title: Celery: Redis as broker leaving task meta keys
body: <p>I have celery app with Redis as broker.</p>
  
  <p>The code consist of the following in a loop :</p>
  
  <pre><code>running = []
  res = add.apply_async([1,2], queue='add')
  running.append(res)
  
  while running:
      r = running.pop()
      if r.ready():
          print r.get()
      else:
          running.insert(0,r)
  </code></pre>
  
  <p>everything works fine but when i <code>redis-cli</code> into redis and execute <code>keys *</code>
  I see bunch of celery-task-meta keys.</p>
  
  <p>Why arent they cleaned up?<br>
  What are those for?  </p>
  
  <p>--</p>
  
  <p>[EDIT]</p>
  
  <p>I've read about CELERY_TASK_RESULT_EXPIRES setting.<br>
  Is it possible for the task keys in Redis to be cleaned up right after the result is read rather than wait until the expiration time?</p>