If the primary unit becomes unavailable, another unit in the cluster is selected as the primary unit using the following rules:
- All cluster units are assigned a priority from 80 – 120. The default priority is 100. If the primary unit becomes unavailable, an available unit with the highest priority is selected as the new primary unit. For example, a unit with a priority of 110 is selected over a unit with a priority of 100.
- If multiple units have the same priority, the unit whose primary IP address has the greatest value is selected as the new primary unit. For example, 220.127.116.11 is selected over 18.104.22.168.
- If a new unit with a higher priority or a greater value IP address joins the cluster, the new unit does not replace (or preempt) the current primary unit.