Some months ago we adopted delayed_job as our asynchronous background processor. In Realized-app several tasks, particularly tax lot setup, benefit from background processing.

Taking the advice from this blog post on GitHub, we reduced the coupling between models and the message queue by placing the background methods in lib/msg_queue.rb.

module MsgQueue

  class UserActivationConfirm < Struct.new(:user_id)

    def perform

      user = User.find(user_id)

      user.activation_confirmation_email

    end

    . . .

We create the corresponding delayed job in models/user.rb.

class User

  def activation_confirmation_mq

    mq = MsgQueue::UserActivationConfirm.new(id)

    Delayed::Job.enqueue(mq)

  end

end

The call to Job#enqueue remains within each model to allow for passing a priority parameter, should that be needed.

Deployment on Heroku

Heroku began limited support for delayed_job in July. Yesterday Heroku broadened that support with a new feature that provides for multiple delayed_job workers per app. That capability sealed our decision to deploy, at least initially, on Heroku.