I have 6 nodes cluster running as non-ha with Namenode-secondardynamenode and I want to upgrade it to HA.
How to upgrade NameNode-SecondardyNode to NameNode-standbyNode(HA) in the existing cluster?
It is very simple just login to Ambari UI and then click on the following action:
Ambari UI --> HDFS --> "Service Actions" drop down menu at right --> "Enable NameNode HA"
And the following the on screen instructions via ambari wizards.
Good to know that the info provided above helped. It will be great if you can mark this thread as Answered by clicking on the "Accept" link on the answer if you got the direction which you were looking out for. That way it will be helpful for other HCC users to quickly find the solution.