1、使用root配置的hadoop并启动会出现报错

[root@iZbp153yczpm4pp9pjs0u3Z sbin]# start-all.sh 
Starting namenodes on [hdp-01]
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 [47.96.106.223]
ERROR: Attempting to operate on hdfs secondarynamenode as root
ERROR: but there is no HDFS_SECONDARYNAMENODE_USER defined. Aborting operation.
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：

#!/usr/bin/env bash
HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root

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

#!/usr/bin/env bash
YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root

重新开始start...就可以。

2.报错

[root@iZbp153yczpm4pp9pjs0u3Z sbin]# start-all.sh 
Starting namenodes on [hdp-01]
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 [47.96.106.223]
ERROR: Attempting to operate on hdfs secondarynamenode as root
ERROR: but there is no HDFS_SECONDARYNAMENODE_USER defined. Aborting operation.
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.

解决方法：

创建服务器与服务器之间免密登陆

命令：ssh-copy-id -i ~/.ssh/id_rsa.pub [romte_ip]

如下

[root@iZbp153yczpm4pp9pjs0u3Z .ssh]# ssh-copy-id -i ~/.ssh/id_rsa.pub 47.96.106.223
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@47.96.106.223's password: 
[root@iZbp153yczpm4pp9pjs0u3Z .ssh]# ssh-copy-id -i ~/.ssh/id_rsa.pub 47.96.106.223
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@47.96.106.223's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh '47.96.106.223'"
and check to make sure that only the key(s) you wanted were added.

重新开始start…就可以。