Question - When do you use the dfsadmin -refreshNodes and rmadmin -refreshNodes commands?
Answer -
The commands below are used to refresh the node information while commissioning, or when the decommissioning of nodes is completed.
dfsadmin -refreshNodes
This is used to run the HDFS client and it refreshes node configuration for the NameNode.
rmadmin -refreshNodes
This is used to perform administrative tasks for ResourceManager.