title: why lost some data after nodetool cleanup in cassandra
body: <p>We added a new node to datacenter and then run <code>nodetool cleanup</code> according to <a href="http://docs.datastax.com/en/cassandra/3.0/cassandra/operations/opsAddNodeToCluster.html" rel="nofollow noreferrer">Add new node to existing cluster in cassandra</a>.  But after cleanup completed, we noticed that we lost some data.</p>
  
  <p>What could be the reason?</p>