Integrating MPI with map-reduce is currently difficult and/or very ugly, however. Not impossible and there are hackish ways to do the job, but they are hacks.
There is an project out of Sandia National Lab that puts MR and MPI together in a library if you're interested --> http://www.sandia.gov/~sjplimp/mapreduce.html
The project isn't mature yet, and I haven't actually used it myself. -- -- Grant Mackey PhD student Computer Engineering University of Central Florida
