Could it be that the TaskManagers are configured with not-enough memory? On Thu, 5 May 2016 at 13:35 Robert Metzger <rmetz...@apache.org> wrote:
> The default value of taskmanager.network.numberOfBuffers is 2048. I would > recommend to use a multiple of that value, for example 16384 (given that > you have enough memory per TaskManager) > > I recommend checking out these slides I created a while ago. They explain > what the network buffers are needed for: > http://www.slideshare.net/robertmetzger1/apache-flink-hands-on#37 > > > On Thu, May 5, 2016 at 1:30 PM, Punit Naik <naik.puni...@gmail.com> wrote: > >> Yes I followed it and changed it to 298 but again it said the same thing. >> The only change was that it now said "required 298, but only 200 available". >> >> Why did it say that? >> >> On Thu, May 5, 2016 at 4:50 PM, Robert Metzger <rmetz...@apache.org> >> wrote: >> >>> Hi, >>> >>> I think you've chosen a good initial value for the parallelism. >>> The higher the parallelism, the more network buffers are needed. I would >>> follow the recommendation from the exception and increase the number of >>> network buffers. >>> >>> On Thu, May 5, 2016 at 11:23 AM, Punit Naik <naik.puni...@gmail.com> >>> wrote: >>> >>>> Hello >>>> >>>> I was running a program with 'parallelism.default' of 384 as I read in >>>> the documentation on Flink's official page that 'parallelism.default' is >>>> "the total number of CPUs in the cluster". I have four machines with 96 >>>> cores on each of them. So 96*4=384. But the program thew an error saying: >>>> >>>> Caused by: java.io.IOException: Insufficient number of network buffers: >>>> required 384, but only 298 available. The total number of network buffers >>>> is currently set to 2048. You can increase this number by setting the >>>> configuration key 'taskmanager.network.numberOfBuffers'. >>>> >>>> What does this mean? And how to choose a proper value for parallelism? >>>> >>>> -- >>>> Thank You >>>> >>>> Regards >>>> >>>> Punit Naik >>>> >>> >>> >> >> >> -- >> Thank You >> >> Regards >> >> Punit Naik >> >
