title: How to check progress of ElasticSearch's Reindex API
body: <p>I'm trying to execute a reindex operation from remote ES 2.4 cluster via <strong>Reindex API</strong>. Which job is to transfer more then 100 million docs of an index to latest version of elasticsearch.</p>
  <p>For the test case i'm trying it on small data set but i'm facing following issues.</p>
  <p><strong>issue:</strong></p>
  <ol>
  <li><p>I can't see the progress of the of the script that how many docs are
  transfered and how many left.</p>
  </li>
  <li><p>In case of failure, How can i resume the script instead of
  restarting again from 0.</p>
  </li>
  </ol>