vRealize Automation components in a high availability cluster are groups of computers that support server applications that can be reliably utilized with a minimum downtime. They operate in HA mode to harness redundant computers in groups that provide a continued service when system components fail. Without high availability, if a server running a particular application crashes, the application will be unavailable until the crashed server is fixed:
All nodes are in active mode while handling the alike function on the same state. If there is a failure of one active node, then the other active node automatically handles the traffic. After the restoration of the failed node, it will enter the active mode routinely, where the load will be shared between the nodes. However, this depends on the session persistence settings used in the load balancer. CAFÉ, IaaS web server, DEM Worker, and proxy agents comes under this category...