所以我写了两个perl脚本来练习map reduce。程序应该计算我放在目录中的一堆文本文件中的所有单词。
这是我的mapper.pl
# !/usr/bin/perl
use 5.010;
use strict;
use warnings;
while(my $line = <>) {
my @words = split(' ', $line);
foreach my $word(@words) {
print "$word \t 1\n";
}
}
这是我的减速机.pl
# !/bin/usr/perl
use 5.010;
use warnings;
my $currentWord = "";
my $currentCount = 0;
## Use this block for testing the reduce script with some test data.
# Open the test file
# open(my $fh, "<", "testdata.txt");
# while(!eof $fh) {}
while(my $line = <>) {
#Remove the \n
chomp $line;
#Index 0 is the word, index 1 is the count value
my @lineData = split('\t', $line);
my $word = $lineData[0];
my $count = $lineData[1];
if($currentWord eq $word) {
$currentCount = $currentCount + $count;
} else {
if($currentWord ne "") {
#Output the key we're finished working with
print "$currentWord \t $currentCount \n";
}
#Switch the current variables over to the next key
$currentCount = $count;
$currentWord = $word;
}
}
# deal with the last loop
print "$currentWord \t $currentCount \n";
因此,当我使用hadoop流式处理命令运行这些命令时:
bin/hadoop jar contrib/streaming/hadoop-streaming-1.1.2.jar -file /home/hduser/countWords/mapper.pl -mapper /home/hduser/countWords/mapper.pl -file /home/hduser/countWords/reducer.pl -reducer /home/hduser/countWords/reducer.pl -input /user/hduser/testData/* -output /user/hduser/testData/output/*
我得到以下错误:
13/07/19 11:36:33 INFO streaming.StreamJob: map 0% reduce 0%
13/07/19 11:36:39 INFO streaming.StreamJob: map 9% reduce 0%
13/07/19 11:36:40 INFO streaming.StreamJob: map 64% reduce 0%
13/07/19 11:36:41 INFO streaming.StreamJob: map 73% reduce 0%
13/07/19 11:36:44 INFO streaming.StreamJob: map 82% reduce 0%
13/07/19 11:36:45 INFO streaming.StreamJob: map 100% reduce 0%
13/07/19 11:36:49 INFO streaming.StreamJob: map 100% reduce 11%
13/07/19 11:36:53 INFO streaming.StreamJob: map 100% reduce 0%
13/07/19 11:37:02 INFO streaming.StreamJob: map 100% reduce 17%
13/07/19 11:37:03 INFO streaming.StreamJob: map 100% reduce 33%
13/07/19 11:37:06 INFO streaming.StreamJob: map 100% reduce 17%
13/07/19 11:37:08 INFO streaming.StreamJob: map 100% reduce 0%
13/07/19 11:37:16 INFO streaming.StreamJob: map 100% reduce 33%
13/07/19 11:37:21 INFO streaming.StreamJob: map 100% reduce 0%
13/07/19 11:37:31 INFO streaming.StreamJob: map 100% reduce 33%
13/07/19 11:37:35 INFO streaming.StreamJob: map 100% reduce 17%
13/07/19 11:37:38 INFO streaming.StreamJob: map 100% reduce 100%
13/07/19 11:37:38 INFO streaming.StreamJob: To kill this job, run:
13/07/19 11:37:38 INFO streaming.StreamJob: /usr/local/hadoop/libexec/../bin/hadoop job -Dmapred.job.tracker=shiv0:54311 -kill job_201307031312_0065
13/07/19 11:37:38 INFO streaming.StreamJob: Tracking URL: http://shiv0:50030/jobdetails.jsp?jobid=job_201307031312_0065
13/07/19 11:37:38 ERROR streaming.StreamJob: Job not successful. Error: # of failed Reduce Tasks exceeded allowed limit. FailedCount: 1. LastFailedTask: task_201307031312_0065_r_000001
13/07/19 11:37:38 INFO streaming.StreamJob: killJob... Streaming Command Failed!
一段时间以来,我一直在想我做错了什么,我一直在挠头。有人对我如何诊断这个有什么建议吗?
2条答案
按热度按时间llew8vvj1#
我犯了一个极其愚蠢的错误。。reducer.pl的shbang行不正确。我有
而不是
laik7k3q2#
bin/hadoop jar contrib/streaming/hadoop-streaming-1.1.2.jar-file/home/hduser/countwords/mapper.py-mapper/home/hduser/countwords/mapper.py-file/home/hduser/countwords/reducer.py-reducer/home/hduser/countwords/reducer.py-input/user/hduser/testdata/-output/user/hduser/testdata/output/
为什么要调用.py文件?您不应该调用perl文件,即reducer.pl而不是reducer.py吗