Rails help creating a delayed_job from a rake file

问题:

How do I create a delayed job from a rake file. How should I move it into a controller and create a delayed_job that runs the task every 15 minutes.

Here is an example how my rake file:

namespace :reklamer do

    task :runall => [:iqmedier, :euroads, :mikkelsen] do
      # This will run after all those tasks have run
    end

      task :iqmedier => :environment do
              require 'Mechanize'
              agent = WWW::Mechanize.new
              agent.get("http://www.iqmedier.dk")
      end
      task :euroads => :environment do
            require 'Mechanize'
            require 'pp'
            agent = Mechanize.new { |agent|
      end

      task :mikkelsen => :environment do
            require 'Mechanize'
            agent = Mechanize.new
            agent.get("http://affilate.mikkelsenmedia.dk/partnersystem/mylogins.php")
       end
    end

What should I change to be a delayed job (https://github.com/collectiveidea/delayed_job)?

回答1:

Suggest you take a look at SimpleWorker, a cloud-based background processing / worker queue for Ruby apps. It's designed for offloading tasks, running scheduled jobs, and scaling out to handle many parallel jobs at once. It's simple, affordable, and scalable.

(Disclosure, I work for the company.)

You create your workers (in app/worker) and then in your controllers and elsewhere queue them up to run right away or schedule them for later or on a recurring basis with just a few lines of code. Here's a basic example.

  worker = ReportWorker.new
  worker.user_id = @current_user.id
  worker.schedule(:start_at => 1.hours.since, :run_every => 900)

  #Or to run once right away
  #worker.queue

The ReportWorker class would contain the logic to create the report for the current user and sent it or post it needed.

回答2:

DelayedJob alone will not help you since it is based around one-time jobs. You will still need something that runs on a regular basis that creates these jobs.

Assuming:

1. you're on Heroku and can only get a 1-hour cron
2. you need to run a job every 15 minutes

You can do something like this...

Make a class for your jobs:

class MechanizeJob < Struct.new(:url)
  def perform
    agent = Mechanize.new
    agent.get(url)
  end
end

Schedule the jobs from your Rakefile:

task :schedulejobs => :environment do
  urls = ["http://...", "http://...", "http://..."]
  urls.each do |url|
    # 1 is the job priority
    Delayed::Job.enqueue MechanizeJob.new(url), 1, Time.now
    Delayed::Job.enqueue MechanizeJob.new(url), 1, 15.minutes.from_now
    Delayed::Job.enqueue MechanizeJob.new(url), 1, 30.minutes.from_now
    Delayed::Job.enqueue MechanizeJob.new(url), 1, 45.minutes.from_now
  end
end

This will run a job per url every 15 minutes.