有时候需要排查mysql的信息，数据库账号密码被泄露，但无法知道哪些客户端连接过。

查看客户端连接

SELECT LEFT ( HOST, LOCATE( ':', HOST ) - 1 ) AS client_ip, COUNT(*) AS connections, AVG( TIME ) AS avg_idle_time FROM INFORMATION_SCHEMA.PROCESSLIST GROUP BY client_ip ORDER BY connections DESC;

查看慢查询是否开启

SHOW VARIABLES LIKE'slow_query_log'

查看超时时间

SHOW VARIABLES LIKE'wait_timeout'