Delete the additional NameNode
You may need to delete your additional NameNode.
Check to see if you need to delete your Additional NameNode,
on the Ambari Server host:
curl -u [AMBARI_USER]:[AMBARI_PW] -H "X-Requested-By: ambari" -i -X GET
[AMBARI_PROTO]://localhost:[AMBARI_PORT]/api/v1/clusters/[CLUSTER_NAME]/host_components?HostRoles/component_name=NAMENODE
If the items array contains two NameNodes, the Additional NameNode must be deleted.