -07:00
db [RocksDB] Optimize locking for Get 2013-12-20 09:57:58 -08:00
doc Fix typo. 2013-11-28 03:57:16 +09:00
hdfs Add appropriate LICENSE and Copyright message. 2013-10-16 17:48:41 -07:00
helpers/memenv Change Function names from Compaction->Flush When they really mean Flush 2013-10-14 15:12:15 -07:00
include C bindings: add a bunch of the newer options 2013-12-15 13:47:06 -08:00
linters/src fixing linters. 2012-12-14 14:05:27 -08:00
port Print stack trace on assertion failure 2013-12-06 17:11:09 -08:00
table Fix #26 by putting the implementation of CreateDBStatistics() to a cc file 2013-12-05 22:29:03 -08:00
tools Killing Transform Rep 2013-12-03 12:42:15 -08:00
util [RocksDB perf] Cache speedup 2013-12-11 08:33:29 -08:00
utilities Remove .DS_Store files. 2013-12-17 06:00:47 +01:00
.arcconfig Enable linting in arc. 2013-02-01 11:34:25 -08:00
.gitignore Remove invalid items in .gitignore 2013-11-05 21:04:22 -08:00
CONTRIBUTING.md Reformat CONTRIBUTING.md with less than 80 characters. 2013-11-16 22:51:09 -08:00
INSTALL.md Cleaning up INSTALL.md -- there were two occurrences of gflags 2013-12-02 06:48:23 -08:00
LICENSE Add appropriate LICENSE and Copyright message. 2013-10-16 17:48:41 -07:00
Makefile Reorder tests 2013-12-18 13:37:06 -08:00
PATENTS Fix the patent format 2013-10-16 15:37:32 -07:00
README Removing reference to doc/impl.html 2013-12-02 11:51:20 -08:00
README.fb Update the latest rocksdb version 2013-10-22 14:49:44 -07:00

rocksdb: A persistent key-value store for flash storage
Authors: * The Facebook Database Engineering Team
         * Build 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 an 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.

The core of this code has been derived from open-source leveldb.

The code under this directory implements a system for maintaining a
persistent key/value store.

See doc/index.html and github wiki (https://github.com/facebook/rocksdb/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.

Guide to header files:

include/rocksdb/db.h
    Main interface to the DB: Start here

include/rocksdb/options.h
    Control over the behavior of an entire database, and also
    control over the behavior of individual reads and writes.

include/rocksdb/comparator.h
    Abstraction for user-specified comparison function.  If you want
    just bytewise comparison of keys, you can use the default comparator,
    but clients can write their own comparator implementations if they
    want custom ordering (e.g. to handle different character
    encodings, etc.)

include/rocksdb/iterator.h
    Interface for iterating over data. You can get an iterator
    from a DB object.

include/rocksdb/write_batch.h
    Interface for atomically applying multiple updates to a database.

include/rocksdb/slice.h
    A simple module for maintaining a pointer and a length into some
    other byte array.

include/rocksdb/status.h
    Status is returned from many of the public interfaces and is used
    to report success and various kinds of errors.

include/rocksdb/env.h
    Abstraction of the OS environment.  A posix implementation of
    this interface is in util/env_posix.cc

include/rocksdb/table_builder.h
    Lower-level modules that most clients probably won't use directly

include/rocksdb/cache.h
    An API for the block cache.

include/rocksdb/compaction_filter.h
    An API for a application filter invoked on every compaction.

include/rocksdb/filter_policy.h
    An API for configuring a bloom filter.

include/rocksdb/memtablerep.h
    An API for implementing a memtable.

include/rocksdb/statistics.h
    An API to retrieve various database statistics.

include/rocksdb/transaction_log.h
    An API to retrieve transaction logs from a database.