兩種解決ERROR: Attempting to operate on hdfs namenode as root的方法

描述：hadoop-3.1.0啟動hadoop集群時還有可能可能會報如下錯誤

[root@localhost sbin]# start-all.sh
Starting namenodes on [hadoop]
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 secondary namenodes [hadoop]
ERROR: Attempting to operate on hdfs secondarynamenode as root
ERROR: but there is no HDFS_SECONDARYNAMENODE_USER defined. Aborting operation.
2018-07-16 05:45:04,628 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting resourcemanager
ERROR: Attempting to operate on yarn resourcemanager as root
ERROR: but there is no YARN_RESOURCEMANAGER_USER defined. Aborting operation.
Starting nodemanagers
ERROR: Attempting to operate on yarn nodemanager as root
ERROR: but there is no YARN_NODEMANAGER_USER defined. Aborting operation.

解決方案一：

輸入如下命令，在環境變量中添加下面的配置

vi /etc/profile

然后向里面加入如下的內容

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

輸入如下命令使改動生效

source /etc/profile

解決方案二：

將start-dfs.sh，stop-dfs.sh(在hadoop安裝目錄的sbin里)兩個文件頂部添加以下參數

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

將start-yarn.sh，stop-yarn.sh(在hadoop安裝目錄的sbin里)兩個文件頂部添加以下參數

YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root

參考文章：
https://blog.csdn.net/u013725455/article/details/70147331
https://www.cnblogs.com/zhengna/p/9316424.html

祝大家hadoop之旅順利