title: Hadoop namenode : Single point of failure
body: <p>The Namenode in the Hadoop architecture is a single point of failure. </p>
  
  <p><em>How do people who have large Hadoop clusters cope with this problem?.</em></p>
  
  <p><em>Is there an industry-accepted solution that has worked well wherein a secondary Namenode takes over in case the primary one fails ?</em></p>