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，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(wù)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
    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
    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(dāng)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
    代碼如下:
    #先停止mysql服務(wù)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(wù)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
    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 |
    +---------------+-----------------+