Hadoop API is a pain. Well, it is fine when doing the vanilla mapreduce, but once one steps away from that, things get ugly real fast with the zoo of Jobs, Tasks, Contexts, two mapred/mapreduce apis which do the same thing, plus hadoop.23 specific calls. I haven't touched Hadoop 1.0 yet, though I doubt they have cleaned all the mess. Hope they will streamline the API by 2.0