No specific problem actually, was just trying to learn and understand, what if some one wants to implement large scale search system using lucene how one should

No specific problem actually, was just trying to learn and understand, what if some one wants to implement large scale search system using lucene how one should go about it. Also, all those options above look interesting, but I am also interested in what sort of thinking/ analysis should be done before you make a decision. In nutshell, I was looking for case studies/ blogs talking about implementing lucene in a distributed fashion. But thanks for your pointers.