Removing Roles from a Node

You can remove roles from nodes in the MapR cluster. The process of removing a role from a node depends on the role type.

Once you remove a role from a node, you must restart Warden. Observe the following best practices when restarting Warden on nodes that were ZooKeeper or CLDB nodes:
  • Perform a rolling restart of Warden to ensure that all services are up. A rolling restart of Warden means restart Warden on each node, one at a time, pausing until the last restart finishes before beginning the next.
  • To avoid a failover from occurring, identify nodes running critical services, such as ResourceManager, and restart Warden last on those nodes.
  • Restart Warden on nodes that run critical cluster services, such as ResourceManager, during periods of low activity.