Quick Dirty Heroku AutoScaling script that may save you money. Works with Delayed Job.

heroku_autoscaler.rb

# Inspired by http://verboselogging.com/2010/07/30/auto-scale-your-resque-workers-on-heroku

module HerokuAutoscale
  module Scaler
    class << self
      @@heroku = Heroku::Client.new(ENV['HEROKU_USER'], ENV['HEROKU_PASS'])

      def workers
        @@heroku.info(ENV['HEROKU_APP'])[:workers].to_i
      end

      def workers=(qty)
        @@heroku.set_workers(ENV['HEROKU_APP'], qty)
      end

      def job_count
        Delayed::Job.count
      end
    end
  end

  def after_perform_scale_down
    Scaler.workers = 0
  end

  def after_enqueue_scale_up
    Scaler.workers = 1
  end

end