program_design.txt

             File 1               File 2             File 3           File 4             File 5               File 6




             						       Mappers compete with each other to grab files to map()





                             Mapper 1                          Mapper 2                         Mapper 3




                      <key,{value,value,value}>            <key,{value,value,value}>          <key,{value,value}>
                      <key,{value}>

                      			↓									↓ 								↓


                      			BLACK BOX: Given a key, return the partition number this key should go to






                      Partition 1					Partition 2						Partition 3					Partition 4


                      	   ↓							↓								↓							↓


                      Reducer 1						Reducer 2						Reducer 3					Reducer 4





                      					Reducer threads sort the keys in the partitions and then reduce()