Sun Cluster Concepts Guide for Solaris OS

Cluster Membership Monitor

To ensure that data is kept safe from corruption, all nodes must reach a consistent agreement on the cluster membership. When necessary, the CMM coordinates a cluster reconfiguration of cluster services (applications) in response to a failure.

The CMM receives information about connectivity to other nodes from the cluster transport layer. The CMM uses the cluster interconnect to exchange state information during a reconfiguration.

After detecting a change in cluster membership, the CMM performs a synchronized configuration of the cluster. In a synchronized configuration, cluster resources might be redistributed, based on the new membership of the cluster.

Unlike previous Sun Cluster software releases, CMM runs entirely in the kernel.

See About Failure Fencing for more information about how the cluster protects itself from partitioning into multiple separate clusters.