GR Failover Notification Records of Peer Site

The CDL sends notification about records only to its local application. The notification is based on the system-id and Timer Expiry parameters of the records. In a GR setup, when a site is isolated for maintenance, the records of that site are not sent to its peer site.

With the remote-system-id parameter, CDL allows the peer site to process notifications of the isolated site. The remote-system-id of the peer site is configured with the site ID of the isolated site. The CDL processes records when the system-id of any record matches the remote-system-id. The notifications are sent based on the Timer Expiry, or for the records that have the notifyOnPurge enabled.

Note

The remote-system-id must be removed from the CDL configuration after the isolated site resumes its function.

The following procedure explains the configuration of remote-system-id with an example:

In the example below, the GR setup has 2 sites: site-1 and site-2. The site-1 is disconnected for an upgrade, and the remote-system-id of site-2 is configured with the site ID of site-1.

  1. Shutdown or disconnect the site-1.

  2. To configure the remote-system-id of site-2 with site ID of site-1, run the following command:

    
    cdl datastore session
        slot notification remote-system-id [ 1 ] 
    exit
    

    Note that the value [1] for remote-system-id in the above command is the site ID of site-1, which is isolated.

  3. The site-2 starts notifying records of site-1 to the local application.

  4. Before bringing up site-1, remove the site ID of site-1 from the remote-system-id list of site-2.

The remote-system-id is mutually exclusive with the instance-aware-notification-system-id. For more information, refer to the Geo Replication (GR) Failover Notification topic.