When secondary replication is being performed, as shown in the following figure, both databases are up and running and all secondary transactions are being replicated to the primary database.

Figure 1. Secondary replication continues (before controlled transition)


At this point, the secondary is considered the production database and the primary is considered the replica.

While secondary replication is occurring and the Replication server and agent are actively performing Replication, you must determine when the best time is to fail back production processing to the primary computer.

The following figure illustrates the scheduling of database downtime.

Figure 2. Scheduling downtime to perform failback


When you begin failback processing, it is critical that no users be connected to either the primary or the secondary database. Both databases must be shut down to transition them.

It is recommended that the transition configuration for both the primary and the secondary databases be checked and modified if needed at this time.

CAUTION: Do not restart the databases after transition, so that you are able to perform special actions in the event of a transition failure. Once you verify that no users are connected to either database, you can start the failback process.