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From Stefano Bellasio <stefanobella...@gmail.com>
Subject Re: Grouplens dataset Recommenderjob with Hadoop
Date Sat, 20 Nov 2010 11:30:28 GMT
So for example i need to follow the same steps of Wikipedia example in Mahout in Action? then
package it and use with this? Please i need some info just about the correct steps :) Thanks

Il giorno 20/nov/2010, alle ore 12.28, Sean Owen ha scritto:

> Yes, you can't use this recommender directly, since it has no no-arg
> constructor. It by itself is not a complete recommender system -- it doesn't
> have a DataModel. You need to write your own wrapper implementation of
> Recommender which constructs a complete delegate inside. See the examples in
> the javadoc or book.
> 
> On Sat, Nov 20, 2010 at 11:23 AM, Stefano Bellasio <
> stefanobellasio@gmail.com> wrote:
> 
>> Ok, im searching for that, but first of all, before that error i see
>> 
>> java.lang.IllegalStateException: java.lang.NoSuchMethodException:
>> org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.<init>(org.apache.mahout.cf.taste.model.DataModel)
>>       at
>> org.apache.mahout.cf.taste.hadoop.pseudo.RecommenderReducer.setup(RecommenderReducer.java:81)
>>       at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:174)
>>       at
>> org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:566)
>>       at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:408)
>>       at
>> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:216)
>> Caused by: java.lang.NoSuchMethodException:
>> org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender.<init>(org.apache.mahout.cf.taste.model.DataModel)
>>       at java.lang.Class.getConstructor0(Class.java:2706)
>>       at java.lang.Class.getConstructor(Class.java:1657)
>>       at
>> org.apache.mahout.cf.taste.hadoop.pseudo.RecommenderReducer.setup(RecommenderReducer.java:78)
>>       ... 4 more
>> 10/11/20 12:21:50 INFO mapred.JobClient: Job complete: job_local_0001
>> 10/11/20 12:21:50 INFO mapred.JobClient: Counters: 14
>> 10/11/20 12:21:50 INFO mapred.JobClient:   FileSystemCounters
>> 10/11/20 12:21:50 INFO mapred.JobClient:     FILE_BYTES_READ=17546530
>> 10/11/20 12:21:50 INFO mapred.JobClient:     HDFS_BYTES_READ=34695906
>> 10/11/20 12:21:50 INFO mapred.JobClient:     FILE_BYTES_WRITTEN=11751492
>> 10/11/20 12:21:50 INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=17542312
>> 10/11/20 12:21:50 INFO mapred.JobClient:   Map-Reduce Framework
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Reduce input groups=0
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Combine output records=0
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Map input records=1000209
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Reduce shuffle bytes=0
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Reduce output records=0
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Spilled Records=2000418
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Map output bytes=1990807
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Combine input records=0
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Map output records=1000209
>> 10/11/20 12:21:50 INFO mapred.JobClient:     Reduce input records=0
>> 
>> 
>> So is a problem about the class i think, well my command line is:
>> 
>> ../hadoop/bin/hadoop jar core/target/mahout-core-0.5-SNAPSHOT.job.jar
>> org.apache.mahout.cf.taste.hadoop.pseudo.RecommenderJob -i input/ratings.txt
>> -o data/ratings4 --recommenderClassName
>> org.apache.mahout.cf.taste.impl.recommender.GenericItemBasedRecommender
>> 
>> Thanks again
>> 
>> Il giorno 20/nov/2010, alle ore 12.07, Sean Owen ha scritto:
>> 
>>> Sorry but that's something to do with Hadoop, not Mahout. It seems like
>> an
>>> error in your HDFS cluster.
>>> 
>>> On Sat, Nov 20, 2010 at 10:41 AM, Stefano Bellasio <
>>> stefanobellasio@gmail.com> wrote:
>>> 
>>>> Ok Sean, thank you, works very well :) Now when i run hadoop with that
>>>> before finish it say this:
>>>> 
>>>> 
>> 
>> 


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