Oracle Data Guard Broker and Static Service Registration (Doc ID 1387859.1)

Last updated on JANUARY 08, 2024

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.2 to 12.1.0.2 [Release 12.1]
Oracle Database - Enterprise Edition - Version 12.2.0.1 to 12.2.0.1 [Release 12.2]
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Information in this document applies to any platform.

Goal

Note: Static entries are only used by the Broker itself via the Broker defined StaticConnectIdentifier property. They are NEVER to be used for any other purpose by the user. This includes using it for the normal DGConnectIdentifier, RMAN connections or anything else. Also note that you must never define a static entry for the Broker 'DGB' service. That service is for the Broker exclusive use. Also note that using the "_DGMGRL" or "_DGB" in your TNSNAMES definition is expressly forbidden.

Note: Static "_DGMGRL" entries are no longer needed as of Oracle Database 12.1.0.2 in Oracle Data Guard Broker configurations that are managed by Oracle Restart, RAC On Node or RAC as the Broker will use the clusterware to restart an instance.

As per the Oracle Data Guard Broker manuals since Oracle Database 10g Release 2, (see the Oracle Data Guard Broker 11g Release 2 (11.2) section 2.2 for the current documentation), all Data Guard Broker configurations must have a specific static listener entry configured in the local listener of each instance in the Data Guard configuration for the Primary database and all standby databases. A static entry is needed for the Broker to be able to connect remotely to a database that has been shut down by the Broker during certain operations. They are required for the Broker to complete the following operations:

Switchover from the Primary database to a Physical Standby database
Reinstatement of failed Primary database after a manual or automatic failover has occurred.
Conversion of a Snapshot Standby database back to a Physical Standby database

To access a database that has been shutdown in one of the above situations, the Broker uses a default name for the static entry using the information from the LOCAL_LISTENER parameter of the instance and the keyword "_DGMGRL" and stores that information in the broker StaticConnectIdentifier property associated with each instance of the database. As a best practice, users should not change the default values assigned to the Broker StaticConnectIdentifier property or to the database LOCAL_LISTENER initialization parameter as the value of the StaticConnectIdentifier property will be automatically updated by the Broker whenever the instance specified by the SidName property is started on a different host.

Note: If the StaticConnectIdentifier property or the LOCAL_LISTENER parameter will be changed by the user then please refer to the section at the end of this note titled "StaticConnectIdentifier and LOCAL_LISTENER" for additional user requirements.

Because each static service registration is associated with a specific host, the registration is always made with the local (host-specific) listener.

From 11.2 on, never register the entries with the SCAN listener as it is not associated with a specific host.

As a general rule, a static service registration is required for each possible instance on each possible host. The examples in this note will help to ensure that users correctly configure any needed static services.

Since a Data Guard configuration can comprise of multiple types of Oracle databases, care must be taken to configure the static entries for the specific type of database. There are five possible types of database that must be taken into account.