- Introduced LBFactory -- an abstract class for configuring database load balancers and connecting to foreign DBs.
- Wrote two concrete implementations. LBFactory_Simple is for general installations. LBFactory_Multi will replace the runtime configuration used on Wikimedia and allow load-balanced connections to any DB.
- Ported Special:Userrights, CentralAuth and OAI audit to the LBFactory system.
- Added ForeignDBViaLBRepo, a file repository which uses LBFactory.
- Removed $wgLoadBalancer and $wgAlternateMaster
- Improved the query group concept to allow failover and lag control
- Improved getReaderIndex(), it will now try all servers before waiting, instead of waiting after each.
- Removed the $fail parameter to getConnection(), obsolete.
- Removed the useless force() function.
- Abstracted the replication position interface to allow for future non-MySQL support.
- Rearranged Database.php. Added a few debugging features.
- Removed ancient benet-specific hack from waitForSlave.php