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Hadoop 分布式环境搭建

Hadoop 分布式环境搭建

一、前期环境

  • 安装概览
IP Host Name Software Node
192.168.23.128 ae01 JDK 1.7 NameNode, SecondaryNameNode, DataNode, JobTracker, TaskTracker
192.168.23.129 ae02 JDK 1.7 DataNode, TaskTracker
192.168.23.130 ae03 JDK 1.7 DataNode, TaskTracker
    若使用虚拟机安装,可以安装samba, smbfs方面对于文件的控制。
  • 系统环境: ubuntu-12.04.2-server-amd64
  • 安装目录: /usr/local/ae
  • JDK 安装目录: export JAVA_HOME=/usr/local/ae/jdk1.7.0_51
  • Hadoop版本: hadoop-1.2.1

二、服务器间无密码登录

进入每台服务器,分别安装SSH,并生成ssh-key。下面安装步骤只讲解在ae01安装SSH和生成SSH-KEY,ae02、ae03重复此步骤。

  • 安装SSH
    user@ae01:~$ sudo apt-get install openssh-server
  • 生成SSH-KEY
    user@ae01:~# ssh-keygen -t rsa -P ""
    Generating public/private rsa key pair.
    Enter file in which to save the key (/root/.ssh/id_rsa):
    Created directory /root/.ssh.
    Your identification has been saved in /root/.ssh/id_rsa.
    Your public key has been saved in /root/.ssh/id_rsa.pub.
    The key fingerprint is:
    64:3d:a4:70:94:c4:33:64:6b:6b:1c:7c:e9:8f:15:93 user@ae01
    The keys randomart image is:
    +--[ RSA 2048]----+
    |      .=*..      |
    |       === . .   |
    |        Oo= E    |
    |       = = . o   |
    |        S . .    |
    |       .   +     |
    |          . .    |
    |                 |
    |                 |
    +-----------------+
  • 配置无密码SSH登录
    如果你希望服务器a1不需要密码就能SSH登录服务器a2,你需要将a1生成的公共密码添加到a2的~/.ssh/authorized_keys文件.
    此次安装中,ae01是NameNode,需要无密码登录到DataNode(ae02,ae03)的服务器,所以我们需要分别将ae01生成的公钥,添加到ae02,ae03的authorized_keys文件。
    修改ae01的公钥名字为id_rsa_ae01.pub。
    user@ae01:~/.ssh$ sudo cp id_rsa.pub id_rsa_ae01.pub

    复制id_rsa_ae01.pub到服务器ae02

    user@ae01:~/.ssh$ scp ./id_rsa_ae01.pub user@192.168.23.129:~/.ssh/

    登录到ae02,将id_rsa_ae01.pub 添加到authorized_keys

    user@ae02:~/.ssh$ cat id_rsa_ae01.pub >> authorized_keys

    重新登录到ae01,并尝试无密码方面ae02

    user@ae01:~/.ssh$ ssh ae02
    Welcome to Ubuntu 12.04.2 LTS (GNU/Linux 3.5.0-23-generic x86_64)
    
     * Documentation:  https://help.ubuntu.com/
    
      System information as of Thu Jun 12 12:21:45 CST 2014
    
      System load:  0.0                Processes:           86
      Usage of /:   10.3% of 18.45GB   Users logged in:     1
      Memory usage: 35%                IP address for eth0: 192.168.23.129
      Swap usage:   0%
    
      Graph this data and manage this system at https://landscape.canonical.com/
    
    122 packages can be updated.
    69 updates are security updates.
    
    Last login: Tue Jun 10 20:06:57 2014 from 192.168.23.128

    对以上机器都进行如上操作,确保两两之间可以实现无密码ssh.

三、安装Hadoop

  • 修改host文件,添加3台服务器的host
    user@ae01:/usr/local/ae$ sudo vim /etc/hosts
    127.0.0.1         localhost
    192.168.23.128    ae01
    192.168.23.129    ae02
    192.168.23.129    ae03
  • 解压Hadoop
    将hadoop-1.2.1.tar.gz 复制到 /usr/local/ae,解压
    user@ae01:/usr/local/ae$ sudo tar -zxvf hadoop-1.2.1.tar.gz
  • 添加Hadoop环境变量
    export HADOOP_HOME=/usr/local/ae/hadoop-1.2.1
    export HADOOP_HOME_WARN_SUPPRESS=1
    export PATH=$PATH:$HADOOP_HOME/bin
  • 配置Hadoop
    core-site.xml是全局配置,hdfs-site.xml和mapred-site.xml分别是hdfs和mapred的局部配置

