yum -y install wget

yum -y install vim* 

centos7安装Java8](https://www.cnblogs.com/tenny-peng/p/11843539.html)

centos7 安装maven

centos 解决 -bash: shasum: command not found

centos这里只要：yum install perl-Digest-SHA

CentOS7如何关闭防火墙

ERROR: but there is no HDFS_NAMENODE_USER defined. Aborting operation. Starting datanodes

https://blog.csdn.net/oschina_41140683/article/details/93976752

Yarn Web页面 8088 端口在Windows浏览器无法访问

https://blog.csdn.net/qq_22310551/article/details/82864966

Centos7下安装netstat

yum install net-tools

Yarn Web页面 8088 端口在Windows浏览器无法访问

https://blog.csdn.net/qq_22310551/article/details/82864966

Linux的netstat查看端口是否开放见解（0.0.0.0与127.0.0.1的区别

https://www.cnblogs.com/lemon-flm/p/7396536.html

Linux7/Centos7 Selinux介绍

https://blog.csdn.net/weixin_41078837/article/details/80571065

---------------------------------------------- 这中间的内容不用考虑了 ----------------------------------------------

外网无法访问8088端口

将文件/root/fluo-uno/install/hadoop-3.2.1/etc/hadoop/yarn-site.xml中的localhost改为192.168.56.100或0.0.0.0

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!--
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License. See accompanying LICENSE file.
-->

<!-- Put site-specific property overrides in this file. -->

<configuration>
  <property>
    <name>yarn.resourcemanager.hostname</name>
    <value>192.168.56.100</value>
  </property>
  <property>
    <name>yarn.nodemanager.local-dirs</name>
    <value>file:///root/fluo-uno/install/data/hadoop/yarn/local</value>
  </property>
  <property>
    <name>yarn.nodemanager.remote-app-log-dir</name>
    <value>/app-logs</value>
  </property>
  <property>
    <name>yarn.nodemanager.log-dirs</name>
    <value>/root/fluo-uno/install/logs/hadoop</value>
  </property>
  <property>
    <name>yarn.nodemanager.aux-services</name>
    <value>mapreduce_shuffle</value>
  </property>
  <property>
    <name>yarn.nodemanager.resource.memory-mb</name>
    <value>8192</value>
  </property>
  <property>
    <name>yarn.nodemanager.resource.cpu-vcores</name>
    <value>8</value>
  </property>
  <property>
    <name>yarn.scheduler.minimum-allocation-mb</name>
    <value>128</value>
  </property>
  <property>
    <name>yarn.nodemanager.vmem-check-enabled</name>
    <value>false</value>
  </property>
  <property>
    <name>yarn.nodemanager.vmem-pmem-ratio</name>
    <value>3.1</value>
  </property>
  <property>
    <name>yarn.nodemanager.delete.debug-delay-sec</name>
    <value>259200</value>
  </property>
  <property>
    <name>yarn.resourcemanager.scheduler.class</name>
    <value>org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler</value>
  </property>

hadoop启动失败

在/root/fluo-uno/install/hadoop-3.2.1/sbin/目录下的start-dsf.sh和stop-dsf.sh中的开头加入

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

在/root/fluo-uno/install/hadoop-3.2.1/sbin/目录下的start-yarn.sh和stop-yarn.sh中的开头加入

YARN_RESOURCEMANAGER_USER=root
HADOOP_SECURE_DN_USER=yarn
YARN_NODEMANAGER_USER=root

---------------------------------------------- 这中间的内容不用考虑了 ----------------------------------------------

在/etc/profile末尾加上

export HDFS_DATANODE_USER=root
export HDFS_NAMENODE_USER=root
export HDFS_SECONDARYNAMENODE_USER=root

export YARN_RESOURCEMANAGER_USER=root
export YARN_NODEMANAGER_USER=root