Active/Passive Deployment Model
The Active/Passive model is for U-Series Appliances only. It fails over to a mirrored U-Series Appliance in the event the primary U-Series Appliance is not available. Failover is automatic. This method involves two U-Series Appliances configured as a pair.
U-Series Appliance pairs have to be identical i.e., U-Series 20 > U-Series 20, U-Series 50 > U-Series 50, U-Series v20 > U-Series v20.
The database is mirrored via port 5022 (configurable). A heartbeat is sent from the primary U-Series Appliance to the secondary U-Series Appliance every 130 seconds (non-configurable). If a heartbeat has not been detected for 14 minutes (default, range: 5 - 10,000 minutes), the secondary U-Series Appliance promotes itself to a primary.
The secondary U-Series Appliance promotes itself to primary and starts servicing requests.
When the previous primary U-Series Appliance in Site A starts up, it looks for a replica partner. If the replica is found, the Site A U-Series Appliance starts in secondary mode, and the database is replicated from Site B.
While the recovery takes place, the new primary U-Series Appliance in Site B is taken offline as the database is replicated.
At this point, the U-Series Appliances remain in their current roles; Site B continues to be the primary U-Series Appliance, and Site A becomes the new secondary.
If you need to revert the roles, wait for replication to complete and then follow these steps:
- Disable HA on Site B (breaks pair).
- Enable HA on Site A (re-establishes pair with new primary being Site A).