故障排查
1 找到正处于open状态的表
show open tables where in_use >=1;

2 找到引发故障的慢查询
① 找到阻塞flush tables的慢查询

SELECT * FROM information_schema.PROCESSLIST

WHERE info IS NOT NULL

AND state NOT LIKE ‘Waiting for table flush’

AND info NOT LIKE ‘SELECT * FROM information_schema.PROCESSLIST%’

AND INFO LIKE ‘%处于打开状态的表名%’

ORDER BY TIME DESC

② 找到flush tables慢查询

SELECT * FROM information_schema.PROCESSLIST

WHERE info LIKE ‘%flush tables%’

AND info NOT LIKE ‘SELECT * FROM information_schema.PROCESSLIST%’

3 故障处理
杀掉2 步骤中找到的两个慢查询

kill id;