CDL Instance Awareness and Replication

In CDL, along with existing GR related parameters, GR instance awareness must be enabled using a feature flag on all sites. Also, the mapping of system-id to slice names should also be provided for this feature to work on all sites.

The CDL is also equipped with Geo Replication (GR) failover notifications, which can notify the timer expiry of session data and bulk notifications to the currently active site. The CDL uses Border Gateway Protocol (BGP) through App-Infra for the GR failover notifications.

The CDL subscribes to the key value on both the GR sites. The App-Infra sends notifications to the CDL when there is any change in these key values. A key value indicates the state of the CDL System ID or the GR instance. The GR instance is mapped to the CDL slices using the CDL system ID or the GR instance ID in the key.

The system ID is mandatory on both the sites. The GR instance ID in the NF configuration must match the CDL system ID.

CDL has instance-specific data slices. It also allows users to configure instance-specific slice information at the time of bringing up.

  • CDL notifies the data on expiry or upon bulk notification request from the active slices.

  • CDL determines the active instance based on the notification from app-infra memory-cache.

  • CDL slice is a partition within a CDL instance to store a different kind of data. In this case, NF stores a different instance of data.

Note

CDL slice name should match with the slice-name configured in GR.