Performing Failover v6.2

Failover is the replacement of the publication database by the subscription database should a failure occur on the publication database or its host. Failover is considered an irreversible action so the subscription database permanently takes over the role of the publication database.

Generally, the same steps must be followed to perform a failover as was discussed for a controlled switchover in section Performing Controlled Switchover. However, the following points must also be taken into consideration:

  • If the control schema objects on the publication database (that is, schemas _edb_replicator_pub, _edb_replicator_sub, _edb_scheduler, and their objects) cannot be salvaged or restored from a backup, then performing a failover may only be possible with the assistance of EnterpriseDB Technical Support Services.
  • Pending updates not yet applied to the subscription may have been lost. The chances of this are greater if the interval between synchronizations is long.

If you determine that a failover is possible, follow the steps for a controlled switchover.