ERROR 2002 (HY000): Can't connect to local MySQL server through socket

    在安装好了MySQL之后，使用了新的配置文件后，MySQL服务器可以成功启动，但在登陆的时候出现了ERROR 2002 (HY000): Can't connect to local MySQL server through socket，即无法通过socket连接到mysql服务器，同时提供了socket文件的位置。下面是这个问题的描述与解决办法。

1、故障现象 [root@SZDB mysqldata]# mysql -uroot -p123456 Warning: Using a password on the command line interface can be insecure. ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/data/mysqldata/mysql.sock' (111)

#故障环境 [root@SZDB mysqldata]# more /etc/issue CentOS release 5.9 (Final) Kernel \r on an \m

2、故障分析 #查看mysql实例的状态 [root@SZDB mysqldata]# netstat -ntlp  | grep 3306 tcp        0      0 :::3306                     :::*                        LISTEN      13001/mysqld

#查看my.cnf关于socket的配置 [root@SZDB mysqldata]# more /etc/my.cnf |grep sock socket = /tmp/mysql.sock

#由上可知my.cnf中定义的为/tmp目录下，而错误提示为/data/mysqldata/目录下 #也就是说mysqld已经声称了正确的sock文件，但客户端连接还是从初始目录去找sock文件 #下面查看后台日志，有个ERROR，是关于满查询日志的，是由于目录不存在而产生的错误，与当前故障无关 [root@SZDB mysqldata]# more SZDB.err              ............ 2014-10-11 13:17:21 13001 [Note] InnoDB: 5.6.12 started; log sequence number 1625997 /app/soft/mysql/bin/mysqld: File '/log/mysql_logs/slowquery.log' not found (Errcode: 2 - No such file or directory) 2014-10-11 13:17:21 13001 [ERROR] Could not use /log/mysql_logs/slowquery.log for logging (error 2). Turning logging off for the who le duration of the MySQL server process. To turn it on again: fix the cause, shutdown the MySQL server and restart it. 2014-10-11 13:17:21 13001 [Note] Server hostname (bind-address): '*'; port: 3306 2014-10-11 13:17:21 13001 [Note] IPv6 is available. 2014-10-11 13:17:21 13001 [Note]   - '::' resolves to '::'; 2014-10-11 13:17:21 13001 [Note] Server socket created on IP: '::'. 2014-10-11 13:17:21 13001 [Note] Event Scheduler: Loaded 0 events 2014-10-11 13:17:21 13001 [Note] /app/soft/mysql/bin/mysqld: ready for connections. Version: '5.6.12-log'  socket: '/tmp/mysql.sock'  port: 3306  Source distribution #Author ：Leshami #Blog   : http://blog.csdn.net/leshami

3、解决故障 a、通过配置my.cnf mysql选项socket文件位置解决 #先停止mysql服务器 [root@SZDB mysqldata]# service mysqld stop Shutting down MySQL.[  OK  ]

#修改my.cnf，如下 [root@SZDB mysqldata]# vi /etc/my.cnf [mysql] no-auto-rehash socket = /tmp/mysql.sock  #添加该行

#重启mysql服务器 [root@SZDB mysqldata]# service mysqld start Starting MySQL..[  OK  ]

#再次连接正常 [root@SZDB mysqldata]# mysql -uroot -p Enter password: mysql> show variables like 'version'; +---------------+------------+ | Variable_name | Value      | +---------------+------------+ | version       | 5.6.12-log | +---------------+------------+

b、为socket文件建立链接方式 [root@SZDB mysqldata]# ln -s /tmp/mysql.sock /data/mysqldata/mysql.sock ln: creating symbolic link `/data/mysqldata/mysql.sock' to `/tmp/mysql.sock': File exists [root@SZDB mysqldata]# rm mysql.sock    #上面提示文件存在，所以删除之前的mysql.sock文件 [root@SZDB mysqldata]# ln -s /tmp/mysql.sock /data/mysqldata/mysql.sock [root@SZDB mysqldata]# ls -hltr mysql.sock lrwxrwxrwx 1 root root 15 Oct 11 14:00 mysql.sock -> /tmp/mysql.sock [root@SZDB mysqldata]# mysql -uroot -p Enter password: mysql> show variables like 'socket'; +---------------+-----------------+ | Variable_name | Value           | +---------------+-----------------+ | socket        | /tmp/mysql.sock | +---------------+-----------------+