I'm having the same problem trying to access Hive from Nifi via Zookeeper. HDFS access from within hive works fine.
I manually installed the clients on my Nifi node (as it's external to my cluster) and copied the core-site and hive-site files over to it. I can connect via beeline (with and without adding 'principal=hive/_HOST@<REALM>' to the connection string. The hive cli throws an error, however. I believe that this error is due to the fact that it's trying to connect remotely to the mysql instance and would need a password (rather than the password less auth on the local hiveserver) which isn't conifgured, so it fails. Caused by: java.sql.SQLException: Access denied for user 'hive'@'<HOSTNAME>' (using password: YES)