unable to check nodes on hadoop [Connection refused] - hadoop

Question

If I type http://localhost:50070 or http://localhost:9000 to see the nodes,my browser shows me nothing I think it can't connect to the server.
I tested my hadoop with this command:
hadoop jar hadoop-*test*.jar TestDFSIO -write -nrFiles 10 -fileSize 1000
but too didn't work and it tries to connect to the server,this is the output:
12/06/06 17:25:24 INFO mapred.FileInputFormat: nrFiles = 10
12/06/06 17:25:24 INFO mapred.FileInputFormat: fileSize (MB) = 1000
12/06/06 17:25:24 INFO mapred.FileInputFormat: bufferSize = 1000000
12/06/06 17:25:25 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 0 time(s).
12/06/06 17:25:26 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 1 time(s).
12/06/06 17:25:27 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 2 time(s).
12/06/06 17:25:28 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 3 time(s).
12/06/06 17:25:29 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 4 time(s).
12/06/06 17:25:30 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 5 time(s).
12/06/06 17:25:31 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 6 time(s).
12/06/06 17:25:32 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 7 time(s).
12/06/06 17:25:33 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 8 time(s).
12/06/06 17:25:34 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:9000. Already tried 9 time(s).
java.net.ConnectException: Call to localhost/127.0.0.1:9000 failed on connection exception: java.net.ConnectException: Connection refused
I changed some files like this:
in conf/core-site.xml:
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
in conf/hdfs-site.xml:
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
</configuration>
in conf/mapred-site.xml:
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
</configuration>
Thanks for your attention. If I run this command:
cat /etc/hosts
I see:
127.0.0.1 localhost
127.0.1.1 ubuntu.ubuntu-domain ubuntu
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
and if i run this one:
ps axww | grep hadoop
I see this result:
2170 pts/0 S+ 0:00 grep --color=auto hadoop
but no effect. Have you any idea, how can I solve my problem?

Answer 1

There are few things that you need to take care of before starting hadoop services.
Check what this returns:
hostname --fqdn
In your case this should be localhost.
Also comment out IPV6 in /etc/hosts.
Did you format the namenode before starting HDFS.
hadoop namenode -format
How did you install Hadoop. Location of log files will depend on that. Usually it is in location "/var/log/hadoop/" if you have used cloudera's distribution.
If you are a complete newbie, I suggest installing Hadoop using Cloudera SCM which is quite easy. I have posted my approach in installing Hadoop with Cloudera's distribution.
Also
Make sure DFS location has a write permission. It usually sits # /usr/local/hadoop_store/hdfs
That is a common reason.

Answer 2

same problem i got and this solved my problem:
problem lies with the permission given to the folders
"chmod" 755 or greater for the folders
/home/username/hadoop/*

Answer 3

Another possibility is the namenode is not running.
You can remove the HDFS files:
rm -rf /tmp/hadoop*
Reformat the HDFS
bin/hadoop namenode -format
And restart hadoop services
bin/hadoop/start-all.sh (Hadoop 1.x)
or
sbin/hadoop/start-all.sh (Hadoop 2.x)

Answer 4

also edit your /etc/hosts file and change 127.0.1.1 to 127.0.0.1...proper dns resolution is very important for hadoop and a bit tricky too..also add following property in your core-site.xml file -
<property>
<name>hadoop.tmp.dir</name>
<value>/path_to_temp_directory</value>
</property>
the default location for this property is /tmp directory which get emptied after each system restart..so you loose all your info at each restart..also add these properties in your hdfs-site.xml file -
<property>
<name>dfs.name.dir</name>
<value>/path_to_name_directory</value>
</property>
<property>
<name>dfs.data.dir</name>
<value>/path_to_data_directory</value>
</property>

Answer 5

I am assuming that is your first installation of hadoop.
At the beginning please check if your daemons are working. To do that use (in terminal):
jps
If only jps appears that means all daemons are down. Please check the log files. Especially the namenode. Log folder is probably somewhere there /usr/lib/hadoop/logs
If you have some permission problems. Use this guide during the installation.
Good installation guide
I am shooting with this explanations but these are most common problems.

Answer 6

Hi Edit your core conf/core-site.xml and change localhost to 0.0.0.0. Use the conf below. That should work.
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://0.0.0.0:9000</value>
</property>