One Listener for the Entire Cluster

One listener serves all Real Application Clusters instances on all nodes. The listener listens on an address that is represented by a LogicalHostname resource. This configuration ensures that the address is plumbed very quickly on another node after a node fails.

You can use this configuration if you configure Real Application Clusters instances to use a multithreaded server (MTS). In such a configuration, the REMOTE_LISTENERS parameter in the init.ora file specifies that each dispatcher registers with the listener on a logical IP address.

All clients connect through the one listener. The listener redirects each client connection to the least busy dispatcher. The least busy dispatcher might be on a different node from the listener.

If the listener fails, the listener's fault monitor restarts the listener. If the node where the listener is running fails, the listener is restarted on a different node. In both situations the dispatchers reregister after the listener is restarted.

If you are using one listener for the entire cluster, configure the following resources in the same resource group:

• The listener resource

• The LogicalHostname resource

For more information, see LogicalHostname Resources for Oracle Listener Resources.