How Recovery Appliance Replicates Backups: Basic Process

Assume that a protected database backs up to a Recovery Appliance using the incremental-forever policy. When an protected database sends a backup to a Recovery Appliance configured for replication, the following basic steps occur:

1. The upstream Recovery Appliance ingests the backup, checking the protection policy to determine whether it is associated with a replication server configuration.

2. If a replication server configuration exists for the protection policy, then the upstream Recovery Appliance replicates the backup. The replication process includes:

   • Creating metadata records to track the replicated records

     Note:

     When real-time redo transport is enabled, incoming redo changes are not replicated in real time by Recovery Appliance. When an archived redo log backup is created, the Recovery Appliance automatically replicates this backup along with the data file backups.

   • Transferring the data blocks over the network to each specified downstream Recovery Appliance

3. The downstream Recovery Appliance ingests the backup, creating a virtual backup.

   Note:

   The ingest phase on the downstream is the same as the ingest phase described in Step 1. Thus, if the downstream Recovery Appliance is also configured to replicate the backup, then it assumes the role of an upstream Recovery Appliance, and then replicates the backup to the Recovery Appliances that are directly downstream, and so on.

4. Shortly afterward, the upstream Recovery Appliance sends a reconcile request to the downstream Recovery Appliance, which in turn sends metadata about the backup to the upstream Recovery Appliance.

   In Recovery Appliance replication, reconciling is the process by which a Recovery Appliance receives metadata from the Recovery Appliances that are immediately downstream.

Thus, after the backup is replicated, both the upstream and downstream recovery catalog have a record of the protected database backup.