The cluster continuously monitors all its members. It blocks failed nodes from participating in the cluster, which prevents any exchange of corrupt data. The cluster also monitors applications, and it fails over or restarts the applications in case of failures.
Public Network Management, a subsystem of the Sun Cluster software, monitors the active interface. If the active adapter fails, Network Adapter Failover software is called to fail over the interface to one of the backup adapters.
The Cluster Membership Monitor (CMM) is a distributed set of agents, with one set per cluster member or node. The agents exchange messages over the cluster interconnect to ensure full connectivity among all nodes. When the CMM detects a change in cluster membership because of a node failure, for example, the CMM reconfigures the cluster. If the CMM detects a critical problem with a node, the CMM contacts the cluster framework. The cluster framework then forcibly shuts down the node and removes it from the cluster membership.