Hadoop

一、Hadoop集群安装

1. 环境准备

（1） 准备三台机器：hadoop0(192.168.11.10)、hadoop1(192.168.11.11)、hadoop2(192.168.11.12)

 （2）每台机器安装好JAVA环境以及SSH打通（SSH免密登录；关闭防火墙）

2. 下载Hadoop安装包 并解压至相关目录

3. 配置Hadoop相关配置文件

（1）hadoop-env.sh 添加Java环境变量

export JAVA_HOME=/home/vagrant/share/jdk1.8.0_211

（2）core-site.xml

<configuration>
        <property>
                <name>fs.defaultFS</name>
                <value>hdfs://hadoop0:9000</value>
        </property>
        <property>
                <name>io.file.buffer.size</name>
                <value>131072</value>
        </property>
        <property>
                <name>hadoop.tmp.dir</name>
                <value>file:/home/vagrant/share/hadoop-2.9.2/tmp</value>
        </property>
        <property>
                <name>hadoop.proxyuser.root.hosts</name>
                <value>*</value>
        </property>
        <property>
                <name>hadoop.proxyuser.root.groups</name>
                <value>*</value>
        </property>
</configuration>

（3）hdfs-site.xml

<configuration>
        <property>
                <name>dfs.namenode.secondary.http-address</name>
                <value>hadoop0:9001</value>
        </property>
        <property>
                <name>dfs.namenode.name.dir</name>
                <value>file:/home/vagrant/share/hadoop-2.9.2/dfs/name</value>
        </property>
        <property>
                <name>dfs.datanode.data.dir</name>
                <value>file:/home/vagrant/share/hadoop-2.9.2/dfs/data</value>
        </property>
        <property>
                <name>dfs.replication</name>
                <value>2</value>
        </property>
        <property>
                <name>dfs.webhdfs.enabled</name>
                <value>true</value>
        </property>
        <property>
                <name>dfs.permissions</name>
                <value>false</value>
        </property>
        <property>
                <name>dfs.web.ugi</name>
                <value>supergroup</value>
        </property>
</configuration>

（4）mapred-site.xml

<configuration>
        <property>
                <name>mapreduce.framework.name</name>
                <value>yarn</value>
        </property>
        <property>
                <name>mapreduce.jobhistory.address</name>
                <value>hadoop0:10020</value>
        </property>
        <property>
                <name>mapreduce.jobhistory.webapp.address</name>
                <value>hadoop0:19888</value>
        </property>
</configuration>

（5）yarn-site.xml

<configuration>
        <property>
                <name>yarn.nodemanager.aux-services</name>
                <value>mapreduce_shuffle</value>
        </property>
        <property>
                <name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
                <value>org.apache.hadoop.mapred.ShuffleHandler</value>
        </property>
        <property>
                <name>yarn.resourcemanager.address</name>
                <value>hadoop0:8032</value>
        </property>
        <property>
                <name>yarn.resourcemanager.scheduler.address</name>
                <value>hadoop0:8030</value>
        </property>
        <property>
                <name>yarn.resourcemanager.resource-tracker.address</name>
                <value>hadoop0:8031</value>
        </property>
        <property>
                <name>yarn.resourcemanager.admin.address</name>
                <value>hadoop0:8033</value>
        </property>
        <property>
                <name>yarn.resourcemanager.webapp.address</name>
                <value>hadoop0:8088</value>
        </property>
</configuration>

（6）slaves

hadoop1
hadoop2

配置完成以上几个配置文件之后，将其拷贝至另外两台机器。

4.启动Hadoop集群

（1）执行命令格式化name node：./bin/hadoop namenode -format

（2）启动Hadoop：./sbin/start-all.sh

（3）jps查看每个机器进程情况

 - 主节点

   NameNode
   SecondaryNameNode
   ResourceManager

 -从节点

   DataNode
   NodeManager

5. 问题

（1）tmp/nm-local-dir is not a valid path. Path should be with file scheme or without schem

　　解决：使用hadoop默认的tmp目录