Web servers, like any application, can crash unexpectedly. When developing an application, these failures are easily fixed with a quick restart. However, when running a production web application, you will need the server to quickly and easily restart itself so that your application stays functioning for as many users as possible. One common solution to this problem is using a process manager to watch your application's process and restart it if it stops.

There are many different process managers available for Express, but we will use Forever, a simple but very popular process manager.