安装

brew install hadoop

Linux用户可以直接下载tar包，解压运行
https://apache.claz.org/hadoop/common/hadoop-3.3.0/hadoop-3.3.0.tar.gz

配置本地登陆

cat ~/.ssh/id_rsa.pub > ~/.ssh/authorized_keys

**系统配置（仅Mac需要）
系统->共享里的：

配置hadoop四个文件

hadoop-env.sh

添加java home

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home

mapred-site.xml

添加

<configuration>
    <property>
        <name>mapred.job.tracker</name>
        <value>localhost:9010</value>
    </property>
</configuration>

hdfs-site.xml

添加

<configuration>
    <property>
        <name>dfs.replication</name>
        <value>1</value>
    </property>
</configuration>

yarn-site.xml（修改告警阀值，默认95%，非必须）

添加

<property>
	<name>yarn.nodemanager.disk-health-checker.max-disk-utilization-per-disk-percentage</name>
	<value>98.0</value>
</property>

core-site.xml

添加

<configuration>
    <property>
        <name>hadoop.tmp.dir</name>
	<value>/usr/local/Cellar/hadoop/3.3.0/data/tmp</value>
        <description>A base for other temporary directories.</description>
    </property>
    <property>
       <name>fs.defaultFS</name>
       <value>hdfs://localhost:9000</value>
    </property>
</configuration>

初始化namenode

hadoop namenode -format

启动

/usr/local/Cellar/hadoop/3.3.0/sbin/start-all.sh

查看(node,yarn)
http://localhost:8042/node
http://localhost:9870/

应用

创建目录和文件

hadoop fs -mkdir -p /input
echo 'hello word' > word.txt 
hadoop fs -put word.txt /input/

使用hadoop 示例：
统计文件中word的数量

hadoop jar /usr/local/Cellar/hadoop/3.3.0/libexec/share/hadoop/mapreduce/sources/hadoop-mapreduce-examples-3.3.0-sources.jar org.apache.hadoop.examples.WordCount /input/word.txt /input/out/word-out