Zero Vcores or Cannot access YARN ResourceManager UI

[Pankaj Chand <pa...@gmail.com>]

Hi all,

I have NameNode and ResourceManager on the same single master node, and I
am running experiments on Cloudlab.

I'm facing a problem in Hadoop 2.8.3 where I am either getting 0 vcores in
YARN, or not able to access the YARN UI.

This problem did not happen when I was using Hadoop 2.7.5 and the master
node was named "namenode". I could access the YARN resourceManager UI by
doing:
full-cloudlab-machine-name:8088

When I switched to Hadoop 2.8.3, I named my master node "master" because
that is the same name used in the /etc/hosts file and hadoop masters file.
With the same settings as previously (hadoop 2.7.5), I am getting 0 vcores
in YARN UI, and so applications are not getting deployed.

So, I added in the yarn-site.xml file: yarn.resourcemanager.hostname =
master

Now, I am getting a certain number of vcores and applications are running,
but I am not able to access the ResourceManager UI at either
full-cloudlab-machine-name:8088 nor at master:8088.

Please help.

Thanks,

Pankaj