1.下载 Hadoop-0.20.2版本并解压, tar -xvzf
2. edit the file conf/hadoop-env.sh to define at least JAVA_HOME to be the root of your Java installation.
加上这一句 export JAVA_HOME=/Library/Java/Home
3.Try the following command: $ bin/hadoop This will display the usage documentation for the hadoop script.
4. 更改 conf文件夹里的 配置文件
conf/core-site.xml:
<configuration> <property> <name>fs.default.name</name> <value>hdfs://localhost:9000</value> </property> </configuration>
conf/hdfs-site.xml:
<configuration> <property> <name>dfs.replication</name> <value>1</value> </property> </configuration>
conf/mapred-site.xml:
<configuration> <property> <name>mapred.job.tracker</name> <value>localhost:9001</value> </property> </configuration>
5. 配置ssh
Now check that you can ssh to the localhost without a passphrase: $ ssh localhost
If you cannot ssh to localhost without a passphrase, execute the following commands: $ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa $ cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
6. 执行Hadoop
Format a new distributed-filesystem: $ bin/hadoop namenode -format
Start the hadoop daemons: $ bin/start-all.sh
The hadoop daemon log output is written to the ${HADOOP_LOG_DIR} directory (defaults to ${HADOOP_HOME}/logs).
Browse the web interface for the NameNode and the JobTracker; by default they are available at:
NameNode - http://localhost:50070/ JobTracker - http://localhost:50030/
7. 运行hadoop 的 hello word 程序
mkdir input
并在里面放置你想统计的文本文件
将文件夹放入hdfs里面
bin/hadoop dfs -put input input
执行example word count 程序 ，输入文件夹为hdfs里面名字为input的，输出文件夹为output
bin/hadoop jar hadoop-0.20.2-examples.jar wordcount input output
将hdfs里面的output文件夹取出到本地命名为output bin/hadoop -dfs get output output
查看里面的词频统计内容
cat output/*
8. helpful link http://www.cs.brandeis.edu/~rshaull/cs147a-fall-2008/hadoop-troubleshooting/
里面列出来了一些安装出现的简单问题，譬如当我运行 eamples时遇见过
java.io.IOException: Not a file: hdfs://localhost:9000/user/ross/input/conf
里面列出来了是因为在hdfs里面的input文件夹没有删除，我们需要
bin/hadoop dfs -rmr input bin/hadoop dfs -put conf input
9. 引用
安装流程参考 https://hadoop.apache.org/docs/r1.2.1/single_node_setup.html
