service registration

A feature by which instances and dispatchers automatically register information with a listener. Because this information is registered with the listener, the listener.ora file does not need to be configured with this static information.

During database startup, service registration provides the listener with information about:

- Service names for each running instance of the database

- Instance names of the database

- Service handlers (dispatchers and dedicated servers) available for each instance

  These enable the listener to direct a client request appropriately.

- Dispatcher, instance, and node load information

This load information enables the listener to determine which dispatcher can best handle a client connection request. If all dispatchers are blocked, the listener can spawn a dedicated server for the connection.