I have a few more questions.
Q1: I found it in my experiments using CS that for any user , its next job
does not start until its current one is finished. Is it true and are there
any exceptions and if true then why is it so? I I did not find any such
condition in the implementation of CS.
Q2: The concept of reserved slots is true only if speculative execution is
on. Am i correct ? If yes,then the code dealing with reserved slots wont be
executed if speculative execution is off?
PS: I am working on MRv1.
On Sun, Mar 3, 2013 at 2:41 AM, Harsh J <[EMAIL PROTECTED]> wrote:
> On Sun, Mar 3, 2013 at 1:41 PM, Jagmohan Chauhan <
> [EMAIL PROTECTED]
> > 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
> > 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
Thanks and Regards
Univ. of Saskatchewan
IEEE Graduate Student Member