title: How can I approach ruby background worker
body: <p>I am creating a stock market game on rails. Here I have a scenario where I want explore what are different approaches in running background jobs in ruby.</p>
  
  <p>Scenario:
  This application will have users. User will add other users as friends. Now my application will compare scores of these users and will send email to the user, if his/her friend is performing better than him/her to inspire him/her. Again app will be sending emails to user if he hasn't logged in in last 2 weeks. So mail triggers are away duration (> 2weeks) and user and their friends score comparison.</p>
  
  <p>Points of discussion:</p>
  
  <ul>
  <li><p>I have briefly gone through Delayed_job, Resque. What would be the
  best library?</p></li>
  <li><p>If I want write a cron job in shell or other language will be more
  fast as in performance?</p></li>
  <li><p>Does above library uses separate processes for each queue or they use
  separate threads.</p></li>
  </ul>
  
  <p>Please advice me on how should I approach this scenario.</p>
  
  <p>Thanks in advance!</p>