Ambari support for NameNode Federation

Ambari needs to be able to deploy, manage and monitor HDFS Federation - with 2 or more Federated namespaces.

Hdfs configuration

Each hdfs federated namespace has a namenode, and for each namespace namenode ha can be set up - allowing for multiple journal nodes and active/standby namenode for the namespace. When kerberizing, managing (start/stop/configure) , and monitoring, each namenode needs to be treated as a separate master.