Created on 12-10-201907:56 AM - edited on 12-23-202002:29 AM by VidyaSargur
To ensure that another NameNode in a cluster is always available when an active NameNode host fails, the NameNode high availability should be enabled and configured on the cluster from the Ambari Web User Interface.
This video explains how to enable HA wizard and the steps that must be followed to set up NameNode high availability.
If the HDFS or ZooKeeper services are inMaintenance Modethe NameNode HA wizard will not complete successfully.
HDFS and ZooKeeper must be stopped and started when enabling NameNode HA as theMaintenance Modewill prevent those start and stop operations from occurring.