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courses:mapreduce-tutorial:step-3 [2012/01/24 19:14] straka |
courses:mapreduce-tutorial:step-3 [2012/01/25 21:50] straka |
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====== MapReduce Tutorial : Basic mapper ====== | ====== MapReduce Tutorial : Basic mapper ====== | ||
- | The simplest | + | The simplest |
- | ===== Example perl mapper | + | The Hadoop framework silently handles failures. If a mapper |
- | <code perl> | + | ===== Example Perl mapper ===== |
+ | |||
+ | <file perl mapper.pl> | ||
# | # | ||
Line 28: | Line 30: | ||
$runner-> | $runner-> | ||
- | </code> | + | </file> |
The values '' | The values '' | ||
- | Resulting script can be executed using | + | Resulting script can be executed |
perl script.pl run input_directory output_directory | perl script.pl run input_directory output_directory | ||
- | |||
All files in input_directory are processes. The output_directory must not exist. | All files in input_directory are processes. The output_directory must not exist. | ||
+ | |||
+ | ===== Exercise ===== | ||
+ | |||
+ | To check that your Hadoop environment works, try running a MR job on ''/ | ||
+ | |||
+ | {{.: | ||
+ |