When Hadoop executes start-yarn.sh, it will report an error of “error: attempting to operate on yarn ResourceManager as root”.

Method 1

sudo vim ~/.bashrc

Add the following parameters at the end:

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

Method 2

Add the following parameters at the top of the start-dfs.sh and stop-dfs.sh files:

HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root

Add the following parameters at the top of the start-yarn.sh and stop-yarn.sh files:

YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root

*The above files are in the SBIN directory of the Hadoop root directory.

*The official recommendation is to create a new independent account for yarn to start.