Percona_Toolkit
Percona Toolkit 的简介：（来自官方的简介）
Percona Toolkit for MySQL is a collection for advanced command-line tools userd by Percona MySQL staff to perform a variety of MySQL server and system tasks that are too difficult or complex to perform manually, including:
-Verify master and replica data consistency
-Efficiently archive rows
-Find duplicate indexes
-Summarize MySQL servers
-Analyze queries from logs and tcpdump
-Collect vital system information when problems occur
Percona Toolkit 的系统要求：(或者称为环境变量的要求)
Most tools require:
* Perl v5.8 or newer
* Bash v3 or newer
* Core Perl modules like Times:HiRes
Tools that connect to MySQL require:
* Perl modules DBI and DBD::mysql and perl-IO-Socket-SSL
* MySQL 5.0 or newer
Percona Toolkit is only tested on UNIX system,primary Debian and Red Hat derivatives;other operating systems are not supperted.
注释：rpm安装Percona Toolkit 具体需安装perl的那些模块根据自己的系统环境或者参考安装过程碰到的错误去决定需安装那些。
Percona Toolkit 的安装：
1:下载percona toolkit的包：（可以是源码包，或者RPM）
访问：http://www.percona.com/software/percona-toolkit/ 下载最新稳定的版本。也可以如下命令行的方式下载最新版本。
wget percona.com/get/percona-toolkit.tar.gz
wget percona.com/get/percona-toolkit.rpm
2：安装于Perl相关的模块
yum install perl-DBI
yum install perl-DBD-MySQL
yum install perl-Time-HiRes
yum install perl-IO-Socket-SSL
3: 安装Percona Toolkit
rpm -Uvh percona-toolkit-2.2.1-2.noarch.rpm
OK，就这么简单，安装完毕。
特别说明：
本机为：Linux mysql.example.com 2.6.18-308.el5 #1 SMP Tue Feb 21 20:06:06 EST 2012 x86_64 x86_64 x86_64 GNU/Linux
安装错误：
在yum install perl-DBD-MySQL时，出现如下错误信息
---> Package perl-DBD-MySQL.x86_64 0:3.0007-2.el5 set to be updated
--> Processing Dependency: libmysqlclient.so.15(libmysqlclient_15)(64bit) for package: perl-DBD-MySQL
--> Processing Dependency: libmysqlclient.so.15()(64bit) for package: perl-DBD-MySQL
--> Running transaction check
---> Package mysql.x86_64 0:5.0.95-5.el5_9 set to be updated
--> Processing Conflict: mysql conflicts MySQL
--> Finished Dependency Resolution
mysql-5.0.95-5.el5_9.x86_64 from updates has depsolving problems
--> mysql conflicts with MySQL-server
Error: mysql conflicts with MySQL-server
由于我安装的是5.5.xx的MySQL版本，而系统自带的是5.0xx版本的，而libmysqlclient.so.15是由5.0版本提供的，所以就出错了。如果你的系统是centos6.X系列的，MySQL自带的为5.1以上，可能不会出现这个问题了。解决方案如下：
rpm -Uvh MySQL-shared-compat-5.5.31-1.rhel5.x86_64.rpm
MySQL-shared-compat为客户端的libraries ，向下兼容。
在yum install perl-DBD-MySQL就没有问题了。
