Cluster Membership

The main function of the CMM is to establish cluster-wide agreement on the set of nodes that participates in the cluster at any given time. This constraint is called the cluster membership.

To determine cluster membership, and ultimately, ensure data integrity, the CMM:

• Accounts for a change in cluster membership, such as a node joining or leaving the cluster

• Ensures that a "bad" node leaves the cluster

• Ensures that a "bad" node stays out of the cluster until it is repaired

• Prevents the cluster from partitioning itself into subsets of nodes

See "Quorum and Quorum Devices" for more information on how the cluster protects itself from partitioning into multiple separate clusters.