Role Instances Adding a Role InstanceStarting, Stopping, and Restarting Role InstancesDecommissioning Role InstancesYou can remove a role instance such as a DataNode from a cluster while the cluster is running by decommissioning the role instance. Recommissioning Role InstancesDeleting Role InstancesConfiguring Roles to Use a Custom Garbage Collection ParameterYou can use Java configuration options to configure roles to use a custom garbage collection parameter. Parent topic: Managing Roles