错误日志：
2016-05-30 10:28:03 23241 [ERROR] /usr/sbin/mysqld: Table './mysql/event' is marked as crashed and should be repaired
mysql库中的event表有问题需要修复
可以使用myisamchk 工具会帮助你恢复数据表的索引
[root@mysql mysql]# find / -name myisamchk
/usr/bin/myisamchk
[root@mysql  mysql]# /usr/bin/myisamchk -c -r /data/DB/mysql/mysql/event.MYI
- recovering (with sort) MyISAM-table '/data/DB/mysql/mysql/event.MYI'
Data records: 8
- Fixing index 1
重启数据库解决