Edd Mann has written up a tutorial for the MyBuilder.com Tech blog about managing background processes in a Symfony application with the help of Supervisor.

When a web application reaches a sufficiently large size, it can become infeasible to perform all actions required within a single web request/response life-cycle. You may find yourself wishing to for example - batch up and send queued emails at particular intervals, or process payments asynchronous to the point in-time the user made the initial request. In this post I would like to discuss our changing use of background processes (both time-dependent and continuous) due to increasing throughput demands.

He starts out with the first approach most applications take when needing to run automated, asynchronous processes - cron. Using it and a custom bundle they created for it, Edd shows how to directly integrate the cron timing of commands into the class attributes. However, after a while the system grew and it needed something a bit more powerful than cron, something that could correctly handle long running processes. Ultimately they decided on Supervisor, a processes manager and control system that makes managing these processes simpler. He talks about the transition they made from cron over to Supervisor (safely) and how they integrated the signaling functionality Supervisor allows into their application.