Episodic replication job failover and failback
Typically, the source cluster drives an episodic replication session. However, in some situations, it may be useful for the destination cluster to drive the episodic replication session. Access Appliance supports a failover and a failback feature for episodic replication jobs. This feature enables control of episodic replication jobs to be temporarily relocated from the source cluster to the destination (target) cluster.
Job failover and failback is useful for:
Planned failover
In cases where the source cluster is taken down for routine maintenance or for moving applications to another cluster, a planned failover procedure is available for moving episodic replication jobs from the source cluster to the destination cluster.
Unplanned failover or Disaster recovery
In cases where the source cluster fails unexpectedly, an unplanned failover procedure is available for moving episodic replication jobs to the destination cluster.
Note:
In the event of a planned or unplanned failover from the source cluster to the destination cluster, there should be at least one successful sync attempt. The successful sync ensures that a consistent point in time image is present on the destination cluster that can be used for the failover.
With job failover and failback, you use the Replication> episodic job failover command to move control from the source cluster to the destination cluster. You use the Replication> episodic job failback to restore control to the source cluster. The link_name is the link of one of the destination clusters. The link_name argument can be empty when the source cluster is not available, in which case the job failover can be run from one of the destination clusters.
Essentially, job failover takes job and episodic replication unit definitions from the episodic replication database on the source cluster and copies them to the episodic replication database on the destination cluster.
Warning:
Job failover assumes that all episodic replication job names and episodic replication unit names are unique across all Access Appliance clusters on your network. Before you use the episodic replication failover feature, make sure that these names are unique.
After a job failover or failback, you must manually start or enable the episodic replication job to start preconfigured schedules. Link throttle information should be reconfigured after the job failover or failback.
Job failover does not automatically move the NFS or the CIFS share information that is associated with job failover episodic replication units from the source cluster to the destination cluster. Share information has to be done manually.
Table: Job failover and failback commands
Command | Definition |
|---|---|
episodic job failover | Transfer control of an episodic replication job from the source cluster to the destination cluster. |
episodic job failback | Return control of an episodic replication job from the destination cluster to the source cluster. |