apache和mysql无故停止，请求解决方案。谢谢

Question

google一下找不到答案。
网站原来是好好的，服务器里面大概自己做了600多个站，以前一切都正常。
最近几天服务器老出问题，不是apache自动停止，就是mysql连接不上。重启一下服务又好，
mysql具体错误如下：
110411 02:30:16 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
110411 02:45:18 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
110411  2:45:19 [Warning] '--default-character-set' is deprecated and will be removed in a future release. Please use '--character-set-server' instead.
110411  2:45:19 [Note] Plugin 'ndbcluster' is disabled.
/usr/libexec/mysqld: Table 'mysql.plugin' doesn't exist
110411  2:45:19 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
110411  2:45:19  InnoDB: Initializing buffer pool, size = 8.0M
110411  2:45:19  InnoDB: Completed initialization of buffer pool
110411  2:45:20  InnoDB: Started; log sequence number 0 43665
110411  2:45:20 [ERROR] Can't open and lock privilege tables: Table 'mysql.servers' doesn't exist
110411  2:45:20 [ERROR] Column count of mysql.db is wrong. Expected 22, found 20. Created with MySQL 50077, now running 50156. Please use mysql_upgrade to fix this error.
110411  2:45:20 [ERROR] mysql.user has no `Event_priv` column at position 29
110411  2:45:20 [ERROR] Cannot open mysql.event
110411  2:45:20 [ERROR] Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.
110411  2:45:20 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.1.56'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Source distribution

apache具体错误如下：
[Mon Apr 11 23:53:40 2011] [warn] RSA server certificate CommonName (CN) `localhost.localdomain' does NOT match server name!?
[Tue Apr 12 12:20:57 2011] [warn] [client 173.242.125.196] mod_include: Options +Includes (or IncludesNoExec) wasn't set, INCLUDES filter removed