10. Finalize the rolling upgrade process

At this point in the process you have upgraded the binaries and metadata for all of your HDP components.

Run your application workloads on the cluster and make sure that your existing workloads function correctly. Do not proceed until you are confident that the cluster is operating to your satisfaction. Once you finalize the rolling upgrade process, you will not be able to revert to your previous version of HDP.

If there are validation issues at this point and you need to downgrade, follow the steps in Downgrading the Cluster, starting with "Downgrade components outside of the cluster."

HDFS backs up files before the upgrade. During the upgrade process, HDFS avoids deleting files (it creates hardlinks for deleted blocks for safety). Once you are satisfied with the upgrade and want to commit to it, run the following command to instruct HDFS to delete the blocks that were marked for deletion and also to perform deletes in the future.

	Caution
	This is irrevocable - you cannot revert back to your previous version of HDP after running this command.

hdfs dfsadmin -rollingUpgrade finalize