title: Two threads in initializer on rails not working
body: <p>Initially I was using one thread to listen a queue from amazon and works perfectly.</p>
  
  <p><img src="https://i.stack.imgur.com/9FJV2.png" alt="enter image description here"></p>
  
  <p><strong>aws.rb</strong></p>
  
  <pre><code>Thread.new do
      queue = AWS::SQS::Queue.new(SQSADDR['my_queue'])
      queue.poll do |msg|
      ...
  </code></pre>
  
  <p>but now I appended another thread to listen another queue:</p>
  
  <pre><code>...    
  Thread.new do
      queue = AWS::SQS::Queue.new(SQSADDR['my_another_queue'])
      queue.poll do |msg|
      ...
  </code></pre>
  
  <p>and now it seems to not work. Only the last one receives response...</p>
  
  <p>What is going on?</p>