In hdp cluster one of the host is down permanently.
What are the prerequisites to remove that host from cluster.
Basically the steps to remove a Node from cluster is described in the following doc. https://docs.hortonworks.com/HDPDocuments/Ambari-188.8.131.52/managing-and-monitoring-ambari/content/amb_...
Before deleting a host, you must:
Stop all components running on the host.
Decommission any DataNodes running on the host.
Move from the host any master components, such as NameNode or ResourceManager, running on the host.
Turn off host Maintenance Mode, if it is on.
However if you have lost a Node which has master components installed in it like HIveMetastore/NameNode/Resource Manager ....etc then the process is bit complex and you might be loosing the data.