Heroku Delayed Job Autoscale

Simply put, this gem saves you money on Heroku by only running the workers when you need them.
When a new job is enqueued, this gem will fire up a new worker instance if none are running. When the job finishes, it'll shut it down.

Usage

Create a delayed job worker and include HerokuDelayedJobAutoscale::Autoscale:

class OnImageUpload
  include HerokuDelayedJobAutoscale::Autoscale

  def initialize(media)
    @media = media
  end

  def perform
    @media.create_thumb
  end
end

Done

Requirements

• Rush >= 0.6 - https://github.com/heroku/rush
• Heroku client >= 1 - https://github.com/heroku/heroku
• Delayed Job >= 2.1 - https://github.com/collectiveidea/delayed_job

I haven't tested lower versions, but it might work.

Caution

Autoscale uses two DJ hooks. #after and #enqueue, which it just passes onto two methods autoscale_after and autoscale_enqueue. If you need to use either of those hooks yourself in your DJ worker, make sure you pass on the job to the autoscale_methods manually.

Other

Work is based of pedro's autoscaling branch, but adapted for Delayed Job 2.1 and rails 3.