You must perform this operation in the old API Gateway instance. For a cluster setup, you must do this on each node as Quiesce mode is performed at instance level.

At this time, the runtime traffic is flowing to both old and new API Gateway instances. You must stop the traffic to old instances and allow the traffic to be sent only to the new instances. But while stopping the old instances, there may be ongoing requests in the old instances that are in progress and cannot be lost. Moreover, all the in-memory data like performance metrics, license metrics, and subscription quota must be stored in the Elasticsearch or API Data Store before runtime data is migrated. This can be achieved by putting the old instances into quiesce mode with status as all.

For more information on the process of enabling and disabling quiesce mode, see API Gateway Quiesce Mode.

If the quiesce mode for all request invocation fails with an error or the status is returned with a failure, you must stop the execution of the next steps. Disable the quiesce mode for design time in all the nodes and bring them back to normal state. If the instances have already entered the quiesce mode, restart all the instances and update the load balancer to route the traffic only to it to go back to the original state before migration. If the error persists, contact Software AG support team for help with all the relevant logs for further analysis.