'Always on' setting keeps the app loaded even when there's no traffic. When 'Always On' is not turned on (default), the app is unloaded after 20 minutes without any incoming requests. The unloaded app can cause high latency for new requests because of its warm-up time. When 'Always On' is turned on, the front-end load balancer sends a GET request to the application root every five minutes. The continuous ping prevents the app from being unloaded.