使用root配置的hadoop并启动会出现报错

1、使用root配置的hadoop并启动会出现报错

错误：

        Starting namenodes on [master]

        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 [slave1]

        ERROR: Attempting to operate on hdfs secondarynamenode as root

        ERROR: but there is no HDFS_SECONDARYNAMENODE_USER defined. Aborting operation.

解决方法：

         在/hadoop/sbin路径下：
         将start-dfs.sh，stop-dfs.sh两个文件顶部添加以下参数
              HDFS_DATANODE_USER=root
              HADOOP_SECURE_DN_USER=hdfs
              HDFS_NAMENODE_USER=root
              HDFS_SECONDARYNAMENODE_USER=root
         start-yarn.sh，stop-yarn.sh顶部也需添加以下
            YARN_RESOURCEMANAGER_USER=root
            HADOOP_SECURE_DN_USER=yarn
            YARN_NODEMANAGER_USER=root

2、添加1后出现以下错误

WARNING: HADOOP_SECURE_DN_USER has been replaced by HDFS_DATANODE_SECURE_USER. Using value of HADOOP_SECURE_DN_USER.
Starting namenodes on [mylinux_1]
mylinux_1: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Starting datanodes
localhost: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Starting secondary namenodes [mylinux_1]
mylinux_1: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
2018-11-26 09:32:18,082 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting resourcemanager
Starting nodemanagers
localhost: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).

解决办法：配置免密登录（注意：对本机也需要配置）

ssh-keygen -t rsa

ssh-copy-id -i ~/.ssh/id_rsa.pub root@MyLinux_1