Lists the process to add a role.
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 of 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 previous 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.