MySQL 启动故障 处理 小记

昨天启动MySQL时，就不太正常，要多重启几次，不过能启动，也就没放在心上，今天测试测试又出现了问题，MySQL 启动正常，但是无法关闭：

[root@rac2 mysql]# service mysql stop

MySQL server PID file could not befound! [FAILED]

[root@rac2 mysql]# ./mysql.server stop

MySQL server PID file could not befound! [FAILED]

这里提示的PID 文件指：/var/lib/mysql/rac2.pid，该文件和/var/lib/mysql/mysql.sock 文件一样，仅在MySQL 运行时存在，后来的验证如下：

[root@rac2 lib]# ls /var/lib/mysql/rac2.pid

/var/lib/mysql/rac2.pid

[root@rac2 lib]# service mysql stop

Shutting down MySQL. [ OK ]

[root@rac2 lib]# ls /var/lib/mysql/rac2.pid

ls: /var/lib/mysql/rac2.pid: No such fileor directory

所以当我的MySQL 运行正常时，应该是存在这个文件的，google的一个说法是my.cnf 参数文件的basedir 参数错误，注释掉这个参数即可，但是我都没有设过这个参数，所以和这个应该没有关系。

查看了一下默认值：

mysql> show variables like '%basedir%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| basedir | /usr |

+---------------+-------+

1 row in set (0.00 sec)

[root@rac2 ~]# ps -ef|grep mysql

root 2161 1 0 09:38 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe--datadir=/var/lib/mysql --pid-file=/var/lib/mysql/rac2.pid

mysql 2418 2161 0 09:38 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr--datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql--log-error=/var/lib/mysql/rac2.err --pid-file=/var/lib/mysql/rac2.pid--socket=/var/lib/mysql/mysql.sock --port=3306

root 3628 3596 0 09:57 pts/1 00:00:00 grep mysql

--log信息

[root@rac2 ~]#cat /var/lib/mysql/rac2.err

111129 9:38:49 [Note] Plugin 'FEDERATED' is disabled.

111129 9:38:49 InnoDB: The InnoDB memory heap is disabled

111129 9:38:49 InnoDB: Mutexes and rw_locks use GCC atomic builtins

111129 9:38:49 InnoDB: Compressed tables use zlib 1.2.3

111129 9:38:49 InnoDB: Using Linux native AIO

111129 9:38:49 InnoDB: Initializing buffer pool, size = 128.0M

111129 9:38:50 InnoDB: Completed initialization of buffer pool

111129 9:38:50 InnoDB: highest supported file format is Barracuda.

111129 9:38:50 InnoDB: Waiting for thebackground threads to start

111129 9:38:51 InnoDB: 1.1.8 started; log sequence number 1605950

111129 9:38:52 [Note] Event Scheduler: Loaded 0 events

111129 9:38:52 [Note] /usr/sbin/mysqld: ready for connections.

Version: '5.5.15-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL)

111129 10:50:36 mysqld_safe Starting mysqlddaemon with databases from /var/lib/mysql

111129 10:50:37 [Note] Plugin 'FEDERATED'is disabled.

111129 10:50:37 InnoDB: The InnoDB memoryheap is disabled

111129 10:50:37 InnoDB: Mutexes andrw_locks use GCC atomic builtins

111129 10:50:37 InnoDB: Compressed tablesuse zlib 1.2.3

111129 10:50:37 InnoDB: Using Linux nativeAIO

111129 10:50:37 InnoDB: Initializing bufferpool, size = 128.0M

111129 10:50:37 InnoDB: Completedinitialization of buffer pool

InnoDB: Unable to lock ./ibdata1, error: 11

InnoDB: Check that you do not already haveanother mysqld process

InnoDB: using the same InnoDB data or logfiles.

111129 10:50:37 InnoDB: Retrying to lock the first data file

InnoDB: Unable to lock ./ibdata1, error: 11

InnoDB: Check that you do not already haveanother mysqld process

InnoDB: using the same InnoDB data or logfiles.

…

InnoDB: Check that you do not already haveanother mysqld process

InnoDB: using the same InnoDB data or logfiles.

InnoDB: Unable to lock ./ibdata1, error: 11

InnoDB: Check that you do not already haveanother mysqld process

--这个提示的意思有多个mysqld 进程在运行。

解决方法：

（1）重新用：ps -ef|grep mysql 查询所有的进程，然后把所有的进程kill掉，

（2）重新对相关的目录赋权

[root@rac2 /]# chown mysql.mysql -R/var/lib/mysql/*

[root@rac2 /]# chmod 755 -R/var/lib/mysql/*

--再次启动成功：

[root@rac2 /]# service mysql start

Starting MySQL...... [ OK ]

[root@rac2 /]# ps -ef|grep mysql

root 27936 1 1 14:08 pts/1 00:00:00 /bin/sh /usr/bin/mysqld_safe--datadir=/var/lib/mysql --pid-file=/var/lib/mysql/rac2.pid

mysql 28193 27936 3 14:08 pts/1 00:00:00 /usr/sbin/mysqld --basedir=/usr--datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql--log-error=/var/lib/mysql/rac2.err --pid-file=/var/lib/mysql/rac2.pid--socket=/var/lib/mysql/mysql.sock --port=3306

root 28220 3596 0 14:08 pts/1 00:00:00 grep mysql

[root@rac2 /]# ll /var/lib/mysql/mysql.sock

srwxrwxrwx 1 mysql mysql 0 Nov 29 14:08/var/lib/mysql/mysql.sock

再次查看log：

[root@rac2 lib]# tail -20 /var/lib/mysql/rac2.err

111129 14:51:53 [Note] Event Scheduler:Purging the queue. 0 events

111129 14:51:53 InnoDB: Starting shutdown...

111129 14:51:54 InnoDB: Shutdown completed; log sequencenumber 1605950

111129 14:51:54 [Note] /usr/sbin/mysqld:Shutdown complete

111129 14:51:54 mysqld_safe mysqld from pidfile /var/lib/mysql/rac2.pid ended

111129 14:53:34 mysqld_safe Starting mysqlddaemon with databases from /var/lib/mysql

111129 14:53:34 [Note] Plugin 'FEDERATED'is disabled.

111129 14:53:34 InnoDB: The InnoDB memoryheap is disabled

111129 14:53:34 InnoDB: Mutexes andrw_locks use GCC atomic builtins

111129 14:53:34 InnoDB: Compressed tablesuse zlib 1.2.3

111129 14:53:34 InnoDB: Using Linux nativeAIO

111129 14:53:34 InnoDB: Initializing bufferpool, size = 128.0M

111129 14:53:34 InnoDB: Completed initializationof buffer pool

111129 14:53:35 InnoDB: highest supportedfile format is Barracuda.

111129 14:53:35 InnoDB:1.1.8 started; log sequence number 1605950

111129 14:53:35 [Warning] Neither--relay-log nor --relay-log-index were used; so replication may break when thisMySQL server acts as a slave and has his hostname changed!! Please use'--relay-log=rac2-relay-bin' to avoid this problem.

111129 14:53:35 [Note] Event Scheduler:Loaded 0 events

111129 14:53:35 [Note]/usr/sbin/mysqld: ready for connections.

Version: '5.5.15-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL)

[root@rac2 lib]#

说明：

因为之前没有保留的相关信息，修改之后，虽重复模拟多次，都不能还原当时的故障，所有缺少足够多的一手资料来证明这个问题。但是我这里的2种方法都可以尝试一下：

MySQL server PID file could not befound!

--可能是相关目录的权限问题导致

Check that you do not already have anothermysqld process

--重复进程导致，可以先ps，在kill掉相关进程在重试。

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