Let’s say you need to run the distcp command:
hadoop distcp -Dmapreduce.map.memory.mb=1000 -m 200 hdfs://node1:8020/your/folder1 hdfs://node1:8020/your/folder2
But as a result, you get an error like this:
ERROR tools.DistCp: Invalid arguments: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.ipc.StandbyException): Operation category READ is not supported in state standby. Visit https://s.apache.org/sbnn-error
One of the non-obvious reasons for such an error may be that node1:8020 is not an active node. Recheck the hostname and run the command again.
If you still have any questions, feel free to ask me in the comments under this article, or write me on firstname.lastname@example.org.