Decommission a Component
To decommission a component (a DataNode, in the following example):
Steps
Using Ambari Web, browse the Hosts page.
Find and click the FQDN of the host on which the component resides.
Using the Actions control, click Selected Hosts > DataNodes > Decommission:
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The UI shows Decommissioning status while in process:
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When this DataNode decommissioning process is finished, the status display changes to Decommissioned (shown here for NodeManager).