title: Difference between expected_nodes and recover_after_nodes parameters
body: <p>I can't see the difference between two parameters for the recovery phase of the gateway module.</p>
  
  <p>In the <a href="http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/modules-gateway.html#recover-after">documentation</a> :</p>
  
  <ul>
  <li><p>The <code>gateway.recover_after_nodes</code> setting (which accepts a number) controls <strong>after how many (...) eligible nodes (...) recovery will start</strong>.</p></li>
  <li><p>The <code>gateway.expected_nodes</code> allows to set <strong>how many (...) eligible nodes</strong> are expected to be in the cluster, and <strong>once met, (...) recovery starts</strong></p></li>
  </ul>
  
  <p>From what I understand, these two settings trigger the recovery phase once the number of node is equal to the value set.</p>
  
  <p>Why using one over the other? </p>
  
  <p>And what is the point of using both of them? </p>
  
  <p>For example :</p>
  
  <pre><code>gateway:
      recover_after_nodes: 3
      expected_nodes: 5
  </code></pre>
  
  <p>In this case, what is the purpose of <code>expected_nodes</code>? recovery will be triggered as soon as there will be 3 nodes. There must be another reason to use it.</p>
  
  <p>I hope my question is clear enough.</p>
  
  <p>Thanks in advance!</p>