Try the following steps to troubleshoot.
- Ensure ContentServiceCapability registered with the discovery (DXA model extension works without configuration it's mandatory to register the ContentServiceCapability before content service restart, either install the service with auto-register or run the discovery registration and then restart the service, otherwise add-on service doesn't know about the service role)
- Stop the add-on service and restart the session content service to leave it 2 to 3mins, I would expect session content service would go down and also expect to see this below error message in your cd_core.logs
2020-05-25 17:00:10,554 ERROR [main] AddonClientFacade - Add-on
service specified by URL: 'http://localhost:83/addon' is not up and
running but it's mandatory for service to work properly
java.lang.RuntimeException: Retry limit exceeded. at
Caused by: org.springframework.web.client.ResourceAccessException: I/O
error on GET request for "http://localhost:83/addon/api/v1/health":
Connection refused: connect; nested
- Also, try to enable DEBUG logs to see what it's going on
- Ensure add-on service URL either passed in the service start-up parameters or the following below environment variables created as per your environment
# Create the system environment variables
- In the application.properties ensure the following properties configured
# add-on heartbeat interval. determines how often we should report live status of a service to add-on service.
# default value is every 60000 millis = 1 minute.
I hope it helps