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From José Luis Larroque <larroques...@gmail.com>
Subject Re: Reduce stuck at 0% in PageRankBenchmark - Giraph examples
Date Sat, 27 Jun 2015 17:29:28 GMT
Hi again, i get an answer for this in Stack Overflow
<http://stackoverflow.com/questions/29243211/pagerankbenchmark-reduce-at-0-giraph-example/30476769#30476769>,
i will leave it here:
*"Giraph following map-only paradigm. In other words, each worker is
associated with a map task. all of computations is performed within just
map task and communication between map-tasks in order to send / receive
messages is done by using of zookeeper. So, it is unlike of traditional
map-reduce programming paradigm which map outputs transmitted to reducers.
Therefore, there is no reduce task and no map output as well."*

Let's hope that this answer is useful for other's too.

Bye!

2015-03-24 17:46 GMT-03:00 José Luis Larroque <larroquester@gmail.com>:

> I'm sorry, here are the mapper's logs, please tell me if something else is
> needed.
>
> Here they go in the attachments
>
> Thanks!
>
> 2015-03-24 17:30 GMT-03:00 José Luis Larroque <larroquester@gmail.com>:
>
>> Hi guys, i'm testing my Single Node Cluster Giraph installation using
>> PageRankBenchmark example, in the following way:
>>
>> *$HADOOP_HOME/bin/hadoop jar
>>   /usr/local/hadoop/share/hadoop/mapreduce/giraph-examples-1.1.0-for-hadoop-2.4.0-jar-with-dependencies.jar
>> org.apache.giraph.benchmark.PageRankBenchmark -v -V 1000 -e 1 -s 5 -w 1*
>>
>>
>> But after's the mappers complete their job, reducer's don't start. My
>> question is, this is correct?
>>
>>
>> Because i understand that if a mapper get executed, a reducer has to
>> start to take the map's output as an input and finish the work. But i
>> google it, and always PageRankBenchmark (and ShortestPathExample too) ends
>> with Reduce at 0%. Here it's an example :
>> http://stackoverflow.com/questions/25084629/classnotfoundexception-running-giraphrunner-on-a-modified-simpleshortestpathsver
>>
>>
>> So, i don't no if it's ok that in PageRankBenchmark and
>> ShortestPathExample says that Reduce is at 0%
>>
>>
>> I'm using hadoop 2.4, with Phadoop_yarn profile.
>>
>>
>> Hope someone could help me.
>>
>> Bye!
>>
>>
>> Jose
>>
>>
>

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