1、执行sbin/start-all.sh或sbin/stop-all.sh报错
ERROR: Attempting to operate on hdfs namenode as root
处理：
在start-dfs.sh，stop-dfs.sh添加：
HDFS_DATANODE_USER=root
HADOOP_SECURE_DN_USER=hdfs
HDFS_NAMENODE_USER=root
HDFS_SECONDARYNAMENODE_USER=root
在start-yarn.sh，stop-yarn.sh添加：
YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root
2、执行sbin/start-all.sh报错
Starting namenodes on [hadoop-master-181.pdl] hadoop-master-181: root@hadoop-master-181: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
处理：
配置SSH
ssh-keygen -t rsa
cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
3、启动Hadoop配置
etc/hadoop/core-site.xml增加:
<property>
<name>hadoop.tmp.dir</name>
<value>/pdldata/hadoop-3.3.0/data/tmp</value>
</property>
<property>
<name>fs.defaultFS</name>
<value>hdfs://10.0.252.181:8020</value>
</property>
etc/hadoop/hdfs-site.xml增加:
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
<property>
<name>dfs.permissions</name>
<value>false</value>
</property>
<property>
<name>dfs.http.address</name>
<value>10.0.252.181:50070</value>
</property>
