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

標籤：database   sql   dba   mysql   socket   

    在安裝好了MySQL之後，使用了新的設定檔後，MySQL伺服器可以成功啟動，但在登陸的時候出現了ERROR 2002 (HY000): Can‘t connect to local MySQL server through socket，即無法通過socket串連到mysql伺服器，同時提供了socket檔案的位置。下面是這個問題的描述與解決辦法。

 

1、故障現象
[[email protected] 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)

#故障環境
[[email protected] mysqldata]# more /etc/issue
CentOS release 5.9 (Final)
Kernel \r on an \m

 

2、故障分析
#查看mysql執行個體的狀態
[[email protected] mysqldata]# netstat -ntlp  | grep 3306
tcp        0      0 :::3306                     :::*                        LISTEN      13001/mysqld

#查看my.cnf關於socket的配置
[[email protected] 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已經聲稱了正確的sock檔案，但用戶端串連還是從初始目錄去找sock檔案
#下面查看後台日誌，有個ERROR，是關於滿查詢日誌的，是由於目錄不存在而產生的錯誤，與當前故障無關
[[email protected] 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、解決故障
a、通過配置my.cnf mysql選項socket檔案位置解決
#先停止mysql伺服器
[[email protected] mysqldata]# service mysqld stop
Shutting down MySQL.[  OK  ]

#修改my.cnf，如下
[[email protected] mysqldata]# vi /etc/my.cnf
[mysql]
no-auto-rehash
socket = /tmp/mysql.sock  #添加該行

#重啟mysql伺服器
[[email protected] mysqldata]# service mysqld start
Starting MySQL..[  OK  ]

#再次串連正常
[[email protected] mysqldata]# mysql -uroot -p
Enter password:
mysql> show variables like ‘version‘;
+---------------+------------+
| Variable_name | Value      |
+---------------+------------+
| version       | 5.6.12-log |
+---------------+------------+

 

b、為socket檔案建立連結方式
[[email protected] mysqldata]# ln -s /tmp/mysql.sock /data/mysqldata/mysql.sock
ln: creating symbolic link `/data/mysqldata/mysql.sock‘ to `/tmp/mysql.sock‘: File exists
[[email protected] mysqldata]# rm mysql.sock    #上面提示檔案存在，所以刪除之前的mysql.sock檔案
[[email protected] mysqldata]# ln -s /tmp/mysql.sock /data/mysqldata/mysql.sock
[[email protected] mysqldata]# ls -hltr mysql.sock
lrwxrwxrwx 1 root root 15 Oct 11 14:00 mysql.sock -> /tmp/mysql.sock
[[email protected] mysqldata]# mysql -uroot -p
Enter password:
mysql> show variables like ‘socket‘;
+---------------+-----------------+
| Variable_name | Value           |
+---------------+-----------------+
| socket        | /tmp/mysql.sock |
+---------------+-----------------+

 

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