title: Cassandra dies with Out of memory: Kill process or sacrifice child
body: <p>We have a 6 node cluster, running: </p>
  
  <ul>
  <li>Cassandra 3.11.0.1900</li>
  <li>DSE 5.1.5</li>
  <li>Ubuntu 16.04.4 LTS</li>
  <li>java-1.8.0-openjdk-amd64 </li>
  </ul>
  
  <p>One of the nodes dies with the following message in syslog: </p>
  
  <blockquote>
    <p>[1770962.274743] Out of memory: Kill process 49468 (java) score 893 or
    sacrifice child [1770962.299330] Killed process 49468 (java)
    total-vm:1156754248kB, anon-rss:46906424kB, file-rss:176871432kB</p>
  </blockquote>
  
  <p>Swap is disabled on the node, and <code>/proc/sys/vm/overcommit_memory</code> is set to 0. Note that this happens when <code>/proc/sys/vm/overcommit_memory</code> is set to 1 also. </p>
  
  <p>Unfortunately, there are no related error messages in the Cassandra <code>system.log</code> (we are logging at level debug). </p>
  
  <p>Any ideas as to what could be causing this behavior?</p>