ERROR [http-nio-10020-exec-12] [http-nio-10020-exec-12raceId] [] [5] @@GlobalExceptionAdvice@@ | server error 
org.springframework.dao.RecoverableDataAccessException: 
### Error querying database.  Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 426 milliseconds ago.  The last packet sent successfully to the server was 0 milliseconds ago.
; Communications link failure

The last packet successfully received from the server was 426 milliseconds ago.  The last packet sent successfully to the server was 0 milliseconds ago.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 426 milliseconds ago.  The last packet sent successfully to the server was 0 milliseconds ago.

或者这样的报错

ERROR 2013 (HY000) at line 7: Lost connection to MySQL server during query

慢查询导致集群压力巨大

把100多秒的慢查询任务下线后就正常了