http://www.jb51.net/article/56952.htm

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

复制代码 代码如下:

[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

复制代码

代码如下:

#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

3、解决故障

a、通过配置my.cnf mysql选项socket文件位置解决

复制代码

代码如下:

#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

复制代码

代码如下:

[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 |

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