You can check the ports with netstat -anp | grep 9000 before and after the change in the ufw ... View more

Solution worked for me -> firewall was the reason on 64bit Ubunu 16.04 "sudo ufw allow 9000" changes the rules, then namenode listens with master:9000 ... View more

Would you please tell us how did you change localhost:9000 to master:9000. in core-site it is addressing master:9000. Why it picks 127.0.0.1? Which file I should make changes? ... View more