title: Cassandra 2.2.3 repair exception
body: <p>I'm running a Cassandra cluster with version 2.2.3. The cluster consists of 3 nodes now, two of them are seeds and one is a normal node.</p>
  
  <p>When I start repair on each node (command: <code>nodetool repair -tr my_keyspace</code>), I found the command was blocked on each node, I redirect the trace back information to the log and found there are many errors like the following:</p>
  
  <blockquote>
    <p>Session completed with the following error:   org.apache.cassandra.exceptions.RepairException: [repair #5717bb00-e685-11e5-801e-c71692f88562 on my_keyspace/node,   (4856831381680181267,4878966233072304148]] Validation failed in /10.16.170.20</p>
  </blockquote>
  
  <p>Has anyone faced the error before? Can we run Cassandra nodetool repair parallelly on each node?</p>