What could be the issue with my installation? I am running an example jar file to check my installation and it fails.

[#1]

I am running the following example jar file

sudo yarn jar /usr/hdp/2.3.6.0-3796/hadoop-mapreduce/hadoop-mapreduce-examples-2.7.1.2.3.6.0-3796.jar wordcount /data/input/word.txt /data/out

But it gives some connection failed error.

INFO client.RMProxy: Connecting to ResourceManager at hadoop.localdomain/127.0.1.1:8050

Retrying connect to server: hadoop.localdomain/127.0.1.1:8050.

Here is something from the log /var/log/hadoop-yarn/yarn/yarn-yarn-resourcemanager-hadoop.log

INFO zookeeper.ClientCnxn (ClientCnxn.java:logStartConnect(1019)) - Opening socket connection to server hadoop.localdomain/127.0.1.1:2181.

I know i need RM to run a mapreduce job.

Now i checked and i found from ambari gui that my resource manager is also not working.

I have one confusion. in yarn-site.xml file the value for yarn resource is using the hadoop.localdomain which points to 127.0.1.1 in the host file.

<name>hadoop.registry.zk.quorum</name> <value>hadoop.localdomain:2181</value>

I am not sure if this hadoop.localdomain is the right hostname since it points to 127.0.1.1 and i can only access the ambari gui through my browser at 192.130.3.21:8080

ubuntu@hadoop:~$ more /etc/hosts 127.0.0.1 localhost 192.130.3.21 localhost2 127.0.1.1 hadoop.localdomain hadoop # 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 ff02::3 ip6-allhosts

I am able to access the ambari using the ip 192.130.3.21:8080

Does anyone know what show be the configuration(hadoop.localdomain or else). I dont know what is wrong here.

[#2]

@irfan aziz

Can you please check your resource manager logs to see what went wrong? log location would be(by default) /var/log/hadoop-yarn/yarn/yarn-yarn-resourcemanager-<hostname>.log

You can post the error here if you need any further help!

[#3 · Accepted solution]

@irfan aziz

Your hostname "hadoop.localdomain hadoop" should always point the proper IP address of your server in /etc/hosts. I think you have a problem with your /etc/hosts file. I expect it should look more like this:

127.0.0.1  localhost
127.0.1.1  localhost2
192.130.3.21 hadoop.localdomain hadoop

Can you confirm that is what your /etc/hosts file actually looks like?

[#4]

I would also second what Kuldeep has mentioned. The /etc/hosts does not look right, but the fact that the RM as well as the NM is down at the same time needs to be looked into. Please upload the snippet of the logs which has the error stack which will help us isolate into the root cause of the issue here

[#5]

@Kuldeep Kulkarni @Sumesh @Michael Young

Thank you guys the issue was with the host file . Since i am using cloud server that has two ip and...

[#6]

Thank you so much @irfan aziz for the confirmation. I'm accepting answer given by @Michael Young. Please feel free to accept appropriate answer if required.