hadoop3.2.2 ERROR: but there is no HDFS_NAMENODE_USER defined. Aborting operation. Starting datanodes

错误描述：

[root@nna hadoop-3.2.2]# start-dfs.sh
Starting namenodes on [nna nns]
ERROR: Attempting to operate on hdfs namenode as root
ERROR: but there is no HDFS_NAMENODE_USER defined. Aborting operation.
Starting datanodes
ERROR: Attempting to operate on hdfs datanode as root
ERROR: but there is no HDFS_DATANODE_USER defined. Aborting operation.
Starting journal nodes [dn1 dn3 dn2]
ERROR: Attempting to operate on hdfs journalnode as root
ERROR: but there is no HDFS_JOURNALNODE_USER defined. Aborting operation.
Starting ZK Failover Controllers on NN hosts [nna nns]
ERROR: Attempting to operate on hdfs zkfc as root
ERROR: but there is no HDFS_ZKFC_USER defined. Aborting operation.
[root@nna hadoop-3.2.2]# jps
2457 NameNode
2778 Jps
[root@nna hadoop-3.2.2]#

解决方法：

在Hadoop安装目录下找到sbin文件夹

在里面修改四个文件

1、对于start-dfs.sh和stop-dfs.sh文件，添加下列参数：

HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root

2、对于start-yarn.sh和stop-yarn.sh文件，添加下列参数：

YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root