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= 實作二： HDFS 指令操作練習  =

 == 前言 ==

 * 此部份接續實做一
    
 == Content 1. 基本操作 ==
 === 1.1 瀏覽你HDFS目錄  === 

 === 1.2 上傳資料到HDFS目錄 === 
 
 === 1.3 下載HDFS的資料到本地目錄 === 
  
 == Content 2. Hadoop 運算命令 == 
  
 === 2.1 Hadoop運算命令 grep ===  
 
 === 2.2 Hadoop運算命令 WordCount ===
 
 === 2.3 更多運算命令 ==
 請參考 [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/examples/package-summary.html org.apache.hadoop.examples]
 
 || || || 
 || AggregateWordCount  || 	This is an example Aggregated Hadoop Map/Reduce application. || 
 || AggregateWordCount.WordCountPlugInClass  ||  || 	 
 || AggregateWordHistogram  || 	This is an example Aggregated Hadoop Map/Reduce application. || 
 || AggregateWordHistogram.AggregateWordHistogramPlugin 	 ||  ||  
 || DBCountPageView  || 	This is a demonstrative program, which uses DBInputFormat for reading the input data from a database, and DBOutputFormat for writing the data to the database. || 
 || ExampleDriver  || 	A description of an example program based on its class and a human-readable description. || 
 || Grep 	  ||  || 
 || Join  || 	This is the trivial map/reduce program that does absolutely nothing other than use the framework to fragment and sort the input values. || 
 || MultiFileWordCount  || 	MultiFileWordCount is an example to demonstrate the usage of MultiFileInputFormat. || 
 || MultiFileWordCount.MapClass 	 || This Mapper is similar to the one in WordCount.MapClass. || 
 || MultiFileWordCount.MultiFileLineRecordReader  || 	RecordReader is responsible from extracting records from the InputSplit. || 
 || MultiFileWordCount.MyInputFormat  || 	To use MultiFileInputFormat, one should extend it, to return a (custom) RecordReader. || 
 || MultiFileWordCount.WordOffset  || 	This record keeps <filename,offset> pairs. || 
 || PiEstimator  || 	A Map-reduce program to estimaate the valu eof Pi using monte-carlo method. || 
 || PiEstimator.PiMapper  || 	Mappper class for Pi estimation.
PiEstimator.PiReducer 	  || 
 || RandomTextWriter 	 || This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task writes a large unsorted random sequence of words. || 
 || RandomWriter  || 	This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task write a large unsorted random binary sequence file of BytesWritable. || 
 || SleepJob  || 	Dummy class for testing MR framefork. || 
 || Sort<K,V>  || 	This is the trivial map/reduce program that does absolutely nothing other than use the framework to fragment and sort the input values. || 
 || WordCount  || 	This is an example Hadoop Map/Reduce application. || 
 || WordCount.MapClass  || 	Counts the words in each line. || 
 || WordCount.Reduce  || 	A reducer class that just emits the sum of the input values. || 
   
 
 == Content 6. 使用網頁Gui == 
 
 == 練習 ==