Can't connect to local MySQL server through socket

[gsmforum]

Hi all !

I'm running a vbulletin forum for 10 years now.
Suddently, i started to get problems with MySQL, getting tons of emails giving this error:

mysql_pconnect() [<a href='function.mysql-pconnect'>function.mysql-pconnect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)


Anyway to fix this permanently ?
don't know what to do....

thanks

[lammert]

Did you check if the file /var/lib/mysql/mysql.sock exists? List the directory with the following command:

ls -ladF /var/lib/mysql/mysql*

The result should be this:

drwx------ 2 mysql mysql 4096 Apr 4 2010 mysql/
srwxrwxrwx 1 mysql mysql 0 Jan 7 00:16 mysql.sock=

Sometimes the mysql.sock doesn't exist because it has been erased accidentaly, and sometimes it is not a socket but a normal file. In that case the = is missing at the end of the file name with this specific directory listing command. If it is a file, deleting that file and restarting the MySQL server should do the trick.

You should also check if there has been a recent update of MySQL on your server which changed your my.cnf file. That file should at least contain the following lines:

[mysqld]
socket=/var/lib/mysql/mysql.sock