A library that provides an embeddable, persistent key-value store for fast storage.
465b9103f8
Summary:
Currently the test tracks all writes in memory and
uses it for verification at the end. This has 4 problems:
(a) It needs mutex for each write to ensure in-memory update
and leveldb update are done atomically. This slows down the
benchmark.
(b) Verification phase at the end is time consuming as well
(c) Does not test batch writes or snapshots
(d) We cannot kill the test and restart multiple times in a
loop because in-memory state will be lost.
I am adding a FLAGS_multi that does MultiGet/MultiPut/MultiDelete
instead of get/put/delete to get/put/delete a group of related
keys with same values atomically. Every get retrieves the group
of keys and checks that their values are same. This does not have
the above problems but the downside is that it does less amount
of validation than the other approach.
Test Plan:
This whole this is a test! Here is a small run. I am doing larger run now.
[nponnekanti@dev902 /data/users/nponnekanti/rocksdb] ./db_stress --ops_per_thread=10000 --multi=1 --ops_per_key=25
LevelDB version : 1.5
Number of threads : 32
Ops per thread : 10000
Read percentage : 10
Delete percentage : 30
Max key : 2147483648
Num times DB reopens: 10
Num keys per lock : 4
Compression : snappy
------------------------------------------------
Creating 536870912 locks
2013/02/20-16:59:32 Starting database operations
Created bg thread 0x7f9ebcfff700
2013/02/20-16:59:37 Reopening database for the 1th time
2013/02/20-16:59:46 Reopening database for the 2th time
2013/02/20-16:59:57 Reopening database for the 3th time
2013/02/20-17:00:11 Reopening database for the 4th time
2013/02/20-17:00:25 Reopening database for the 5th time
2013/02/20-17:00:36 Reopening database for the 6th time
2013/02/20-17:00:47 Reopening database for the 7th time
2013/02/20-17:00:59 Reopening database for the 8th time
2013/02/20-17:01:10 Reopening database for the 9th time
2013/02/20-17:01:20 Reopening database for the 10th time
2013/02/20-17:01:31 Reopening database for the 11th time
2013/02/20-17:01:31 Starting verification
Stress Test : 109.125 micros/op 22191 ops/sec
: Wrote 0.00 MB (0.23 MB/sec) (59% of 32 ops)
: Deleted 10 times
2013/02/20-17:01:31 Verification successful
Revert Plan: OK
Task ID: #
Reviewers: dhruba, emayanke
Reviewed By: emayanke
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8733
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| db | ||
| doc | ||
| hdfs | ||
| helpers/memenv | ||
| include/leveldb | ||
| java | ||
| linters/src | ||
| port | ||
| scribe | ||
| snappy | ||
| table | ||
| thrift | ||
| tools | ||
| util | ||
| .arcconfig | ||
| .gitignore | ||
| build_detect_platform | ||
| build_detect_version | ||
| build_java.sh | ||
| fbcode.clang31.sh | ||
| fbcode.gcc471.sh | ||
| LICENSE | ||
| Makefile | ||
| README | ||
| README.fb | ||
| regression_build_test.sh | ||
rocksdb: A persistent key-value store for flash storage
Authors: The Facebook Database Engineering Team
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.h
include/table_builder.h
Lower-level modules that most clients probably won't use directly