Upgrading a BlackBerry Enterprise Server and a BlackBerry Configuration Database that are configured for replication
If you configured previous BlackBerry® Enterprise Server versions for disaster recovery as documented in BlackBerry Enterprise Server Disaster Recovery Guide, you installed a BlackBerry Enterprise Server and a replicated BlackBerry Enterprise Server. When you upgrade the BlackBerry Enterprise Server instances that are configured for disaster recovery, you can upgrade the BlackBerry Enterprise Server instances and configure high availability instead. When you configure high availability, you can also configure automatic failover, which permits a standby BlackBerry Enterprise Server to take over from a primary BlackBerry Enterprise Server without intervention from an administrator.
If you configured database replication for the BlackBerry Configuration Database, you can continue to use database replication after the upgrade process completes. However, during the upgrade process, you must turn off database replication. After the upgrade process completes, you must reconfigure the replicated BlackBerry Configuration Database manually.
As an alternative to database replication, you can configure database mirroring after the upgrade process completes. If you configure database mirroring and if you configure the BlackBerry Enterprise Server instances to support database mirroring, when the principal BlackBerry Configuration Database stops responding, the BlackBerry Enterprise Server can automatically switch to the mirror BlackBerry Configuration Database without intervention from an administrator.