BTP Application error "The requested url could not be retrieved" after cell evacuation schedule

[Ravi777]

We have developed a Java-servlet based extension application for SAP SuccessFactors. Our deployment package includes both the Java application and the Approuter application, which customers deploy through the SAP BTP Cloud Foundry environment. We use Approuter for authentication, and once a request is successfully authenticated, it is forwarded to our Java application.

Normally, this application works fine. However, sometimes when a cell evacuation event is scheduled by Cloud Foundry, users receive the following error "The requested url could not be retrieved" when trying to access the application URL (via the approuter), even though both (main and approuter ) application are running in SAP BTP.

This issue is getting resolved automatically when Admin is restarting the main application from the BTP.