在安裝好了MySQL之后，使用了新的配置文件后，MySQL服務(wù)器可以成功啟動(dòng)，但在登陸的時(shí)候出現(xiàn)了ERROR 2002 (HY000): Cant connect to local MySQL server through socket，即無(wú)法通過(guò)socket連接到mysql服務(wù)器，同時(shí)提供了socket文件的位置。下面是這個(gè)問(wèn)題的描述與解決辦法。

故障情況：

    [root@landui mysqldata]# mysql -uroot 
    Warning: Using a password on the command line interface can be insecure.
    ERROR 2002 (HY000): Cant connect to local MySQL server through socket /data/mysqldata/mysql.sock (111)
    #故障環(huán)境
    [root@landui mysqldata]# more /etc/issue
    CentOS release 5.9 (Final)
    Kernel on an m
故障分析：

    #查看mysql實(shí)例的狀態(tài)
    [root@landui mysqldata]# netstat -ntlp  | grep 3306
    tcp        0      0 :::3306                     :::*                        LISTEN      13001/mysqld
    #查看my.cnf關(guān)于socket的配置
    [root@landui 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(cuò)誤提示為/data/mysqldata/目錄下
    #也就是說(shuō)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(tái)日志，有個(gè)ERROR，是關(guān)于滿查詢?nèi)罩镜?，是由于目錄不存在而產(chǎn)生的錯(cuò)誤，與當(dāng)前故障無(wú)關(guān)
    [root@landui mysqldata]# more landui.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
解決方法：

1、通過(guò)配置my.cnf mysql選項(xiàng)socket文件位置解決

    #先停止mysql服務(wù)器
    [root@landui mysqldata]# service mysqld stop
    Shutting down MySQL.[  OK  ]
    #修改my.cnf，如下
    [root@landui mysqldata]# vi /etc/my.cnf
    [mysql]
    no-auto-rehash
    socket = /tmp/mysql.sock  #添加該行
    #重啟mysql服務(wù)器
    [root@landui mysqldata]# service mysqld start
    Starting MySQL..[  OK  ]
    #再次連接正常
    [root@landui mysqldata]# mysql -uroot -p
    Enter password: 
    mysql> show variables like version;
    +---------------+------------+
    | Variable_name | Value      |
    +---------------+------------+
    | version       | 5.6.12-log |
    +---------------+------------+

2、為socket文件建立鏈接方式

    [root@landui 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@landui mysqldata]# rm mysql.sock    #上面提示文件存在，所以刪除之前的mysql.sock文件
    [root@landui mysqldata]# ln -s /tmp/mysql.sock /data/mysqldata/mysql.sock
    [root@landui mysqldata]# ls -hltr mysql.sock
    lrwxrwxrwx 1 root root 15 Oct 11 14:00 mysql.sock -> /tmp/mysql.sock
    [root@landui mysqldata]# mysql -uroot -p
    Enter password: 
    mysql> show variables like socket;
    +---------------+-----------------+
    | Variable_name | Value           |
    +---------------+-----------------+
    | socket        | /tmp/mysql.sock |
    +---------------+-----------------+