title: Cassandra out of memory due to frequent GC
body: <p>I had a network level outage during which 8 of my 12 servers went down due to an incorrect nproc hard limit which we tried with 16k.</p>
  <p>Post that we increased it to 32k (hope it's fine with 32 GB RAM) and restarted all the servers. 4 of my servers in one DC seems to go down on a frequent basis due to Out Of Memory continuously. When I inspected the logs,</p>
  <ol>
  <li><p>I found a lot of GC inspector log prints .</p>
  </li>
  <li><p>Each time I shut down the application , the cached memory seems to be still occupied. Do I need to drop the cache and start the application? I did that few times and even then GC never ended. It kept eating the memory and moved towards death. The print that came for GC were starting off with ParNew. Any idea on how to get this fixed?</p>
  </li>
  <li><p>I cleared off the compactions in progress to start off the server a few times they were blocking the restart. This seems to kick off in between each time. Is this a problem? Any idea on how to get this fixed?</p>
  <p>Cassandra version used : 2.0.3</p>
  </li>
  </ol>