At this stage, the following components have been upgraded and need to be downgraded:
Core slave nodes: DataNodes, NodeManager, RegionServer
Core masters: HDFS, YARN, HBase
Ranger
Zookeeper
Downgrade these processes as a set, one node at a time, before proceeding to the next node:
Downgrade HDFS DataNode, if present
Downgrade YARN NodeManager, if present
Downgrade HBase RegionServer, if present
