Finishing the HDFS upgrade process

After you have initiated the HDFS upgrade in the sections above, you will eventually have to decide – hopefully after thorough testing – whether you want to stick to the upgraded HDFS (= your tests were successful) or to revert the HDFS upgrade (= your tests failed). The following two sections describe how to finalize (i.e. stick to) an HDFS upgrade and how to perform a rollback of an HDFS upgrade.