title: When do I need to run nodetool upgradesstables while upgrading multimode cluster?
body: <p>I am in process of upgrading Cassandra from 2.0.9 to 2.1.14.  In the upgrade instructions, it says we should run <code>nodetool upgradesstables</code> after the upgrade process.</p>
  
  <p>I have 12 nodes in my cluster.  When I start the upgrade process on a node, do I need to run <code>nodetool upgradesstables</code> on that node after starting it with the new version?  Or after all nodes have been upgraded to the new version?</p>