title: Celery task chain cancelling?
body: <p>I found that celery supports task chains: <a href="http://celery.readthedocs.org/en/latest/userguide/canvas.html#chains">http://celery.readthedocs.org/en/latest/userguide/canvas.html#chains</a>.</p>
  
  <p>Question is: <strong>how can I stop chain's execution in a task?</strong></p>
  
  <p>For example, we got a chain of N items (N > 2). And in the second task we realize that we do not need all the rest tasks to be executed. What to do?</p>