title: How do I kill running map tasks on Amazon EMR?
body: <p>I have a job running using Hadoop 0.20 on 32 spot instances.  It has been running for 9 hours with no errors.  It has processed 3800 tasks during that time, but I have noticed that just two tasks appear to be stuck and have been running alone for a couple of hours (apparently responding because they don't time out).  The tasks don't typically take more than 15 minutes.  I don't want to lose all the work that's already been done, because it costs me a lot of money.  I would really just like to kill those two tasks and have Hadoop either reassign them or just count them as failed.  Until they stop, I cannot get the reduce results from the other 3798 maps!</p>
  
  <p>But I can't figure out how to do that.  I have considered trying to figure out which instances are running the tasks and then terminate those instances, but </p>
  
  <ol>
  <li>I don't know how to figure out which instances are the culprits</li>
  <li>I am afraid it will have unintended effects.</li>
  </ol>
  
  <p>How do I just kill individual map tasks?</p>