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.
-
Shutdown or disconnect the site-1.
-
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.
-
The site-2 starts notifying records of site-1 to the local application.
-
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.