title: Why are mapreduce attempts killed due to "Container preempted by scheduler"?
body: <p>I just noticed the fact that many Pig jobs on Hadoop are killed due to the following reason: <code>Container preempted by scheduler</code></p>
  
  <p>Could someone explain me what causes this, and if I should (and am able to) do something about this?</p>
  
  <p>Thanks!</p>