@Vivek Sabha Once your setup is correctly you can switch the standby to primary. I hope you have successfully moved your old standby to the new host and validated that indeed its taken over the role of standby ! If you have set up automatic failover with ZooKeeper Failover Controllers then the ZKFC processes will automatically transition the Standby NN to Active status if the current active is unresponsive.The cluster failover is automatically done by Ambari. If you want to make your standby namenode the active one, you can stop the current active namenode (ensuring the current standby namenode is alive) and the current standby namenode will take over as the active namenode. ... View more