Login as $YARN_USER, then run the following command from the ResourceManager server:

su -l yarn -c "/usr/hdp/current/hadoop-yarn-resourcemanager/sbin/yarn-daemon.sh --config $HADOOP_CONF_DIR start resourcemanager"

Login as $YARN_USER, then run the following command from all NodeManager nodes:

su - l yarn -c "/usr/hdp/current/hadoop-yarn-nodemanager/sbin/yarn-daemon.sh --config $HADOOP_CONF_DIR start nodemanager"

where: $HADOOP_CONF_DIR is the directory for storing the Hadoop configuration files. For example, /etc/hadoop/conf.