1、主机和ip分配如下
     ip地址                  主机名               用途
     192.168.1.112      hadoop1            namenode
     192.168.1.113      hadoop2            datanode
     192.168.1.114      hadoop3            datanode
     192.168.1.115      hadoop4            datanode
2、四台主机主机名修改如下,仅以hadoop1为例
    1) [root@hadoop1 ~]# hostname hadoop1
    2) [root@hadoop1 ~]# vi /etc/sysconfig/network,修改hostname属性值保存
3、四台主机都需要安装jdk
4、关闭防火墙,切换到root用户  执行如下命令 chkconfig iptables off
5、每台主机配置/etc/hosts 增加ip地址解析
   

    hadoop1 192.168.1.112

    hadoop2 192.168.1.113

    hadoop3 192.168.1.114

    hadoop4 192.168.1.115
 5、配置namenode无密码访问datanode
   1) 在namenode机器上,在hadoop用户下执行下面命令
     ssh-keygen -t rsa 
     遇到所有选项回车默认值即可
   2) 导入公钥到本机认证文件
      cat ~/.ssh/id_rsa.pub>>~/.ssh/authorized_keys
   3) 导入公钥到其他datanode节点认证文件
    

    scp ~/.ssh/authorized_keys hadoop@192.168.1.113:/home/hadoop/.ssh/authorized_keys

    scp ~/.ssh/authorized_keys hadoop@192.168.1.114:/home/hadoop/.ssh/authorized_keys

    scp ~/.ssh/authorized_keys hadoop@192.168.1.115:/home/hadoop/.ssh/authorized_keys
    以上过程由于是第一次传输访问,系统会提示输入hadoop用户的密码,输入密码即可。
     4) 验证是否能够无密码登陆到datanode节点
      [hadoop@hadoop1 ~]$ ssh 192.168.1.113 
      如果没有密码提示直接登陆显示如下
        [hadoop@hadoop2 ~]$
       无密码登陆验证通过,访问其他datanode节点类似
6、安装hadoop2.2
   1)解压缩hadoop-2.2.0.tar.gz
       tar -zxf hadoop-2.2.0.tar.gz
       默认解压缩到当前目录下面,这里解压缩/home/hadoop/目录下面
   2) 修改hadoop配置文件
       打开hadoop-2.2.0/etc/hadoop,修改里面的配置文件


      a) hadoop-env.sh,找到里面的JAVA_HOME,修改为实际地址
      b) yarn-env.sh ,同样找到里面的JAVA_HOME,修改为实际路径
      c) slave  这个文件配置所有datanode节点,以便namenode搜索,本例配置如下
         hadoop2
         hadoop3
         hadoop4
      d) core-site.xml
       

