关于linux:Centos7安装hadoop321

更新工夫：2020-07-29。如果hadoop下载链接生效，则须要自行去hadoop官网找下链接

hadoop3.2.1装置

1.下载

https://mirrors.tuna.tsinghua.edu.cn/apache/hadoop/common/hadoop-3.2.1/hadoop-3.2.1.tar.gz

2.解压

tar -zxvf hadoop-3.2.1.tar.gz

3.重命名

mv hadoop-3.2.1 hadoop

4.增加JAVA_HOME至环境变量
4.1 首先找到JAVA_HOME，执行上面命令，其中有一项是java_home

java -XshowSettings:properties -version

4.2 增加至环境变量

vim /etc/bashrc
# 而后在profile的最上面加一句：
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.252.b09-3.el8_2.x86_64/jre
# 保留退出vim，执行以下命令使环境变量立刻失效
source /etc/bashrc

5.hadoop增加至环境变量

# vim /etc/bashrc文件，退出如下两行
export HADOOP_HOME=/usr/share/hadoop
export PATH=$PATH:$HADOOP_HOME/bin

6.测试hadoop。如果显示版本号，则证实胜利运行。

hadoop version
#Hadoop 3.2.1
#Source code repository https://gitbox.apache.org/repos/asf/hadoop.git -r b3cbbb467e22ea829b3808f4b7b01d07e0bf3842
#Compiled by rohithsharmaks on 2019-09-10T15:56Z
#Compiled with protoc 2.5.0
#From source with checksum 776eaf9eee9c0ffc370bcbc1888737
#This command was run using /usr/share/hadoop/share/hadoop/common/hadoop-common-3.2.1.jar

hdfs配置（伪分布式）

1.创立hadoop用户（专门为hadoop筹备的用户），以下操作在root用户下执行

#创立hadoop用户
useradd -m hadoop -s /bin/bash
#批改明码
passwd hadoop
#切换至hadoop用户
su hadoop
#设置ssh免密登录（ssh免密登录本身，如果不设置，启动DFS会报错）
ssh-keygen -t rsa
#将本人生成的公钥退出本人的受权，这样本人就能够免密登录本人
cd ~/.ssh
cat id_rsa.pub >> authorized_keys
chmod 600 authorized_keys  # 避免其余用户看到

2.配置core-site.xml

vim /usr/share/hadoop/etc/hadoop/core-site.xml
#退出如下配置（其中应用hadoop代替了ip地址，后续须要在hosts文件内退出对应的ip）
#（存文件的门路最好写到hadoop用户的家目录下，防止权限问题）
<configuration>
        <property>
             <name>hadoop.tmp.dir</name>
             <value>file:/home/hadoop/tmp</value>
             <description>Abase for other temporary directories.</description>
        </property>
        <property>
             <name>fs.defaultFS</name>
             <value>hdfs://hadoop:9000</value>
        </property>
</configuration>

3.配置hdfs-site.xml

vim /usr/share/hadoop/etc/hadoop/hdfs-site.xml
#退出如下配置
<configuration>
        <property>
             <name>dfs.replication</name>
             <value>1</value>
        </property>
        <property>
             <name>dfs.namenode.name.dir</name>
             <value>file:/home/hadoop/tmp/dfs/name</value>
        </property>
        <property>
             <name>dfs.datanode.data.dir</name>
             <value>file:/home/hadoop/tmp/dfs/data</value>
        </property>
</configuration>

4.配置yarn-site,xml

vim /usr/share/hadoop/etc/hadoop/yarn-site.xml
#退出如下配置
<configuration>
     <property>
          <name>yarn.nodemanager.aux-services</name>
          <value>mapreduce_shuffle</value>
     </property>
     <property>
           <name>yarn.resourcemanager.hostname</name>
           <value>hadoop</value>
     </property>
</configuration>

5.配置mapred-site.xml

vim /usr/share/hadoop/etc/hadoop/mapred-site.xml
#退出如下配置
<configuration>
　  <property>  
　　    <name>mapreduce.framework.name</name>  
　　    <value>yarn</value>  
　 </property>  
</configuration>

6.批改hosts文件

su root
vim /etc/hosts
#最上面退出
0.0.0.0 hadoop

7.格式化HDFS零碎

su hadoop
/usr/share/hadoop/bin/hdfs namenode -format

8.启动hadoop-DFS

/usr/share/hadoop/sbin/start-dfs.sh
#hadoop: namenode is running as process 25242.  Stop it first.
#Starting datanodes
#localhost: datanode is running as process 25402.  Stop it first.
#Starting secondary namenodes [hadoop]
#hadoop: secondarynamenode is running as process 25607.  Stop it first.

/usr/share/hadoop/sbin/start-yarn.sh
#Starting resourcemanager
#Starting nodemanagers

9.浏览器拜访web页面（Centos留神敞开防火墙）

http://<hadoop ip>:9870 #dfs
http://<hadoop ip>:8088 #yarn