A library that provides an embeddable, persistent key-value store for fast storage.
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Igor Canadi 4e91f27c3a Fix performance regression in statistics
Summary:
For some reason, D15099 caused a big performance regression: https://fburl.com/16059000

After digging a bit, I figured out that the reason was that std::atomic_uint_fast64_t was allocated in an array. When I switched from an array to vector, the QPS returned to the previous level. I'm not sure why this is happening, but this diff seems to fix the performance regression.

Test Plan: I ran the regression script, observed the performance going back to normal

Reviewers: tnovak, kailiu, haobo

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15375
2014-01-23 16:11:55 -08:00
build_tools Fix some "make format" issue 2014-01-16 14:26:51 -08:00
coverage Fix the gcov/lcov related issues 2013-08-22 17:01:06 -07:00
db Unfriending classes 2014-01-22 10:55:16 -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 Statistics code cleanup 2014-01-17 12:46:06 -08:00
linters Add google-style checker to "arc lint" 2014-01-23 15:04:12 -08:00
port Print stack trace on assertion failure 2013-12-06 17:11:09 -08:00
table Statistics code cleanup 2014-01-17 12:46:06 -08:00
tools Statistics code cleanup 2014-01-17 12:46:06 -08:00
util Fix performance regression in statistics 2014-01-23 16:11:55 -08:00
utilities Fix share_table_files condition in BackupEngine constructor. 2014-01-11 05:12:07 +09:00
.arcconfig Add google-style checker to "arc lint" 2014-01-23 15:04:12 -08:00
.clang-format A script that automatically reformat affected lines 2014-01-14 12:21:24 -08:00
.gitignore Add google-style checker to "arc lint" 2014-01-23 15:04:12 -08:00
CONTRIBUTING.md Reformat CONTRIBUTING.md with less than 80 characters. 2013-11-16 22:51:09 -08:00
INSTALL.md docs for shared library builds 2013-12-30 21:34:45 +08:00
LICENSE Add appropriate LICENSE and Copyright message. 2013-10-16 17:48:41 -07:00
Makefile Move the compilation of the shared libraries to "make release" 2014-01-14 13:54:33 -08:00
PATENTS Fix the patent format 2013-10-16 15:37:32 -07:00
README Add a pointer to the engineering design discussion forum. 2013-12-23 12:19:18 -08:00
README.fb update the latest version in README.fb to 2.7 2013-12-30 16:16:24 -08:00

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.

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