Preparing the Hardware Resources
Make sure that you prepare the hardware resources before configuring the Resource Manager for High Availability.
ResourceManager machines: The machines 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.