3. Deploy HA Cluster

HA configuration is backward compatible and works with your existing single NameNode configuration.

[Note]Note

These instructions provide information on setting up NameNode HA on a manually installed cluster. If you installed with Ambari and manage HDP 2.0 on Ambari 1.4.1 or later, use the Ambari documentation for the NameNode HA wizard instead of these instructions.

First, enable the NameNodes to share metadata through QJM. Then, enable automatic failover through Zookeeper.