9.6 Understanding Listener Redirects

The listener redirect feature allows a client to connect to a pluggable database (PDB) using an unchanged connect descriptor even after the PDB is migrated to a new location in the Oracle Public Cloud.

The Listener Registration (LREG) process registers a new handler with the local listener for the PDB or the service which is in the process of migration. This handler contains the new listener address of the database where the PDB or the service is migrated. The new listener address can be that of a Single Client Access Name (SCAN) listener in case of an Oracle RAC database or a local listener in case of a single-instance database. The listener then redirects the client to the new address.

If a local listener redirects to a SCAN listener in an Oracle RAC configuration, then this listener may need to further redirect the client connection request to another cluster node. Such multiple redirects are not supported by Oracle Net listeners by default. To allow the SCAN listener to forward the already redirected client connection request, add the ALLOW_MULTIPLE_REDIRECTS_listener_name parameter to its listener.ora file. Set the parameter to TRUE. Do not set this parameter for node listeners because it may allow infinite redirection loops in certain network configurations.