To delete a component using Ambari Web, on Hosts choose the host FQDN on which the component resides.
In Components, find a decommissioned component.
Stop the component, if necessary.
![[Note]](../common/images/admon/note.png)
Note A decommissioned slave component may restart in the decommissioned state.
For a decommissioned component, choose Delete from the component drop-down menu.
Restart the Ganglia and Nagios services.
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.
