Manual:$wgAlternateMaster/en

From Linux Web Expert

<translate> LoadBalancer settings</translate>: $wgAlternateMaster
A map of database name to connection index.
<translate> Introduced in version:</translate>1.10.0
<translate> Removed in version:</translate>1.13.0
<translate> Allowed values:</translate>(array)
<translate> Default value:</translate>array()

Details

A map of database name (key) to connection index (value), describing the master database server for each database. The connection index is an index into the $wgDBservers array. If a database is not listed here, the default load balancing settings will be used.

To use this feature in 1.13 and above, you have to customize $wgLBFactoryConf and use LBFactory_Multi as class.