[Hadoop]完全分布式集群安装过程详解
1. 用Vmware Workstation创建4个
虚拟机，每个虚拟机都装上Centos（版本：CentOS-6.3-x86_64），示意图如下：
2. 在所有结点上修改/etc/hosts，使彼此之间都能够用机器名解析IP
192.168.231.131 node01
192.168.231.132 node02
192.168.231.133 node03
192.168.231.134 node04
3. 在所有结点上安装JDK
首先，把jdk安装包（jdk-6u38-linux-x64.bin）放到/usr/java
增加可执行权限：
[root@localhost java]# chmod a+xjdk-6u38-linux-x64.bin
[root@localhost java]# ls -lrt
total 70376
-rwxr-xr-x. 1 root root 72058033 Jan 2907:21 jdk-6u38-linux-x64.bin
下面开始安装JDK：
[root@localhost java]# ./jdk-6u38-linux-x64.bin
更改/etc/profile，添加以下几行：
JAVA_HOME=/usr/java/jdk1.6.0_38
JRE_HOME=/usr/java/jdk1.6.0_38/jre/
CLASSPATH=.:$JAVA_HOME/lib:$JAVA_HOME/lib/tools.jar
PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
测试是否安装成功：
[root@localhost java]# source /etc/profile
[root@localhost java]# java -version
java version "1.6.0_38"
Java(TM) SE Runtime Environment (build1.6.0_38-b05)
Java HotSpot(TM) 64-Bit Server VM (build20.13-b02, mixed mode)
4. 添加Hadoop用户
[root@node02 ~]# useradd hadoop -g root
[root@node02 ~]# passwd hadoop
Changing password for user hadoop.
New password:
BAD PASSWORD: it is too short
BAD PASSWORD: is too simple
Retype new password:
passwd: all authentication tokens updatedsuccessfully.
5. ssh 配置
注意：下面开始以hadoop用户操作
[hadoop@node01 ~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key(/home/hadoop/.ssh/id_rsa):
Created directory '/home/hadoop/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/hadoop/.ssh/id_rsa.
Your public key has been saved in/home/hadoop/.ssh/id_rsa.pub.
The key fingerprint is:
1d:03:8c:2f:99:95:98:c1:3d:8b:21:61:3e:a9:cb:bfhadoop@node01
The key's randomart image is:
+--[ RSA 2048]----+
| oo.B.. |
| o..* *. |
| +. B oo |
| ..= o. o |
| . .S . |
| . . |
| o |
| . |
| E. |
+-----------------+
[hadoop@node01 ~]$ cd .ssh
[hadoop@node01 .ssh]$ cp id_rsa.pubauthorized_keys
把所有结点的authorized_keys的内容都互相拷贝，这样就可以免密码ssh连入。
6. 安装Hadoop
[hadoop@node01 ~]$ ls
hadoop-0.20.2 hadoop-0.20.2.tar.gz
[hadoop@node01 ~]$ tar xzvf./hadoop-0.20.2.tar.gz
7. 配置namenode (node01)
修改hadoop-env.sh
[hadoop@node01 conf]$ vi hadoop-env.sh
# The java implementation to use. Required.
export JAVA_HOME=/usr/java/jdk1.6.0_38
修改core-site.xml
[hadoop@node01 conf]$ vi core-site.xml
fs.default.name
hdfs://192.168.231.131:9000
修改hdfs-site.xml
[hadoop@node01 conf]$ vi hdfs-site.xml
dfs.data.dir
/home/hadoop/hadoop-0.20.2/data
dfs.replication
3
修改mapred-site.xml
[hadoop@node01 conf]$ vi mapred-site.xml
mapred.job.tracker
192.168.231.131:9001
修改masters和slaves文件，记录集群中各个结点
[hadoop@node01 conf]$ vi masters
node01
[hadoop@node01 conf]$ vi slaves
node02
node03
node04
向其它3个结点复制hadoop
[hadoop@node01 ~]$ scp -r ./hadoop-0.20.2node02:/home/hadoop
[hadoop@node01 ~]$ scp -r ./hadoop-0.20.2node03:/home/hadoop
[hadoop@node01 ~]$ scp -r ./hadoop-0.20.2node04:/home
