Hadoop单机安装配置过程：

1. 首先安装JDK，必须是sun公司的jdk，最好1.6版本以上。

最后java –version 查看成功与否。

注意配置/etc/profile文件，在其后面加上下面几句：

export JAVA_HOME=/usr/local/jdk1.6.0_17
export PATH=$JAVA_HOME/bin:$JAVA_HOME/jre:$PATH
export CLASSPATH=$JAVA_HOME/lib:$JAVA_HOME/lib/tools.jar

2. 安装ssh，免密码登陆。

apt-get install openssh-server 安装ssh

建立 SSH KEY：

$ ssh-keygen -t rsa -P "" （注意不要多加空格或缺少空格）

中途需要安装者选择保存密钥的文件，按回车使用默认的文件就可以了：

Enter file in which to save the key (/root/.ssh/id_rsa):（按回车）

启用SSH KEY:

$ cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys

/etc/init.d/ssh reload

reload ssh

ssh localhost

3. 安装配置单机hadoop

1)解压到/opt/hadoop

Java代码

$ tar zxvf hadoop-0.20.2.tar.gz

$ sudo mv hadoop-0.20.2 /opt/

$ sudo chown -R hadoop:hadoop /opt/hadoop-0.20.2

$ sudo ln -sf /opt/hadoop-0.20.2 /opt/hadoop

4. 配置 hadoop-env.sh
1）在hadoop/conf 里面hadoop-env.sh增加

Java代码

export JAVA_HOME=/usr/jdk1.6.0.18

export HADOOP_HOME=/opt/hadoop

export PATH=$PATH:/opt/hadoop/bin

5.配置文件
1)編輯 /opt/hadoop/conf/core-site.xml

Java代码

<configuration>

<property>

<name>fs.default.name</name>

<value>hdfs://localhost:9000</value>

</property>

<property>

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

<value>/tmp/hadoop/hadoop-${user.name}</value>

</property>

</configuration>

2)編輯 /opt/hadoop/conf/hdfs-site.xml

Java代码

<configuration>

<property>

<name>dfs.replication</name>

<value>1</value>

</property>

</configuration>

3)編輯 /opt/hadoop/conf/mapred-site.xml

Java代码

<configuration>

<property>

<name>mapred.job.tracker</name>

<value>localhost:9001</value>

</property>

</configuration>

6.格式化hdfs

Java代码

$ cd /opt/hadoop

$ source conf/hadoop-env.sh

$ hadoop namenode -format

提示信息一大堆...

7. 启动hadoop

Java代码

$ sudo ./start-all.sh //在hadoop/bin下执行

8.完成后的测试

Java代码
http://localhost:50030/ - Hadoop 管理接口

启动
[hadoop@hadoop00 ~]$ ~/hadoop-0.21.0/bin/start-all.sh
This script is Deprecated. Instead use start-dfs.sh and start-mapred.sh
starting namenode, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-namenode-hadoop00.out
192.168.91.11: starting datanode, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-datanode-hadoop01.out
192.168.91.12: starting datanode, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-datanode-hadoop02.out
192.168.91.10: starting secondarynamenode, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-secondarynamenode-hadoop00.out
starting jobtracker, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-jobtracker-hadoop00.out
192.168.91.12: starting tasktracker, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-tasktracker-hadoop02.out
192.168.91.11: starting tasktracker, logging to /home/hadoop/hadoop-0.21.0/bin/../logs/hadoop-hadoop-tasktracker-hadoop01.out

2.停止
[hadoop@hadoop00 ~]$ ~/hadoop-0.21.0/bin/stop-all.sh
This script is Deprecated. Instead use stop-dfs.sh and stop-mapred.sh
stopping namenode
192.168.91.12: stopping datanode
192.168.91.11: stopping datanode
192.168.91.10: stopping secondarynamenode
stopping jobtracker
192.168.91.11: stopping tasktracker
192.168.91.12: stopping tasktracker

初始配置HDFS
1、 格式化HDFS文件系统
[hadoop@hadoop00 ~]$ hadoop namenode -format

2、 查看HDFS
[hadoop@hadoop00 ~]$ hadoop fs -ls /
11/09/24 07:49:55 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000
11/09/24 07:49:56 WARN conf.Configuration: mapred.task.id is deprecated. Instead, use mapreduce.task.attempt.id
Found 4 items
drwxr-xr-x - hadoop supergroup 0 2011-09-22 08:05 /home
drwxr-xr-x - hadoop supergroup 0 2011-09-22 11:29 /jobtracker
drwxr-xr-x - hadoop supergroup 0 2011-09-22 11:23 /user

3、 通过WEB查看hadoop
查看集群状态 http://192.168.91.10:50070/dfshealth.jsp

查看JOB状态 http://192.168.91.10:50030/jobtracker.jsp

运行hadoop的example-wordcount
Wordcount程序是一个简单的计算输入文件中每个单词出现的次数，并输出到指定的目录下。该程序是官方的例子，在hadoop-0.21.0安装目录下的：hadoop-mapred-examples-0.21.0.jar

在hdfs上建立程序的输入目录和文件，同时建立程序的输出目录.
[hadoop@hadoop00 ~]$ mkdir input
[hadoop@hadoop00 ~]$ cat a a a a a b b b c c c c c c c c c 1 1 1 > input/file
[hadoop@hadoop00 ~]$ hadoop fs –mkdir /wordcount
[hadoop@hadoop00 ~]$ hadoop fs –put input /wordcount

[hadoop@hadoop00 ~]$ hadoop jar hadoop-0.21.0/hadoop-mapred-examples-0.21.0.jar wordcount /wordcount/input /wordcount/output
11/09/24 08:11:25 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000
11/09/24 08:11:26 WARN conf.Configuration: mapred.task.id is deprecated. Instead, use mapreduce.task.attempt.id
11/09/24 08:11:26 WARN mapreduce.JobSubmitter: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
11/09/24 08:11:26 INFO input.FileInputFormat: Total input paths to process : 2
11/09/24 08:11:26 WARN conf.Configuration: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps
11/09/24 08:11:26 INFO mapreduce.JobSubmitter: number of splits:2
11/09/24 08:11:27 INFO mapreduce.JobSubmitter: adding the following namenodes' delegation tokens:null
11/09/24 08:11:27 INFO mapreduce.Job: Running job: job_201109240745_0002
11/09/24 08:11:28 INFO mapreduce.Job: map 0% reduce 0%
11/09/24 08:11:44 INFO mapreduce.Job: map 50% reduce 0%
11/09/24 08:11:50 INFO mapreduce.Job: map 100% reduce 0%
11/09/24 08:11:57 INFO mapreduce.Job: map 100% reduce 100%
11/09/24 08:11:59 INFO mapreduce.Job: Job complete: job_201109240745_0002
11/09/24 08:11:59 INFO mapreduce.Job: Counters: 34
……

[hadoop@hadoop00 ~]$ hadoop fs -cat /wordcount/output/part-r-00000
11/09/24 08:18:09 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000
11/09/24 08:18:09 WARN conf.Configuration: mapred.task.id is deprecated. Instead, use mapreduce.task.attempt.id
1 3
a 5
b 3
c 9