It was becoming a problem though, that after an hour of disuse the apps would go into idle mode. When an app is idling, the time to start it up again ranges from 8 - 15 seconds, at which point many users would just give up and click elsewhere.
I fixed this by installing a Heroku add-on called Scheduler. This add-on makes it possible to carry out tasks periodically. I then wrote a rake command that sent a GET request to all of my apps, keeping them from idling.
- Difference between web and worker dynos
- Building custom rake tasks
- Heroku add-ons