= 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
}}}
   * [注意] 需要 JAVA_HOME 環境變數才能執行 hadoop namenode
{{{
$ export JAVA_HOME=/usr/lib/jvm/java-6-sun
$ cd hadoop-0.18.2
~/hadoop-0.18.2$ bin/hadoop namenode -format
}}}
   * 編輯 conf/hadoop-site.xml 在 configuration 那一段加入以下設定
{{{
<configuration>
<property>
  <name>fs.default.name</name>
  <value>localhost:5000</value>
 </property>
</configuration>
}}}
   * 用 bin/hadoop namenode 啟動 namenode
{{{
~/hadoop-0.18.2$ bin/hadoop namenode 
<ctrl-C> and come out
}}}
   * 執行 bin/start-dfs.sh
{{{
~/hadoop-0.18.2$ bin/start-dfs.sh
starting namenode, logging to /home/jazz/hadoop-0.18.2/bin/../logs/hadoop-jazz-namenode-hadoop.out
The authenticity of host 'localhost (127.0.0.1)' can't be established.
RSA key fingerprint is 70:3f:8b:f2:b9:a8:de:ea:90:f4:bf:ce:cb:85:7a:eb.
Are you sure you want to continue connecting (yes/no)? yes
localhost: Warning: Permanently added 'localhost' (RSA) to the list of known hosts.
}}}
   * 從這邊的訊息可以知道 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
}}}
{{{
~/hadoop-0.18.2$ bin/hadoop datanode
~/hadoop-0.18.2$ bin/hadoop-daemon.sh start datanode
}}}
   * http://localhost:50070/