hadoop有三种运行方式：单价模式，伪分布式，完全分布模式
在此介绍下完全分布模式。
安装前应先将VMware和linux系统安装好（我安装的VMware 9.0 和redhat 5），
安装VMware Tools，调通网络，桥接，NAT都行，我用是桥接方式。
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步骤：
1、配置hosts文件
2、建立hadoop运行账号
3、配置ssh免密码连入
4、下载并解压hadoop安装包
5、配置namenode，修改site文件
6、配置hadoop-env.sh文件
7、配置masters和slaves文件
8、向各个节点复制hadoop
9、格式化mamenode
10、启动hadoop
11、使用jps检验各个后台进程是否成功启动
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1、配置hosts文件，修改所有节点的/etc/hosts,使彼此之间都能把主机名解析为IP
[root@red1 ~]# sudo gedit /etc/hosts # Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 localhost.localdomain localhost ::1 localhost2.localdomain2 localhost2 172.21.42.84 red1 172.21.42.82 red2
2、在所有的节点上都建立运行hadoop的账号
[root@red1 ~]# useradd hadoop [root@red1 ~]# passwd hadoop
3、ssh配置，注意要以hadoop用户的主目录下进行操作，每个节点相同
[hadoop@red1 ~]$ 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'. 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: 9b:82:ea:58:b4:e0:35:d7:ff:19:66:a6:ef:ae:0e:d2 hadoop@red1 [hadoop@red1 /]$ cd /home/hadoop/.ssh/ [hadoop@red1 .ssh]$ ls id_rsa id_rsa.pub known_hosts [hadoop@red1 ~]$ cp id_rsa.pub authorized_keys
同理：在其他节点上进行相应操作。
分发ssh公钥，把各个节点的authorized_keys的内容互相拷贝加入到对方的此文件中，然后可以实现免密码彼此ssh连入
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAmzXjSVazkfYs6WDxSnopXf41mKDMKj D4m7ZwH9+peZVQAWIzGAlkVn6Osn/dSZAKhdPqf8dTQfgtw8BkgapqCq3dWCImeEOl T6Hw452+AH55BiDnzleuOLueh+itq639DCFty8zMSj0H14GVc0KMfsQxnJqsCfF7EY pwVWzmFI8bbMeoynQA1m5QIJEJC8AsLKy8/MZhy9GaGKTv/BkDwpkbF1LsLew7Mg35 /ddeX7z8Fsx7nS2rko8/rAxRO47JEFVw2VXVeWfdPPXNVbTXppu0StV+Pdaffell6D jKizHf8aX87MRHFK+8DiTBD5+BsZsmw9ynbjJasxMl05Kxnw== hadoop@red1 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAn86HahOIgUA7FeIwgfvJx8IdvRFuCy x8MEdFqhFThLBE49RoG0wkmc06j2uSb/Kq9xTrIQrev0dP0i9QPUCBn8DaQ80AylE8 uqOPivXqFLd9Qni/mAqASaOkHM5SWU8fPJAZIljq5nJ+zSUXC381isqwYkX63lPJZu traCglEy6yJoqfvvR5TKrAm9nLNCl3SYRoH/nT1+Vt+ywVaaFkTzvZUbiAs54krz3E on8n8tFAJvlMAvZdmoy+s/bBUTTsR4SPwG7teRXTrJBD2zHAJnzVMu8AJe3TipyXBh PlT5Gfu8RgfhTMx/S2rCIfezqi4pc5vFKY5u0UJdbF7cTC6w== hadoop@red2
4、下载hadoop压缩包并解压
[hadoop@red1 ~]$ tar -zxvf hadoop-0.20.2.tar.gz /home/hadoop/
5、修改配置文件
(1) 修改core-site.xml文件
[hadoop@red1 ~]# cd /home/hadoop/hadoop-0.20.2/conf/
[hadoop@red1 conf]# sudo gedit core-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://red1:9000</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/home/hadoop/hadoop-0.20.2/tmp</value>
</property>
</configuration>
(2) 修改mapred-site.xml
[hadoop@red1 conf]# sudo gedit mapred-site.xml <?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>mapred.job.tracker</name> <value>red1:9001</value> </property> </configuration>
(3) 修改 hdfs-site.xml 文件
[hadoop@red1 conf]# sudo gedit hdfs-site.xml <?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>dfs.name.dir</name> <value>/home/hadoop/hdfs/name</value> </property> <property> <name>dfs.data.dir</name> <value>/home/hadoop/hdfs/data</value> </property> <property> <name>dfs.replication</name> <value>1</value> </property> </configuration>
6、配置hadoop-env.sh文件
在hadoop-env.sh文件中配置jdk的环境变量
# The java implementation to use. Required. # export JAVA_HOME=/usr/lib/j2sdk1.5-sun export JAVA_HOME=/usr/java/jdk1.6.0_03
7、配置masters和slaves文件
masters文件中添加 red1
[hadoop@red1 conf]$ sudo gedit masters
slaves文件中添加 red2
[hadoop@red1 conf]$ sudo gedit slaves
8、向各个节点复制hadoop
[hadoop@red1 conf]$ scp -r /home/hadoop/hadoop-0.20.2 red2:/home/hadoop
9、格式化mamenode
[hadoop@red1 hadoop-0.20.2]$ bin/hadoop namenode -format
14/01/21 16:35:09 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = red1/172.21.42.84
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 0.20.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20 -r 911707; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010
************************************************************/
14/01/21 16:35:09 INFO namenode.FSNamesystem: fsOwner=hadoop,hadoop
14/01/21 16:35:09 INFO namenode.FSNamesystem: supergroup=supergroup
14/01/21 16:35:09 INFO namenode.FSNamesystem: isPermissionEnabled=true
14/01/21 16:35:09 INFO common.Storage: Image file of size 96 saved in 0 seconds.
14/01/21 16:35:09 INFO common.Storage: Storage directory .../hadoop-hadoop/dfs/name has been successfully formatted.
14/01/21 16:35:09 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at red1/172.21.42.84
************************************************************/
没有waring和error，出现has been successfully，格式成功。
10、启动hadoop
[hadoop@red1 ~]$ start-all.sh starting namenode, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-namenode-red1.out red2: starting datanode, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-datanode-red2.out red1: starting secondarynamenode, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-secondarynamenode-red1.out starting jobtracker, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-jobtracker-red1.out red2: starting tasktracker, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-tasktracker-red2.out
11、使用jps检验各个后台进程是否成功启动
namenode节点
[hadoop@red1 ~]# /usr/java/jdk1.6.0_03/bin/jps 27561 Jps 7377 NameNode 7606 JobTracker 7523 SecondaryNameNode
datanode节点
[hadoop@red2 ~]$ /usr/java/jdk1.6.0_03/bin/jps 14745 Jps 6658 TaskTracker 6577 DataNode
成功。