It is sometimes necessary to run two instances of mysql, like in my case. I need a mysql database in addition to the one Zimbra uses. One solution to this problem is to run the mysql database on a non default socket. This can be done by changing the following line in my.cnf
[client] ... socket = /var/run/mysqld/mysqld2.sock
Restart the mysql daemon afterwards to activate the change.
In PHP it’s possible to avoid programming the nondefault socket info whenever we use mysql
[MySQL] ... mysql.default_socket = /var/run/mysqld/mysqld2.sock
If you don’t have access to php.ini you have to program this in your PHP code
$dbcnx = @mysql_connect('localhost:/var/run/mysqld/mysqld2.sock',$username, $password);