That is true *only* if you do not have enough slots to run tasks for other jobs of the same user in the entire cluster.
On Mar 5, 2013, at 9:02 PM, Jagmohan Chauhan wrote: > I think i need to re-frame the question a bit. Yes CS supports multiple > jobs in parallel but of different users. If i am submitting 3 different > jobs for a same user at the same time, they are always executed in a FIFO > manner. > Am i correct? > > On Tue, Mar 5, 2013 at 8:55 PM, Harsh J <ha...@cloudera.com> wrote: > >> The CS does support running jobs in parallel. Are you observing just >> the UI or are also noticing a FIFO behavior in logs where assignments >> can be seen with timestamps? >> >> On Wed, Mar 6, 2013 at 9:03 AM, Jagmohan Chauhan >> <simplefunduare .mn...@gmail.com <simplefundumn...@gmail.com>> wrote: >>> Hi All >>> >>> Can someone please reply to my queries? >>> >>> On Sun, Mar 3, 2013 at 5:47 PM, Jagmohan Chauhan < >> simplefundumn...@gmail.com >>>> wrote: >>> >>>> Thanks Harsh. >>>> >>>> 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 <ha...@cloudera.com> wrote: >>>> >>>>> 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 >>>>> >>>> >>>> >>>> >>>> -- >>>> Thanks and Regards >>>> Jagmohan Chauhan >>>> MSc student,CS >>>> Univ. of Saskatchewan >>>> IEEE Graduate Student Member >>>> >>>> http://homepage.usask.ca/~jac735/ >>>> >>> >>> >>> >>> -- >>> Thanks and Regards >>> Jagmohan Chauhan >>> MSc student,CS >>> Univ. of Saskatchewan >>> IEEE Graduate Student Member >>> >>> http://homepage.usask.ca/~jac735/ >> >> >> >> -- >> Harsh J >> > > > > -- > Thanks and Regards > Jagmohan Chauhan > MSc student,CS > Univ. of Saskatchewan > IEEE Graduate Student Member > > http://homepage.usask.ca/~jac735/ -- Arun C. Murthy Hortonworks Inc. http://hortonworks.com/
