One question about distributed ARQ

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Dear developers:
          I am a student. My name is Li Zhiguo. Recently , I am reseraching on 
how to develop a  SPARQL query engine which will run over Hadoop clusters . I 
plan to use to Jena API and do some extensions on ARQ ,but I don't know how to 
begin my plan .Does someone of you have done some works on this direction?
         What should I do firstly  ? 
    
         Best wishes to you all !