Hi there,
Private services do have TCP health checks (The same as web services if you don’t use a health check path. Adding the health check path to web services changes the check to use HTTP). If we cannot make a TCP connection to your service, we will mark it as unhealthy and restart the service.
For background workers, because they usually don’t listen on port, we don’t perform health checks on them. If you were to add a server of some sort to your worker and deploy it as a private service, then the health checks would run for these services.
Regards,
Keith
Render Support, UTC+10 