Monitoring Large Clusters

Monitor large cluster traits by querying the following system tables:

• V_CATALOG.LARGE_CLUSTER_CONFIGURATION_STATUS—Shows the current spread hosts and the control designations in the catalog so you can see if they match.

• V_MONITOR.CRITICAL_HOSTS—Lists the hosts whose failure would cause the database to become unsafe and force a shutdown.

  The CRITICAL_HOSTS view is especially useful for large cluster arrangements. For non-large clusters, query the CRITICAL_NODES table.

• In an Eon Mode database, the CONTROL_SET_SIZE column of the V_CATALOG.SUBCLUSTERS system table shows the number of control nodes set for each subcluster.

You might also want to query the following system tables:

• V_CATALOG.FAULT_GROUPS—Shows fault groups and their hierarchy in the cluster.

• V_CATALOG.CLUSTER_LAYOUT—Shows the relative position of the actual arrangement of the nodes participating in the database cluster and the fault groups that affect them.