hadoop fs -ls does not work

Question

I have installed a single node Hadoop on my local computer with Ubuntu 14.04 OS. Now I am going to use HDFS, and when I type a simple command

hdu@hadoop:~$ hadoop fs -ls

it shows up the following errors:

15/07/10 18:24:52 WARN util.NativeCodeLoader: 
Unable to load native-hadoop library for your platform... 
using builtin-java classes where applicable
ls: Call From hadoop/127.0.1.1 to 
localhost:9000 failed on connection exception: 
java.net.ConnectException: 
Connection refused; For more details see:
http://wiki.apache.org/hadoop/ConnectionRefused

I have no ideas about this error, and I really appreciate if anyone helps me fix the problem :)

Thanks for your reply! Yeah, I also tried that, and it seems the same error... — Ruofan Kong, Jul 10 '15 at 22:58
are you table brows this ..? http://localhost:50070/dfshealth.jsp — rbyndoor, Jul 10 '15 at 22:59
Thank you so much!!! The main reason that my hadoop fs does not work is because I did not start my namenode service although I formatted it. Now my problem is solved :) — Ruofan Kong, Jul 12 '15 at 20:50

score 1 · Accepted Answer · answered Jul 11 '15 at 04:49

1

Did you actually start your namenode service? Formatting the namenode doesn't actually start the namenode service. If your namenode service is running then perhaps you are running into the Ubuntu issue referenced in the link in the error.

From: http://wiki.apache.org/hadoop/ConnectionRefused

Check that there isn't an entry for your hostname mapped to 127.0.0.1 or 127.0.1.1 in /etc/hosts (Ubuntu is notorious for this)

answered Jul 11 '15 at 04:49

Cody Stevens

424
4
9

The answer is really helpful! I think my problem mainly comes from not starting my namenode service although I formatted it. Now the problem is solved. Thanks a lot for your great answer!!! – Ruofan Kong Jul 12 '15 at 20:52

score 1 · Answer 2 · answered Jul 14 '15 at 02:50

1

You can try these commands!

# su - hadoop
$ cd /opt/hadoop/hadoop
$ bin/hadoop namenode -format

$ bin/start-all.sh

answered Jul 14 '15 at 02:50

Rachit Ahuja

371
2
15

Thanks for your answers! Currently, my problem has already been solved. But anyway, thanks a lot!!! – Ruofan Kong Jul 14 '15 at 15:25

hadoop fs -ls does not work

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