title: Datanode having trouble with JVM pausing
body: <p>I am on CDH 5.1.2, I am seeing this error with one of the datanode pausing often. i see this from logs.</p>
  
  <pre><code> WARN org.apache.hadoop.util.JvmPauseMonitor: Detected pause in JVM or host machine (eg GC): pause of approximately 12428ms
  GC pool 'ConcurrentMarkSweep' had collection(s): count=1 time=12707ms
  </code></pre>
  
  <p>Any Idea why i am seeing this? once a while hdfs capacity is dropping by one node.</p>