To ensure that a NameNode in your cluster is always available if the primary NameNode hosts fails, enable and set up NameNode High Availability on your cluster using Ambari Web. In Admin, select High Availability, then choose Enable NameNode HA. Follow the steps in the Enable NameNode HA Wizard. For more information about using The Enable NameNode HA Wizard to set up NameNode High Availability, see Setting Up NameNode High Availability.
