Mahout recommender returns no results -

Mahout recommender returns no results -

my mahout recommender returning no results although looks of evaluator output seems should:

2014-10-15 18:33:36,704 info genericdatamodel - processed 90 users 2014-10-15 18:33:36,735 info abstractdifferencerecommenderevaluator - origin evaluation using 0.99 of genericdatamodel[users:1116,1117,1118...] 2014-10-15 18:33:36,767 info genericdatamodel - processed 89 users 2014-10-15 18:33:36,767 info abstractdifferencerecommenderevaluator - origin evaluation of 75 users 2014-10-15 18:33:36,767 info abstractdifferencerecommenderevaluator - starting timing of 75 tasks in 8 threads 2014-10-15 18:33:36,782 info statscallable - average time per recommendation: 15ms 2014-10-15 18:33:36,782 info statscallable - approximate memory used: 876mb / 1129mb 2014-10-15 18:33:36,782 info statscallable - unable recommend in 0 cases 2014-10-15 18:33:36,845 info abstractdifferencerecommenderevaluator - evaluation result: 1.0599938694784354

i'm assuming "unable recommend in 0 cases" means able recommend in all cases.

i iterate of user id set , see

2014-10-15 18:33:36,923 debug genericuserbasedrecommender - recommending items user id '1164' 2014-10-15 18:33:36,923 debug recommendations are: []

for each id.

i'm reading debug log correctly?

thanks.

not sure log message means, looks stat printed every 1000 itereations must refer past 1000 requests, not time that's guess.

in case seldom able recommend users. there users not recommendations due not plenty usage history them, or usage history not overlap other users. there new users have no preference history , no collaborative filtering recs either. remember using preferences have been expressed, not mean have users represented.

you should have fallback method create recommendations case, popular or promoted items improve nothing.

mahout mahout-recommender