Ensure that you prepare the following hardware resources:
ResourceManager nodes: The nodes where you run Active and Standby ResourceManagers should have exactly the same hardware. For recommended hardware for ResourceManagers, see "Hardware for Master Nodes" in the Cluster Planning Guide.
Zookeeper machines: For automated failover functionality, there must be an existing Zookeeper cluster available. The Zookeeper service nodes can be co-located with other Hadoop daemons.
