On Sun, Mar 3, 2013 at 1:41 PM, Jagmohan Chauhan <simplefundumn...@gmail.com > wrote:
> Hi > > I am going through the Capacity Scheduler implementation. There is one > thing i did not understand clearly. > Are you reading the YARN CapacityScheduler or the older, MRv1 one? I'd suggest reading the newer one for any implementation or research goals, for it to be more current and future-applicable. > 1. Does the o ff-switch task refers to a task in which data has to be > fetched over the network. It means its not node-local ? > Off-switch would imply off-rack, i.e. not node local, nor rack-local. > 2. Does off-switch task includes only the tasks for which map input has to > be fetched from a node on a different rack across the switch or it also > includes task where data has to be fetched from another node on same rack > on same switch? > A task's input split is generally supposed to define all locations of available inputs. If the CS is unable to schedule to any of those locations, nor their racks, then it schedules an off-rack (see above) task which has to pull the input from a different rack. > > -- > Thanks and Regards > Jagmohan Chauhan > MSc student,CS > Univ. of Saskatchewan > IEEE Graduate Student Member > > http://homepage.usask.ca/~jac735/ > Feel free to post any further impl. related questions! :) -- Harsh J
