Manual:$wgDBserver/ru

Подробнее
Имя хоста базы данных или IP-адрес. Ищите в $LocalSettings.

If you are using MySQL on a non-standard port, you can use the -syntax, for example. Note that using a port number when you specify  as the host name will have no effect, as MySQL will connect through a socket instead. If the MySQL server is on the same server and you want to connect through a socket in a non-standard location, you can use the -location, for example.

См. также

 * - for multiple-server (master/slave) setups.