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.
$ 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
I tried solutions at this stackoverflow question, which is very similar to my problem. But nothing worked out. A problem same as mine is posted in another forum here. However, no solution is available there as well.
Then, I tried another option which I am describing in the following text. I set following exports in the file sbin/start-yarn.sh.
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"
Then executed with sbin/start-yarn.sh and I got the following error. Please note that I have done all the settings for passwordless ssh for root@localhost.
$ 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
In addition to the steps suggested by zhao, ephraimbuddy and qitian. Please make sure that if you have a firewall running than the firewall is not blocking it in anyway. Also make sure that the user with which you are executing the command has enough permissions to update the priorities.