= 2008-11-04 =

 * Devaraj Das 來訪
   * 09:30 - 10:30 拜會中心主任
   * 11:00 - 12:30 Public Talk Session: "Introduction to Hadoop and Cloud Computing" @ 北群多媒體
   * 14:00 - 17:00 Hands-on Labs (1): "Basics of DFS commands + How to develop !MapReduce program using Hadoop?" @ 北群多媒體

 * Hadoop Hands-on Labs (1)
   * download hadoop-0.18.2
{{{
$ wget http://ftp.twaren.net/Unix/Web/apache/hadoop/core/hadoop-0.18.2/hadoop-0.18.2.tar.gz
$ tar zxvf hadoop-0.18.2.tar.gz
}}}
   *  Hadoop 會用 SSH 進行內部連線，因此需要做 SSH Key exchange
{{{
~$ ssh-keygen
~$ cp .ssh/id_rsa.pub .ssh/authorized_keys
}}}
   * [注意] 需要 JAVA_HOME 環境變數才能執行 hadoop namenode
{{{
$ echo "export JAVA_HOME=/usr/lib/jvm/java-6-sun/jre" >> ~/.bash_profile
$ cd hadoop-0.18.2
}}}
   * [注意] 還需要編輯 conf/hadoop-evn.sh (HADOOP_HOME要設定到你的hadoop安裝目錄)
{{{
export JAVA_HOME=/usr/lib/jvm/java-6-sun
export HADOOP_HOME=/home/jazz/hadoop-0.18.2/
export HADOOP_LOG_DIR=$HADOOP_HOME/logs
export HADOOP_SLAVES=$HADOOP_HOME/conf/slaves
export HADOOP_CONF_DIR=$HADOOP_HOME/conf
}}}
   * 編輯 conf/hadoop-site.xml 在 configuration 那一段加入以下設定
{{{
<property>
  <name>fs.default.name</name>
  <value>hdfs://localhost:9000/</value>
  <description>
    The name of the default file system. Either the literal string
    "local" or a host:port for NDFS.
  </description>
</property>

<property>
  <name>mapred.job.tracker</name>
  <value>localhost:9001</value>
  <description>
    The host and port that the MapReduce job tracker runs at. If
    "local", then jobs are run in-process as a single map and
    reduce task.
  </description>
</property>

}}}
   * 啟動hadoop 的兩道指令
{{{
~/hadoop-0.18.2$ bin/hadoop namenode -format
~/hadoop-0.18.2$ bin/start-all.sh
}}}


 * 完成後可以看到以下三個網頁
   * http://localhost:50030/
   * http://localhost:50060/
   * http://localhost:50070/

 * 可以放的東西上去看看
{{{
~/hadoop-0.18.2$ bin/hadoop dfs -put conf conf
~/hadoop-0.18.2$ bin/hadoop dfs -ls
Found 1 items
drwxr-xr-x   - jazz supergroup          0 2008-11-04 15:56 /user/jazz/conf
}}}