title: hadoop replication factor confusion
body: <p>We have 3 settings for hadoop replication namely:</p>
  
  <pre><code>dfs.replication.max = 10
  dfs.replication.min = 1
  dfs.replication     = 2
  </code></pre>
  
  <p>So dfs.replication is default replication of files in hadoop cluster until a hadoop client is setting it manually using "<strong>setrep</strong>".
  and a hadoop client can set max replication up to <strong>dfs.replication.mx</strong>.</p>
  
  <p>dfs.relication.min is used in two cases:</p>
  
  <ol>
  <li>During safe mode, it checks whether replication of blocks is upto <strong>dfs.replication.min</strong> or not.</li>
  <li><strong>dfs.replication.min</strong> are processed synchronously. and remaining dfs.replication-dfs.replication.min are processed asynchronously.</li>
  </ol>
  
  <p>So we have to set these configuration on each node (namenode+datanode) or only on client node?</p>
  
  <p>What if setting for above three settings vary on different datanodes?</p>