    修改$HADOOP_HOME/conf/hadoop-env.sh 添加JAVA_HOME

    export JAVA_HOME=/usr/local/ae/jdk1.7.0_51

    修改$HADOOP_HOME/conf/core-site.xml 加入以下文件到<configuration>节点

    <property>
            <name>hadoop.tmp.dir</name>
            <value>/usr/local/ae/storage/hadoop/temp</value>
            <description>A base for other temporary directories.</description>
    </property>
    
    <property>
            <name>fs.default.name</name>
            <value>hdfs://ae01:9000</value>
            <description>
    The name of the default file system.  A URI whose scheme and authority determine the FileSystem implementation.  The uri‘s scheme determines the config property (fs.SCHEME.impl) naming the FileSystem implementation class.  The uri‘s authority is used to
        determine the host, port, etc. for a filesystem.
            </description>
    </property>
    <property>
            <name>fs.checkpoint.period</name>
            <value>3600</value>
            <description>
    The number of seconds between two periodic checkpoints.
            </description>
    </property>
    
    <property>
            <name>fs.checkpoint.size</name>
            <value>67108864</value>
            <description>
    The size of the current edit log (in bytes) that triggers a periodic checkpoint even if the fs.checkpoint.period hasn‘t expired.
            </description>
    </property>

    修改$HADOOP_HOME/conf/hdfs-site.xml 加入以下文件到<configuration>节点

    <property>
            <name>dfs.name.dir</name>
            <value>/usr/local/ae/storage/hadoop/name</value>
            <description>
    Determines where on the local filesystem the DFS name node should store the name table(fsimage).  If this is a comma-delimited list of directories then the name table is replicated in all of the directories, for redundancy.
            </description>
    </property>
    
    <property>
            <name>dfs.data.dir</name>
            <value>/usr/local/ae/storage/hadoop/data</value>
            <description>]
    Determines where on the local filesystem the DFS name node should store the name table(fsimage).  If this is a comma-delimited list of directories then the name table is replicated in all of the directories, for redundancy.
            </description>
    </property>
    
    <property>
            <name>dfs.http.address</name>
            <value>ae01:50070</value>
            <description>
    The address and the base port where the dfs namenode web ui will listen on. If the port is 0 then the server will start on a free port.
            </description>
    </property>
    
    <property>
            <name>dfs.permissions</name>
            <value>false</value>
            <description>
    If "true", enable permission checking in HDFS. If "false", permission checking is turned off,
    but all other behavior is unchanged. Switching from one parameter value to the other does not change the mode, owner or group of files or directories.
            </description>
    </property>
    
    <property>
            <name>dfs.replication</name>
            <value>1</value>
            <description>Default block replication. The actual number of replications can be specified when the file is created. The default is used if replication is not specified in create time.
            </description>
    </property>

    修改$HADOOP_HOME/conf/hdfs-site.xml 加入以下文件到<configuration>节点

    <property>
            <name>mapred.job.tracker</name>
            <value>ae01:9001</value>
            <description>
    The host and port that the MapReduce job tracker runs  at.  If "local", then jobs are run in-process as a single map and reduce task.
            </description>
       </property> 

    修改$HADOOP_HOME/conf/masters

    ae01

    修改$HADOOP_HOME/conf/slaves

    ae01
    ae02
    ae03

    在上述配置中:
    fs.default.name的值hdfs://ae23:9000 用来决定NameNode
    mapred.job.tracker的值ae23:9001 用来决定JobTracker
    masters文件的值决定SecondaryNameNode
    slaves文件的值决定DataNode和TaskTracker

    创建文件目录/usr/local/ae/storage/hadoop, 并赋予hadoop 文件夹足够的权限

    user@ae01: ~$ /usr/local/ae$ sudo chmod 777 ./storage/hadoop/

   将配置好的Hadoop复制到ae02和ae03,并在ae02和ae03上创建文件目录/usr/local/ae/storage/hadoop

  • 初始化和启动Hadoop

    登录ae01,初始化

    user@ae01:~$ hadoop namenode -format

    启动Hadoop

    user@ae01:~$ start-all.sh

    使用jps查看java进程
    ae01

    user@ae01:/usr/local/ae$ jps
    26239 JobTracker
    26158 SecondaryNameNode
    36052 Jps
    26468 TaskTracker
    25687 NameNode
    25926 DataNode

    ae02

    user@ae02:~$ jps
    25021 Jps
    18999 TaskTracker
    18791 DataNode

    ae03

    user@ae03:~$ jps
    3901 DataNode
    9485 Jps
    4106 TaskTracker