Manual:$wgExternalServers

MySQL specific: $wgExternalServers
An array of external MySQL servers.
Introduced in version:	1.5.0 (r9118)
Removed in version:	still in use
Allowed values:	(see below)
Default value:	array()

Other settings: Alphabetical | By Function

Details

An array of external MySQL servers.

e.g.

$wgExternalServers = array( 'cluster1' => array( 'srv28', 'srv29', 'srv30' ) );