Continuous availability (CA) for vRealize Operations Manager prevents loss of data during a node failure and ensures availability of vRealize Operations during a physical location failure.

Note: The master node is now referred to as the primary node. The master replica node is now referred to as the primary replica node.
CA segregates the vRealize Operations Manager cluster into two fault domains, stretching across vSphere clusters, and protects the analytics cluster against the loss of an entire fault domain. The two fault domains are Fault Domain 1 and Fault Domain 2. By default, the primary node and the replica node are assigned to Fault Domain 1 and Fault Domain 2. If Fault Domain 1 fails, the functionality is not disrupted as the other pair node ensures that the incident results in no data loss.

The Witness Node is the third network domain that exists independently and identifies network partitioning across the two fault domains. If network connectivity between the two fault domains is lost, the cluster goes into a split-brain situation, which is detected by the Witness Node. Immediately, one of the fault domains goes offline to avoid data inconsistency problems.

Note: A minimum of three pairs of nodes are required to enable CA. You can add a maximum of 16 data nodes, including the primary and replica nodes.