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= 實作八 Lab 8 =

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<div style="text-align: center;"><big style="font-weight: bold;"><big>在完全分散模式下編譯 MapReduce 程式<br/>Compiling Hadoop MapReduce Java Program in Hadoop Cluster</big></big></div>
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以下練習，請連線至 hadoop.nchc.org.tw 操作。底下的 hXXXX 等於您的用戶名稱。
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= Practice 1 : Word Count (Basic) =

 * 上傳內容到 HDFS 內[[BR]]upload data to HDFS
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$ mkdir lab8_input
$ echo "I like NCTU Cloud Course." > lab8_input/input1
$ echo "I like nctu Cloud Course, and we enjoy this course." > lab8_input/input2
$ hadoop fs -put lab8_input lab8_input
$ hadoop fs -ls lab8_input
Found 2 items
-rw-r--r--   2 hXXXX supergroup         26 2011-04-19 10:07 /user/hXXXX/lab8_input/input1
-rw-r--r--   2 hXXXX supergroup         52 2011-04-19 10:07 /user/hXXXX/lab8_input/input2
}}}

 * 下載 [http://www.classcloud.org/hadoop4win/WordCount.java WordCount.java] 並存到家目錄;[[BR]]Download [http://www.classcloud.org/hadoop4win/WordCount.java WordCount.java] and save to your home directory
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~$ wget http://www.classcloud.org/hadoop4win/WordCount.java
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 * 運作程式[[BR]]Compile WordCount.java and run it by '''hadoop jar''' command

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$ mkdir MyJava
$ ln -s /opt/hadoop/hadoop-*-core.jar hadoop-core.jar
$ javac -classpath hadoop-core.jar -d MyJava WordCount.java
$ jar -cvf wordcount.jar -C MyJava .
$ hadoop jar wordcount.jar WordCount lab8_input/ lab8_out1/
$ hadoop fs -cat lab8_out1/part-00000
}}}

 * lab8_out1 執行結果 [[BR]]You should see results like this :
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Cloud	2
Course,	1
Course.	1
I	2
NCTU	1
and	1
course.	1
enjoy	1
like	2
nctu	1
this	1
we	1
}}}
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