google开发的Mysql5Patches

seiya

Mysql5Patches   
Patches for MySQL 5
Featured Updated Jun 24, 2011 by razv...@google.com Introduction
The code has been changed to make MySQL more manageable, available and scalable. Many problems remain to be solved to improve SMP performance. This is a good start. The v3 patch and all future patches will be published with a BSD license which applies to code we have added and changed. Original MySQL sources has a GPL license.

These have the same functionality as the MySQL 4 patches. There are several patch sets:

the v1 patch published in 2007
the v2 patch with all of our changes for MySQL 5.0.37
the v3 patch with all of our changes for MySQL 5.0.37 as of May 6, 2009. This adds global transaction IDs, row-change logging and more InnoDB SMP performance fixes.
the v4 patch as of June 1, 2009. This makes InnoDB faster on IO bound loads.
the semi-sync replication V1 patch published in 2007.
the mutex contention statistics patch for MySQL 5.1.26
the patch to improve SMP performance for MySQL 5.0.67. This has two changes:
use atomic memory instructions for the InnoDB mutex and rw-mutex. This is only done for x86 platforms that use a recent (>= 4.1) version of GCC.
disable the InnoDB memory heap. Thisi s done for all platforms.
the patch to improve SMP performance for the InnoDB 1.0.1 plugin in MySQL 5.1
disable/enable writes to InnoDB files via set global innodb_disallow_writes=(0|1)
Patch to use pthread_mutex_t instead of mutex_t for rw_lock_struct::mutex in InnoDB.
the global transaction IDs and binlog event checksums stand-alone patch extracted out of the big V3 patch and ported to mysql-5.0.68 as of May 12, 2009.
Notes on implementing synchronous replication -- MysqlSyncReplication

SmpPerformance has results for a variety of MySQL versions on 4, 8 and 16 core servers.

Feedback, Problems and Comments
Use the google-mysql-tools group

Disclaimer
We have changed a lot of code. Not all of the changes are described here and some of the changes to default behavior from new my.cnf variables can break your applications. Unless your name rhymes with Domas, it might be better to take pieces of the patch rather than try to use all of it.

The code has been tested on 32-bit and 64-bit Linux x86. We may have broken the build for other platforms.

The embedded server, --with-embedded-server, cannot be built with these changes. We have broken the build for it.

Many of the Makefile.in and Makefile.am files have been changed in the big patch because we changed InnoDB to use the top-level configure.

If you try to install the big patch, treat it like installing from a source tree.

Authors
A lot of people have contributed to this:

Wei Li
Gene Pang
Eric Rollins
Ben Handy
Justin Tolmer
Larry Zhou
Yuan Wei
Robert Banz
Chip Turner
Steve Gunn
Mark Callaghan

The v2 patch
This has many new features and a few non-features. Embedded MySQL will not work with this patch.

SqlChanges
SemiSyncReplication
InnodbSmp
NewShowStatus
NewShowInnodbStatus
NewConfiguration
UserTableMonitoring
TransactionalReplication
MysqlRoles
MysqlRateLimiting
MoreLogging
InnodbAsyncIo
FastMasterPromotion
MirroredBinlogs
InnodbSampling
NewSqlFunctions
InnodbStatus
LosslessFloatDump
MysqlHttp
InnodbIoTuning
MutexContentionStats
FastMutexes
InnodbFreeze

The v3 patch
This has many new features and a few non-features. Embedded MySQL will not work with this patch. Also, I generated the patch after running 'make distclean' so there are some files that must be regenerated after this patch is applied, including sql_yacc.cc and sql_yacc.h. By doing this, the patch diff is smaller but maybe a bit confusing. Also, I did not update any of the files in libmysqld/ that are copied from sql/.

GlobalTransactionIds
OnlineDataDrift
BatchKeyAccess
InnodbMutexContention2
BinlogEventChecksums
The v4 patch
This makes InnoDB much faster on IO bound workloads and fixes bugs in new features.

InnodbIoPerformance
Not yet released
MysqlThreadPool


来源：http://blog.chinaunix.net/space. ... blog&id=3031641