I'm using mahout-examples-0.7-cdh4.5.0-job.jar locally. But I tried on EMR (with mahout-examples-0.8-job.jar this time) on 3000 tracks and I also had empty result files. Should I send you the dataset on your apache address (it is only 140Ko)?
Quentin 2014/1/21 Sebastian Schelter <[email protected]> > Hmm, strange. Which version of mahout are you using? Do you run the 1200 > tracks job locally or on a cluster? Can you share your input file (in > private)? > > --sebastian > > > > On 01/21/2014 02:34 PM, Quentin-Gabriel Thurier wrote: > >> Hi Sebastian >> >> I tested the job on a tiny example (50 tracks) : >> >> mahout itemsimilarity --input input/msd_sample/mahout5 --output >>> >> output/mahout5 --similarityClassname SIMILARITY_EUCLIDEAN_DISTANCE >> --booleanData false --maxSimilaritiesPerItem 1 >> >> *1st row of the output: >> >> -2135949055 -335737401 0.09939478338891584 >> >> *related rows from the input: >> >> 1,-2135949055,230.42567 >> 2,-2135949055,0.0 >> 3,-2135949055,0.0 >> 4,-2135949055,-3.96 >> 5,-2135949055,-1.0 >> 6,-2135949055,96.897 >> 1,-335737401,222.35384 >> 2,-335737401,0.0 >> 3,-335737401,0.0 >> 4,-335737401,-5.232 >> 5,-335737401,-1.0 >> 6,-335737401,100.812 >> >> This is correct : >> 1/(1+(230.42567-222.35384)^2+(-3.96--5.232)^2+(96.897-100.812)^2) >> = 0.09939483 >> >> I don't have any exception except the usual warning : WARN >> mapred.JobClient: Use GenericOptionsParser for parsing the arguments. >> Applications should implement Tool for the same. >> >> Then I take 1200 tracks (the 50 previous are included in the 1200) the job >> don't fail but part-r-00000 is empty. As previously I only have a warning >> and the input looks like: >> >> 1,524572804,192.522 >> 2,524572804,0.0 >> 3,524572804,0.0 >> 4,524572804,-5.902 >> 5,524572804,-1.0 >> 6,524572804,123.756 >> 1,-1821170097,269.81833 >> 2,-1821170097,0.0 >> 3,-1821170097,0.0 >> 4,-1821170097,-13.496 >> 5,-1821170097,0.26586103 >> 6,-1821170097,86.643 >> >> Quentin >> >> >> 2014/1/21 Sebastian Schelter <[email protected]> >> >> Hi Quentin, >>> >>> Have you checked the log to ensure that you don't get any exceptions >>> during the computation? >>> >>> Could you test the job with a tiny example where you can calculate the >>> result by hand? >>> >>> Can you share an input file on which this job fails? >>> >>> --sebastian >>> >>> >>> On 01/21/2014 11:22 AM, Quentin-Gabriel Thurier wrote: >>> >>> I encounter few troubles with Mahout that I can't sort out.. >>>> >>>> The context is that I'm trying to calculate pairwise euclidean distances >>>> between music tracks based on 6 audio features per track. My input for >>>> the >>>> mahout job is a text file which looks like this: >>>> >>>> feature_id,track_id,feature_value >>>> <integer>,< integer>,<double> >>>> >>>> This command works locally for less than 600 tracks (based on >>>> mahout-core-0.7-cdh4.5.0-job.jar): >>>> >>>> mahout itemsimilarity --input input/msd_sample/mahout --output >>>> output/mahout --similarityClassname >>>> SIMILARITY_EUCLIDEAN_DISTANCE --booleanData false >>>> --maxSimilaritiesPerItem 1 >>>> >>>> But for more tracks I get an empty file part-r-0000. I tried to decrease >>>> the --threshold parameter but I still don't have any result. >>>> >>>> I also tried to launch the job on aws EMR with the equivalent input for >>>> 3000 tracks (based on mahout-core-0.8-job.jar): >>>> >>>> org.apache.mahout.cf.taste.hadoop.similarity.item.ItemSimilarityJob >>>> --input >>>> s3n://hadoop-filrouge/input/msd-sample/mahout --output >>>> s3n://hadoop-filrouge/output/mahout/01202014-itemsimilarity >>>> --similarityClassname SIMILARITY_EUCLIDEAN_DISTANCE --booleanData false >>>> --maxSimilaritiesPerItem 1 >>>> >>>> The job runs successfully but I get 17 empty part-r-000xx.. >>>> >>>> I'm totally stuck right now and I'm running out of idea to fix this >>>> issue. >>>> So if anydody only have a little idea of what is going on, that could >>>> really help. >>>> >>>> Many thanks, >>>> >>>> >>>> >>> >> >
