hadoop伪分布式的搭建

在安装hadoop之前确保已经安装好jdk，hadoop安装包路径Hadoop家族，此文章以hadoop-2.4.1为例，完成伪分布式集群的搭建

1、上传hadoop-2.4.1到Linux上，并解压

[hadoop01@hadoop01 hadoop]$ tar -zxvf hadoop-2.4.1.tar.gz 

2、进入hadoop-2.4.1的配置文件路径中

[hadoop01@hadoop01 ~]$ cd hadoop-2.4.1/etc/hadoop/

3、修改Hadoop的配置文件，文件包含 hadoop-env.sh、 core-site.xml、 hdfs-site.xml、mapred-site.xml.template、yarn-site.xml、slaves

-----> 修改hadoop-env.sh <-----

[hadoop01@hadoop01 hadoop]$ vim hadoop-env.sh 
export JAVA_HOME=/home/hadoop01/jdk1.7.0_67 #将此处修改为你的jdk路径

-----> 修改core-site.xml<-----

[hadoop01@hadoop01 hadoop]$ vim core-site.xml 

添加以下内容

    fs.defaultFS
    hdfs://192.168.110.110:9000 ## 此处修改为你的ip，端口号为9000



    hadoop.tmp.dir
    /home/hadoop01/hadoop-2.4.1/tmp ## 此处修改为你保存文件的路径

-----> 修改hdfs-site.xml<-----

[hadoop01@hadoop01 hadoop]$ vim hdfs-site.xml

添加以下内容

        dfs.replication
        1  ## 我这里是单机版 所以设为1



	dfs.secondary.http.address
	192.168.110.110:50090## 改成你的ip，端口号为50090

-----> 修改mapred-site.xml.template<-----

[hadoop01@hadoop01 hadoop]$ mv mapred-site.xml.template mapred-site.xml
[hadoop01@hadoop01 hadoop]$ vim mapred-site.xml

 添加以下内容

        mapreduce.framework.name
        yarn

-----> 修改yarn-site.xml<-----

[hadoop01@hadoop01 hadoop]$ vim yarn-site.xml

添加以下内容

        yarn.resourcemanager.hostname
        localhost	## 你的主机名



        yarn.nodemanager.aux-services
        mapreduce_shuffle

-----> 修改slaves(这里可以不改)<-----

[hadoop01@hadoop01 hadoop]$ vim slaves 
localhost	## datanode节点ip

4、将hadoop添加到环境变量

[hadoop01@hadoop01 etc]# vim /etc/profile
############HADOOP_HOME#############
export HADOOP_HOME=/home/hadoop01/hadoop-2.4.1
export PATH=$PATH:$JAVA_HOME/bin:$HADOOP_HOME/bin:$HADOOP_HOME/sbin

5、刷新配置文件、查询hadoop版本

[hadoop01@hadoop01 hadoop]$ source /etc/profile
[hadoop01@hadoop01 hadoop]$ hadoop version
Hadoop 2.4.1
Subversion http://svn.apache.org/repos/asf/hadoop/common -r 1604318
Compiled by jenkins on 2014-06-21T05:43Z
Compiled with protoc 2.5.0
From source with checksum bb7ac0a3c73dc131f4844b873c74b630
This command was run using /home/hadoop01/hadoop-2.4.1/share/hadoop/common/hadoop-common-2.4.1.jar

6、格式化namenode

[hadoop01@hadoop01 hadoop]$ hdfs namenode -format

最后有一行输出如下，则证明格式化成功

17/01/19 14:00:53 INFO common.Storage: Storage directory /home/hadoop01/hadoop-2.4.1/tmp/dfs/name has been successfully formatted

7、进入hadoop目录下的sbin下，启动hadoop，可以使用./start-all.sh启动，但是建议先启动HDFS再启动YARN

---->启动HDFS

[hadoop01@hadoop01 sbin]$ ./start-dfs.sh 

查看HDFS启动情况,出现以下服务名称，则证明启动成功

[hadoop01@hadoop01 sbin]$ jps
25550 DataNode
25695 SecondaryNameNode
25807 Jps
25435 NameNode

----->启动YARN

[hadoop01@hadoop01 sbin]$ ./start-yarn.sh

查看YARN启动，出现ResourceManager和NodeManager服务，则证明YARN启动成功

[hadoop01@hadoop01 sbin]$ jps
25550 DataNode
25695 SecondaryNameNode
26266 Jps
25861 ResourceManager
26146 NodeManager
25435 NameNode

8、配置ssh免密登录
输入以下命令，出现提示按回车即可

[hadoop01@hadoop01 sbin]$ cd ~
[hadoop01@hadoop01 ~]$ ssh-keygen

执行完这个命令后，会生成两个文件id_rsa（私钥）、id_rsa.pub（公钥）将公钥拷贝到要免密登陆的目标机器上

[hadoop01@hadoop01 ~]$ ssh-copy-id localhost

检查ssh免密登录是否成功，不需要输入密码，则表示成功

[hadoop01@hadoop01 ~]$ ssh localhost