|
|
After a failover, if cluster members in the primary cluster become available again, the mirrored cluster support attempts to fail back the requests to the primary cluster. This fail back is automatic. However, for the failback to work, the primary cluster must be defined as a backup for the backup cluster. In other words, both primary and backup clusters must have a backup configured, and each cluster's backup must point to the opposite cluster.
Note that the mirrored cluster failover support is not a cell level failover or Node Agent level failover. For the most part, the mirrored cluster support depends on a running Deployment Manager and is limited to cluster failover only. For example, if the primary cluster's entire cell stops processing, a new client's requests to the primary cluster will fail and is not sent to the backup cluster. This is because information regarding the backup cluster cannot be retrieved from the primary cluster's cell because the primary cluster's cell is not processing. On the other hand, if the primary cluster's cell Deployment Manager, Node Agents, and appservers stop processing after the client has already been sending requests to the primary cluster, the client already knows about the backup cluster and is able to send the requests to the backup cluster.
