在安裝好了MySQL之后，使用了新的配置文件后，MySQL服務器可以成功啟動，但在登陸的時候出現(xiàn)了ERROR 2002 (HY000): Can't connect to local MySQL server through socket，即無法通過socket連接到mysql服務器，同時提供了socket文件的位置。下面是這個問題的描述與解決辦法。

1、故障現(xiàn)象

復制代碼代碼如下:

[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)

#故障環(huán)境

[root@SZDB mysqldata]# more /etc/issue

CentOS release 5.9 (Final)

Kernel \r on an \m

2、故障分析

復制代碼代碼如下:

#查看mysql實例的狀態(tài)

[root@SZDB mysqldata]# netstat -ntlp  | grep 3306

tcp        0      0 :::3306                     :::*                        LISTEN      13001/mysqld

#查看my.cnf關(guān)于socket的配置

[root@SZDB mysqldata]# more /etc/my.cnf |grep sock

socket = /tmp/mysql.sock

#由上可知my.cnf中定義的為/tmp目錄下，而錯誤提示為/data/mysqldata/目錄下

#也就是說mysqld已經(jīng)聲稱了正確的sock文件，但客戶端連接還是從初始目錄去找sock文件

#下面查看后臺日志，有個ERROR，是關(guān)于滿查詢?nèi)罩镜模怯捎谀夸洸淮嬖诙a(chǎn)生的錯誤，與當前故障無關(guān)

[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、解決故障

a、通過配置my.cnf mysql選項socket文件位置解決

復制代碼代碼如下:

#先停止mysql服務器

[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  #添加該行

#重啟mysql服務器

[root@SZDB mysqldata]# service mysqld start

Starting MySQL..[  OK  ]

#再次連接正常

[root@SZDB mysqldata]# mysql -uroot -p

Enter password: 

mysql> show variables like 'version';

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

| Variable_name | Value      |

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

| version       | 5.6.12-log |

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

b、為socket文件建立鏈接方式

復制代碼代碼如下:

[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，所以刪除之前的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 |

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