在Ubuntu上装Hadoop
在装Hadoop之前首先需要：
1.java1.6.x 最好是sun的，1.5.x也可以
2.ssh
安装ssh
$ sudo apt-get install ssh
$ sudo apt-get install rsync
下载Hadoop
从http://hadoop.apache.org/core/releases.html 下载最近发布的版本
最好为hadoop创建一个用户:
比如创建一个group为hadoop user为hadoop的用户以及组
$ sudo addgroup hadoop
$ sudo adduser --ingroup hadoop hadoop
解压下载的hadoop文件，放到/home/hadoop目录下 名字为hadoop
配置JAVA_HOME:
gedit ~/hadoop/conf/hadoop-env.sh
将
Java代码
1. # The java implementation to use. Required.
2. # export JAVA_HOME=/usr/lib/j2sdk1.5-sun
# The java implementation to use. Required.
# export JAVA_HOME=/usr/lib/j2sdk1.5-sun
修改成java的安装目录：（我的是：/usr/lib/jvm/java-6-sun-1.6.0.15）
# The java implementation to use. Required.
export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0.15
现在可以使用单节点的方式运行：
$ cd hadoop
$ mkdir input
$ cp conf/*.xml input
$ bin/hadoop jar hadoop-*-examples.jar grep input output 'dfs[a-z.]+'
$ cat output/*
Pseudo-distributed方式跑:
配置ssh
$ su - hadoop
$ ssh-keygen -t rsa -P ""
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:
9d:47:ab:d7:22:54:f0:f9:b9:3b:64:93:12:75:81:27 hadoop@ubuntu
让其不输入密码就能登录：
hadoop@ubuntu:~$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
使用：
$ ssh localhost
看看是不是直接ok了。
hadoop配置文件：
conf/core-site.xml
Java代码
1. <?xml version="1.0"?>
2. <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
3.
4. <!-- Put site-specific property overrides in this file. -->
5.
6. <configuration>
7. <property>
8. <name>hadoop.tmp.dir</name>
9. <value>/home/hadoop/hadoop-datastore/hadoop-${user.name}</value>
10. </property>
11. <property>
12. <name>fs.default.name</name>
13. <value>hdfs://localhost:9000</value>
14. </property>
15. </configuration>
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>/home/hadoop/hadoop-datastore/hadoop-${user.name}</value>
</property>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
hadoop.tmp.dir配置为你想要的路径，${user.name} 会自动扩展为运行hadoop的用户名
conf/hdfs-site.xml
Xml代码
1. <configuration>
2. <property>
3. <name>dfs.replication</name>
4. <value>1</value>
5. </property>
6. </configuration>
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
dfs.replication为默认block复制数量
conf/mapred-site.xml
Xml代码
1. <configuration>
2. <property>
3. <name>mapred.job.tracker</name>
4. <value>localhost:9001</value>
5. </property>
6. </configuration>
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
</configuration>
执行
格式化分布式文件系统：
$ bin/hadoop namenode -format
启动hadoop：
Java代码
1. $ bin/start-all.sh
$ bin/start-all.sh
可以从
NameNode - http://localhost:50070/
JobTracker - http://localhost:50030/
查看NameNode和JobTracker
运行例子：
$ bin/hadoop fs -put conf input
$ bin/hadoop jar hadoop-*-examples.jar grep input output 'dfs[a-z.]+'
look at the run result:
$ bin/hadoop fs -get output output
$ cat output/*
参考： 1、http://hadoop.apache.org/common/docs/current/quickstart.html
2、http://www.michael-noll.com/wiki /Running_Hadoop_On_Ubuntu_Linux_%28Single-Node_Cluster%29