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Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
courses:mapreduce-tutorial:step-3 [2012/01/29 23:22] majlis |
courses:mapreduce-tutorial:step-3 [2012/01/30 13:51] straka |
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<file perl> | <file perl> | ||
- | package Mapper; | + | package |
use Moose; | use Moose; | ||
with ' | with ' | ||
Line 18: | Line 18: | ||
} | } | ||
- | package | + | package |
use Hadoop:: | use Hadoop:: | ||
my $runner = Hadoop:: | my $runner = Hadoop:: | ||
- | mapper => Mapper-> | + | mapper => My::Mapper-> |
input_format => ' | input_format => ' | ||
output_format => ' | output_format => ' | ||
Line 36: | Line 36: | ||
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. | ||
+ | === Standard input and output === | ||
+ | Standard input and standard output of the Perl script are used to communicate with the Hadoop framework. Therefore you should use standard error output if you want to print some debugging output using '' | ||
===== Exercise ===== | ===== Exercise ===== | ||
Line 41: | Line 43: | ||
To check that your Hadoop environment works, try running a MR job on ''/ | To check that your Hadoop environment works, try running a MR job on ''/ | ||
wget --no-check-certificate ' | wget --no-check-certificate ' | ||
+ | # NOW EDIT THE FILE | ||
+ | # $EDITOR step-3-exercise.pl | ||
rm -rf step-3-out-ex; | rm -rf step-3-out-ex; | ||
less step-3-out-ex/ | less step-3-out-ex/ | ||
Line 47: | Line 51: | ||
You can also download the solution {{: | You can also download the solution {{: | ||
wget --no-check-certificate ' | wget --no-check-certificate ' | ||
+ | # NOW VIEW THE FILE | ||
+ | # $EDITOR step-3-solution.pl | ||
rm -rf step-3-out-sol; | rm -rf step-3-out-sol; | ||
less step-3-out-sol/ | less step-3-out-sol/ |