Adding Roles to a Node

You can add roles on a node after you deploy the node in a cluster. The process of adding a role to a node involves installing a package on the node and updating the cluster to recognize the new role. The process for adding a role depends on the role type.

Once you have added a role to a node, you must restart Warden. Observe the following best practices when restarting Warden on ZooKeeper and 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.