In Components, find a decommissioned component.

Stop the component, if necessary.

	Note
	A decommissioned slave component may restart in the decommissioned state.

For a decommissioned component, choose Delete from the component drop-down menu.

	Note
	Restarting services enables Ambari to recognize and monitor the correct number of components.

Deleting a slave component, such as a DataNode does not automatically inform a master component, such as a NameNode to remove the slave component from its exclusion list. Adding a deleted slave component back into the cluster presents the following issue; the added slave remains decommissioned from the master's perspective. Restart the master component, as a work-around.