title: YARN UNHEALTHY nodes
body: <p>In our YARN cluster which is 80% full, we are seeing some of the yarn nodemanager's are marked as UNHEALTHY. after digging into logs I found its because disk space is 90% full for data dir. With following error</p>
  
  <pre><code>2015-02-21 08:33:51,590 INFO org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNodeImpl: Node hdp009.abc.com:8041 reported UNHEALTHY with details: 4/4 local-dirs are bad: /data3/yarn/nm,/data2/yarn/nm,/data4/yarn/nm,/data1/yarn/nm;
  2015-02-21 08:33:51,590 INFO org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNodeImpl: hdp009.abc.com:8041 Node Transitioned from RUNNING to UNHEALTHY
  </code></pre>
  
  <p>I am trying to understand how yarn marks node Unhealthy &amp; is there any way to change the threshold ?</p>
  
  <p>Thanks</p>