How do you call a method every hour in Rails?

Question

I'm using Resque with Redis to process a background job. I'd like to call the method, Resque.enqueue(MyModel) just one time every hour to do a background task.

For example: Say I have a site that has a 10,000 users. I would like to call this method only 24 times per day; not 10,000 * 24. The example method is below:

Resque.enqueue(MyModel)

Thank you for your help in advance. I should also mention I prefer to stick with Resque, and not move to Delayed Job. Thank you.

Answer 1

You should use a cron job for this kind of task.

I suggest you use the Whenever gem.

See railscast here: http://railscasts.com/episodes/164-cron-in-ruby

Answer 2

Since you are already using Resque, I would recommend to use one of the many available Resque plugins: resque-scheduler. Plugs into the Resque UI very nicely as well. Simple setup as explained in the README. Also adds a lot of the missing DelayedJob stuff (delayed execution).

Why I switched from whenever to resque-scheduler:

• Stays in the app-folder and doesn't mess with your cron file.
• To stop all 'crons' just disable the Resque workers.
• Exceptions are logged to the Resque UI.
• Manual rescheduling via the Resque UI possible.
• In combination with resque-loner you prevent double-execution should a job take longer than the span between two executions.
• Still obeys to the priority-system of Resque.
• No additional boot-time (could take up to 60s if your app gets bigger) since it uses Resque's worker-pool.
• One less "tech" used.
• Simple switch: Configuration is done in a cron-like manner.