That all sounds fine, should be no problem with this usage pattern. I don't think the issue is where you think it is -- The problem seemed to be with the FastMap used to cache recommendations. Is there anything interesting about how this is used? I just added a couple unit tests for the cache to try to reproduce it but didn't see anything.
You can remove CachingRecommender to see what happens but that would be a shame since it's just avoiding the problem. If there's an issue I'm keen to track it down. I can't figure out what the issue is. Maybe I can add some asserts to the code that could trigger some signs of a problem. 2009/12/5 施伟伟 <[email protected]>: > Thanks for reply. > It does not happen all the time. I saw this twice and could not easily > reproduce it. > Next time I will try testing it with jpda enabled. > > I am not sure if I am doing something wrong in the data model. > First I fill the FastMap with data read from external data source. > Then I iterate all entries in FastMap and find a set of items that I don't > need. > Finally I iterate the entries again to remove those items from FastMap. If > the item set of any userID becomes empty, the userID will be removed from > FastMap too. > > Maybe I should do these outside mahout using ordinary Map? > > Thanks, > Weiwei >
