Rails keeps being rebooted in production Passenger

Question

I'm running an application that kicks off a Rufus Scheduler process in an initializer. The application is running with Passenger in production and I've noticed a couple weird behaviors:

First, in order to restart the server and make sure the initializer gets run, you have to both touch tmp/restart.txt and load the app in a browser. At that point, the initializer fires. The horrible thing is that if you only do the touch, the processes scheduled by Rufus get reset and aren't rescheduled until you load the app in a browser.

This alone I can deal with. But this leads to the second problem: I'll notice that the scheduled process hasn't run, so I load a page and suddenly the log file is telling me that it's running the initializers as if I'd rebooted. So, at some point, Passenger is randomly rebooting as if I'd touched tmp/restart.txt and wiping out my scheduled processes.

I have an incredibly poor understanding of Passenger and Rails's integration, so I don't know whether this occasional rebooting is aberrant or all part of the architecture. Can anyone offer any wisdom on this situation?

Answer 1

What you describe is the way Passenger works. It spawns new instances of the application when traffic warrants them, and shuts them down after periods of inactivity to free resources.

You should read the Passenger documentation, particularly the Resource Control and Optimization section. There are settings which can prevent the application from being shut down by Passenger, if that is what you want.

Using the PassengerPoolIdleTime setting, you could keep at least one process running, but you'll almost certainly want Passenger to start up other instances of the app as necessary. This thread on the Rufus Scheduler Google Group mentions using lock files to prevent more than one process from starting the scheduler, that may be useful to you.