By default, IIS will shut down your application pool when it has been idle for more than 20 minutes. This is annoying when your website is only visited sporadically; visitors might not have the patience to wait for your application pool to spin up again. When you're running your own machine, you can higher or disable the idle-timeout, but when you're running on a cloud service like AppHarbor you can't. One solution is to frequently make a request yourself to keep the application pool alive. You can use a third party service (like Pingdom or StillAlive), but chances are you don't want to take an extra dependency for something that trivial. AppHarbor contains the required infrastructure to do this yourself: background workers and scheduling.