If your organization's environment includes Microsoft® SQL Server® 2005 SP2 or later, you can configure database mirroring. Database mirroring requires a principal database, mirror database, and, optionally, a witness. Although the BlackBerry® Enterprise Server can contact the mirror database, it opens active connections to the principal database only. If the principal database stops responding, the BlackBerry Enterprise Server opens an active connection to the mirror database automatically. Database mirroring provides fault tolerance for the BlackBerry® Enterprise Solution.
If your organization's environment includes a version of Microsoft SQL Server that is earlier than version 2005 SP2, you can configure transactional replication of the BlackBerry Configuration Database and create a replicated BlackBerry Configuration Database. If the BlackBerry Configuration Database stops responding, you must fail over the BlackBerry Enterprise Server to the replicated BlackBerry Configuration Database manually.
For more information about database mirroring, visit www.microsoft.com.