On Mon, 06 Jun 2011 09:18:45 -0400, <dar...@ontrenet.com> wrote: > I never understood how hadoop can throttle an inter-rack fiber switch. > Its supposed to operate on the principle of move-the-code to the data > because of the I/O cost of moving the data, right?
But what happens when a reducer on rack A gets most of its input from mappers on rack A, but needs a serious chunk of data from mappers on racks, B, C, D...
