title: Hadoop: Cannot set priority of resourcemanager process
body: <p>I am very new to hadoop and am trying to set a psuedo-distributed mode execution with Hadoop-3.1.2.
  When I try to start yarn service I get the following error, please see the code snippet below. </p>
  
  <pre><code>$ sbin/start-yarn.sh 
  Starting resourcemanagers on []
  localhost: ERROR: Cannot set priority of resourcemanager process 13209
  pdsh@manager-4: localhost: ssh exited with exit code 1
  Starting nodemanagers
  localhost: ERROR: Cannot set priority of nodemanager process 13366
  pdsh@manager-4: localhost: ssh exited with exit code 1
  </code></pre>
  
  <p>I tried solutions at <a href="https://stackoverflow.com/questions/46283634/localhost-error-cannot-set-priority-of-datanode-process-32156">this</a> stackoverflow question, which is very similar to my problem. But nothing worked out. A problem same as mine is posted in another forum <a href="https://developer.ibm.com/answers/questions/486770/resource-manager-is-not-starting-on-both-master-an/" rel="nofollow noreferrer">here</a>. However, no solution is available there as well.</p>
  
  <p>Then, I tried another option which I am describing in the following text.
  I set following <em>exports</em> in the file <em>sbin/start-yarn.sh</em>.</p>
  
  <pre><code>export HDFS_NAMENODE_USER="root"
  export HDFS_DATANODE_USER="root"
  export HDFS_SECONDARYNAMENODE_USER="root"
  export YARN_RESOURCEMANAGER_USER="root"
  export YARN_NODEMANAGER_USER="root"
  </code></pre>
  
  <p>Then executed with <em>sbin/start-yarn.sh</em> and I got the following error. Please note that I have done all the settings for passwordless ssh for root@localhost.</p>
  
  <pre><code>$ sudo sbin/start-yarn.sh
  Starting resourcemanagers on []
  localhost: Permission denied (publickey).
  pdsh@manager-4: localhost: ssh exited with exit code 255
  Starting nodemanagers
  localhost: Permission denied (publickey).
  pdsh@manager-4: localhost: ssh exited with exit code 255
  </code></pre>