Decommission a host

Decommissioning is a process that supports removing components and their hosts from the cluster.

You must decommission a master or slave running on a host before removing it or its host from service. Decommissioning helps you to prevent potential loss of data or disruption of service. Decommissioning is available for the following component types:

• DataNodes

• NodeManagers

• RegionServers

Decommissioning executes the following tasks:

For DataNodes

Safely replicates the HDFS data to other DataNodes in the cluster

For NodeManagers

Stops accepting new job requests from the masters and stops the component

For RegionServers

Turns on drain mode and stops the component