Seems a logrotate script / cron entry caused mysql to shutdown on integration-slave-trusty-1001
/var/log/mysql/error.log.1.gz
160722 6:40:21 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead. 160722 6:40:21 [Note] Plugin 'FEDERATED' is disabled. 160722 6:40:21 InnoDB: The InnoDB memory heap is disabled 160722 6:40:21 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160722 6:40:21 InnoDB: Compressed tables use zlib 1.2.8 160722 6:40:21 InnoDB: Using Linux native AIO 160722 6:40:21 InnoDB: Initializing buffer pool, size = 128.0M 160722 6:40:21 InnoDB: Completed initialization of buffer pool 160722 6:40:21 InnoDB: highest supported file format is Barracuda. 160722 6:40:21 InnoDB: Waiting for the background threads to start 160722 6:40:22 InnoDB: 5.5.50 started; log sequence number 46210678922 160722 6:40:22 InnoDB: Starting shutdown... 160722 6:40:23 InnoDB: Shutdown completed; log sequence number 46210678922 160722 6:40:23 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead. 160722 6:40:23 [Note] Plugin 'FEDERATED' is disabled. 160722 6:40:23 InnoDB: The InnoDB memory heap is disabled 160722 6:40:23 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160722 6:40:23 InnoDB: Compressed tables use zlib 1.2.8 160722 6:40:23 InnoDB: Using Linux native AIO 160722 6:40:23 InnoDB: Initializing buffer pool, size = 128.0M 160722 6:40:23 InnoDB: Completed initialization of buffer pool 160722 6:40:23 InnoDB: highest supported file format is Barracuda. 160722 6:40:23 InnoDB: Waiting for the background threads to start 160722 6:40:24 InnoDB: 5.5.50 started; log sequence number 46210678922 ERROR: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ALTER TABLE user ADD column Show_view_priv enum('N','Y') CHARACTER SET utf8 NOT ' at line 1 160722 6:40:24 [ERROR] Aborting 160722 6:40:24 InnoDB: Starting shutdown... 160722 6:40:25 InnoDB: Shutdown completed; log sequence number 46210678922 160722 6:40:25 [Note] /usr/sbin/mysqld: Shutdown complete
That is due to the auto upgrade from /var/log/dpkg.log
2016-07-22 06:40:20 status installed mysql-server-core-5.5:amd64 5.5.50-0ubuntu0.14.04.1