pt-kill 是一个优秀的kill MySQL连接的一个工具，是percona toolkit的一部分，在因为空闲连接较多导致超过最大连接数、某个有问题的sql导致mysql负载很高时，都需要将一些连接kill掉，这个工具主要就是这个用途。 [b]参数[/b] –busy-time [b]运行时间[/b] –idle-time [b]空闲时间[/b] –victims 所有匹配的连接，对应有最久的连接 –interval 间隔时间，默认30s，有点长，可以根据实际情况来调节 –print 打印出来kill掉的连接 –match-command [b]匹配当前连接的命令[/b] Query Sleep Binlog Dump Connect Delayed insert Execute Fetch Init DB Kill Prepare Processlist Quit Reset stmt Table Dump –match-state [b]匹配当前连接的状态[/b] Locked login copy to tmp table Copying to tmp table Copying to tmp table on disk Creating tmp table executing Reading from net Sending data Sorting for order Sorting result Table lock Updating –match-info [b]使用正则表达式匹配符合的sql[/b] –match-db –match-user –match-host 见名知意 [b]常用用法[/b] 杀掉空闲链接 pt-kill –match-command Sleep –idle-time 5 –host –port –interval –print –kill –victims all 杀掉运行时间超过5s的链接 pt-kill –match-command Query –busy-time 5 –host –port –interval –print –kill –victims all 杀掉匹配某个规则的正在运行的sql pt-kill –match-command Query –busy-time 5 –host –port –interval –print –kill –victims all –match-info 杀掉正在进行filesort的sql pt-kill –match-command Query –match-state “Sorting result” busy-time 5 –host –port –interval –print –kill –victims all 杀掉正在Copying to tmp table的sql pt-kill –match-command Query –match-state “Copying to tmp table” busy-time 5 –host –port –interval –print –kill –victims all