一.start-dfs.sh（开启不成功）
原因：1.dadoop 文件所属者 与 执行时 登陆者不一致（权限不足）
报错：
WARNING: HADOOP_SECURE_DN_USER has been replaced by HDFS_DATANODE_SECURE_USER. Using value of HADOOP_SECURE_DN_USER.
Starting namenodes on [centos7]
centos7: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Starting datanodes
localhost: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
Starting secondary namenodes [centos7]
centos7: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: /hadoop/hadoop-3.2.0/logs/fairscheduler-statedump.log (权限不够)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:133)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
at org.apache.log4j.RollingFileAppender.setFile(RollingFileAppender.java:207)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:307)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:172)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:104)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:842)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768)
at org.apache.log4j.PropertyConfigurator.parseCatsAndRenderers(PropertyConfigurator.java:672)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:516)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.slf4j.impl.Log4jLoggerFactory.<init>(Log4jLoggerFactory.java:66)
at org.slf4j.impl.StaticLoggerBinder.<init>(StaticLoggerBinder.java:72)
at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:45)
at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
at org.apache.hadoop.conf.Configuration.<clinit>(Configuration.java:227)
at org.apache.hadoop.hdfs.tools.GetConf.<clinit>(GetConf.java:131)
二.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@localhost
三.执行jps 没有 nodemanager
原因是：yarn-site.xml 配置出现了问题
在yarn-site.xml添加
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>你的cpu个数</value>
</property>
<property>
<name> yarn.nodemanager.resource.memory-mb </name>
<value> 你的内存</value>
</property>
