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courses:mapreduce-tutorial:step-10 [2012/01/25 22:12]
straka
courses:mapreduce-tutorial:step-10 [2012/01/31 09:38]
straka Change Perl commandline syntax.
Line 10: Line 10:
  
 <file perl> <file perl>
-package Mapper;+package My::Mapper;
 ... ...
  
-package Reducer;+package My::Reducer;
 ... ...
  
-package Main;+package main;
 use Hadoop::Runner; use Hadoop::Runner;
  
 my $runner = Hadoop::Runner->new( my $runner = Hadoop::Runner->new(
-  mapper => Mapper->new(), +  mapper => My::Mapper->new(), 
-  combiner => Reducer->new(), # Specify the combiner. +  combiner => My::Reducer->new(), # Specify the combiner. 
-  reducer => Reducer->new(),+  reducer => My::Reducer->new(),
   input_format => 'KeyValueTextInputFormat');   input_format => 'KeyValueTextInputFormat');
 ... ...
Line 29: Line 29:
 ===== Exercise ===== ===== Exercise =====
  
-Compare the effect of adding the combiner to a MR job which counts occurrences of words in ''/home/straka/wiki/cs-text-medium'': {{:courses:mapreduce-tutorial:step-5-solution1.txt|wc-without-combiner.pl}} and {{:courses:mapreduce-tutorial:step-10.txt|wc-with-combiner.pl}}.+Compare the effect of adding the combiner to a MR job which counts occurrences of words in ''/home/straka/wiki/cs-text-medium'': {{:courses:mapreduce-tutorial:step-5-solution1.txt|step-10-wc-without-combiner.pl}} and {{:courses:mapreduce-tutorial:step-10.txt|step-10-wc-with-combiner.pl}}. 
 +  wget --no-check-certificate 'https://wiki.ufal.ms.mff.cuni.cz/_media/courses:mapreduce-tutorial:step-5-solution1.txt' -O 'step-10-wc-without-combiner.pl' 
 +  # NOW VIEW THE FILE 
 +  # $EDITOR step-10-wc-without-combiner.pl 
 +  rm -rf step-10-out-wout; time perl step-10-wc-without-combiner.pl /home/straka/wiki/cs-text-medium/ step-10-out-wout 
 +   
 +  wget --no-check-certificate 'https://wiki.ufal.ms.mff.cuni.cz/_media/courses:mapreduce-tutorial:step-10.txt' -O 'step-10-wc-with-combiner.pl' 
 +  # NOW VIEW THE FILE 
 +  # $EDITOR step-10-wc-with-combiner.pl 
 +  rm -rf step-10-out-with; time perl step-10-wc-with-combiner.pl /home/straka/wiki/cs-text-medium/ step-10-out-with
  
 How would you explain the results? How would you explain the results?
  
 +----
 +
 +<html>
 +<table style="width:100%">
 +<tr>
 +<td style="text-align:left; width: 33%; "></html>[[step-9|Step 9]]: Hadoop properties.<html></td>
 +<td style="text-align:center; width: 33%; "></html>[[.|Overview]]<html></td>
 +<td style="text-align:right; width: 33%; "></html>[[step-11|Step 11]]: Initialization and cleanup of MR tasks, performance of combiners.<html></td>
 +</tr>
 +</table>
 +</html>

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