MYSQL 主从恢复锁表后, 处理SQL 线程锁解决.

1. 按客户端 IP 分组，看哪个客户端的链接数最多
select client_ip,count(client_ip) as client_num from (select substring_index(host,':' ,1) as client_ip from information_schema.processlist ) as connect_info group by client_ip order by client_num desc;

2. 查看正在执行的线程，并按 Time 倒排序，看看有没有执行时间特别长的线程
select * from information_schema.processlist where Command != 'Sleep' order by Time desc;

3. 查询当前运行的所有事物: 
select * from information_schema.innodb_trx \G

4. 清理掉所有状态不是Sleep且等待时间待遇5分钟的sql进程, 一般都是Query: “Waiting for global read lock”
select concat('kill ', id, ';') from information_schema.processlist where Command != 'Sleep' and Time > 300 order by Time desc;