A library that provides an embeddable, persistent key-value store for fast storage.
9700677a2b
Summary: Currently, when a certain number of level0 files (level0_slowdown_writes_trigger) are present, RocksDB will slow down each write by 1ms. There is a second limit of level0 files at which RocksDB will stop writes altogether (level0_stop_writes_trigger). This patch enables the user to supply a third parameter specifying the number of files at which Rocks will start slowing down writes (level0_start_slowdown_writes). When this number is reached, Rocks will slow down writes as a quadratic function of level0_slowdown_writes_trigger - num_level0_files. For some workloads, this improves latency and throughput. I will post some stats momentarily in https://our.intern.facebook.com/intern/tasks/?t=2613384. Test Plan: make -j32 check ./db_stress ./db_bench Reviewers: dhruba, haobo, MarkCallaghan, xjin Reviewed By: xjin CC: leveldb, xjin, zshao Differential Revision: https://reviews.facebook.net/D11859 |
||
---|---|---|
db | ||
doc | ||
hdfs | ||
helpers/memenv | ||
include | ||
java | ||
linters/src | ||
port | ||
scribe | ||
snappy | ||
table | ||
thrift | ||
tools | ||
util | ||
utilities | ||
VALGRIND_LOGS | ||
.arcconfig | ||
.gitignore | ||
build_detect_platform | ||
build_detect_version | ||
build_java.sh | ||
e | ||
fbcode.clang31.sh | ||
fbcode.gcc471.sh | ||
LICENSE | ||
Makefile | ||
README | ||
README.fb | ||
regression_build_test.sh | ||
valgrind_test.sh |
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-Stuctured-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 for more explanation. See doc/impl.html for a brief overview of the implementation. The public interface is in include/*.h. 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/db.h Main interface to the DB: Start here include/options.h Control over the behavior of an entire database, and also control over the behavior of individual reads and writes. include/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/iterator.h Interface for iterating over data. You can get an iterator from a DB object. include/write_batch.h Interface for atomically applying multiple updates to a database. include/slice.h A simple module for maintaining a pointer and a length into some other byte array. include/status.h Status is returned from many of the public interfaces and is used to report success and various kinds of errors. include/env.h Abstraction of the OS environment. A posix implementation of this interface is in util/env_posix.cc include/table_builder.h Lower-level modules that most clients probably won't use directly include/cache.h An API for the block cache. include/compaction_filter.h An API for a application filter invoked on every compaction. include/filter_policy.h An API for configuring a bloom filter. include/memtablerep.h An API for implementing a memtable. include/statistics.h An API to retrieve various database statistics. include/transaction_log_iterator.h An API to retrieve transaction logs from a database.