    <configuration>

        <property>

            <name>fs.defaultFS</name>

            <value>hdfs://hadoop1:9000</value>

        </property>

        <property>

            <name>io.file.buffer.size</name>

            <value>131072</value>

        </property>

        <property>

            <name>hadoop.tmp.dir</name>

            <value>/home/hadoop/hadoopp-2.2.0/mytmp</value>

            <description>A base for other temporarydirectories.</description>

        </property>

        <property>

            <name>hadoop.proxyuser.root.hosts</name>

            <value>hadoop1</value>

        </property>

        <property>

            <name>hadoop.proxyuser.root.groups</name>

            <value>*</value>

        </property>

    </configuration>

   e) hdfs-site.xml
     

    <configuration>

        <property>

            <name>dfs.namenode.name.dir</name>

            <value>/home/hadoop/name</value>

        <final>true</final>

        </property>

        <property>

            <name>dfs.datanode.data.dir</name>

            <value>/home/hadoop/data</value>

        <final>true</final>

        </property>

        <property>

            <name>dfs.replication</name>

        <value>3</value>

        </property>

        <property>

            <name>dfs.permissions</name>

            <value>false</value>

        </property>

    </configuration>

  f) mapred-site.xml
  

    <configuration>

        <property>

            <name>mapreduce.framework.name</name>

            <value>yarn</value>

        </property>

        <property>

            <name>mapreduce.jobhistory.address</name>

            <value>hadoop1:10020</value>

        </property>

        <property>

            <name>mapreduce.jobhistory.webapp.address</name>

            <value>hadoop1:19888</value>

        </property>

        <property>

                <name>mapreduce.jobhistory.intermediate-done-dir</name>

                <value>/mr-history/tmp</value>

        </property>

        <property>

            <name>mapreduce.jobhistory.done-dir</name>

            <value>/mr-history/done</value>

        </property>

    </configuration>

 g) yarn-site.xml
   

    <configuration>

        <property>

        <name>yarn.resourcemanager.address</name>

        <value>hadoop1:18040</value>

    </property>

    <property>

        <name>yarn.resourcemanager.scheduler.address</name>

        <value>hadoop1:18030</value>

    </property>

    <property>

        <name>yarn.resourcemanager.resource-tracker.address</name>

        <value>hadoop1:18025</value>

    </property>

    <property>

            <name>yarn.resourcemanager.admin.address</name>

            <value>hadoop1:18041</value>

     </property>

     <property>

            <name>yarn.resourcemanager.webapp.address</name>

            <value>hadoop1:8088</value>

    </property>

    <property>

        <name>yarn.nodemanager.local-dirs</name>

        <value>/home/hadoop/mynode/my</value>

    </property>

    <property>

            <name>yarn.nodemanager.log-dirs</name>

            <value>/home/hadoop/mynode/logs</value>

    </property>

    <property>

            <name>yarn.nodemanager.log.retain-seconds</name>

            <value>10800</value>

      </property>

        <property>

            <name>yarn.nodemanager.remote-app-log-dir</name>

            <value>/logs</value>

        </property>

        <property>

            <name>yarn.nodemanager.remote-app-log-dir-suffix</name>

            <value>logs</value>

        </property>

        <property>

            <name>yarn.log-aggregation.retain-seconds</name>

            <value>-1</value>

        </property>

        <property>

            <name>yarn.log-aggregation.retain-check-interval-seconds</name>

            <value>-1</value>

        </property>

        <property>

            <name>yarn.nodemanager.aux-services</name>

            <value>mapreduce_shuffle</value>

        </property>

    </configuration>

  3) 将上述文件配置好后,将hadoop-2.2.0文件复制到其余datanode机器上的相同路径下
    修改/etc/profile文件 设置hadoop环境变量,切换到root用户
     在文件的最后增加如下配置
    

    #hadoop variable settings

    export HADOOP_HOME=/home/hadoop/hadoop-2.2.0

    export HADOOP_COMMON_HOME=$HADOOP_HOME

    export HADOOP_HDFS_HOME=$HADOOP_HOME

    export HADOOP_MAPRED_HOME=$HADOOP_HOME

    export HADOOP_YARN_HOME=$HADOOP_HOME

    export HADOOP_CONF_DIR=$HADOOP_HOME/etc/hadoop

    export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin:$HADOOP_HOME/lib
   

    export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
    export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib"
    增加之后保存
    最后两行特殊说明下,有的文章中遗漏掉这部分配置,最后在启动hadoop2.2时报了下面的错误
  

Hadoop 2.2.0 - warning: You have loaded library /home/hadoop/2.2.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard.


 

<div id="file-hadoop-2-2-0-txt-LC3" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC4" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	Starting namenodes on [Java HotSpot(TM) 64-Bit Server VM warning: You have loaded library /home/hadoop/2.2.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC5" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC6" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	localhost]
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC7" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	sed: -e expression #1, char 6: unknown option to `s'
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC8" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	HotSpot(TM): ssh: Could not resolve hostname HotSpot(TM): Name or service not known
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC9" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	64-Bit: ssh: Could not resolve hostname 64-Bit: Name or service not known
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC10" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	Java: ssh: Could not resolve hostname Java: Name or service not known
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC11" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	Server: ssh: Could not resolve hostname Server: Name or service not known
</span></div><span style="font-size:18px;">

</span><div id="file-hadoop-2-2-0-txt-LC12" class="line" style="word-wrap: break-word;"><span style="font-size:18px;">
	VM: ssh: Could not resolve hostname VM: Name or service not known
</span></div><span style="font-size:18px;">
</span>

 配置完成之后需要重启电脑,所有datanode节点也需要对环境变量增加上面配置,配置完成之后重启电脑
7、hadoop的启动与关闭
   1)hadoop namenode的初始化,只需要第一次的时候初始化,之后就不需要了
       cd /home/hadoop/hadoop-2.2.0/bin
        hdfs namenode -format

   2)启动
       启动:在namenode机器上,进入/home/myhadoop/sbin
       执行脚本start-all.sh
   3) 关闭
       在namenode节点上,进入/home/myhadoop/sbin
      stop-all.sh
8、web接口地址

启动hadoop后,在浏览器中输入地址查看

http://hadoop1:50070

http://hadoop1:8088

http://hadoop1:19888