Was the number of workers or number of ackers changed across your experiments ? What are the numbers you used ?
When you have many executors, increasing the ackers reduces the complete latency. Thanks and Regards, Devang On 20 May 2015 03:15, "Jeffery Maass" <[email protected]> wrote: > Maybe the difference has to do with where the executors were running. If > your entire topology is running within the same worker, it would mean that > a serialization for the worker to worker networking layer is left out of > the picture. I suppose that would mean the complete latency could > decrease. At the same time, process latency could very well increase, > since all the work is being done within the same worker. My understanding > that process latency is measured from the time the tuple enters the > executor until it leaves the executor. Or was it from the time the tuple > enters the worker until it leaves the worker? I don't recall. > > I bet a firm definition of the latency terms would shed some light. > > Thank you for your time! > > +++++++++++++++++++++ > Jeff Maass <[email protected]> > linkedin.com/in/jeffmaass > stackoverflow.com/users/373418/maassql > +++++++++++++++++++++ > > > On Tue, May 19, 2015 at 9:47 AM, Dima Dragan <[email protected]> > wrote: > >> Thanks Nathan for your answer, >> >> But I`m afraid that you understand me wrong : With increasing executors >> by 32x, each executor's throughput *increased* by 5x, but complete >> latency dropped. >> >> On Tue, May 19, 2015 at 5:16 PM, Nathan Leung <[email protected]> wrote: >> >>> It depends on your application and the characteristics of the io. You >>> increased executors by 32x and each executor's throughput dropped by 5x, so >>> it makes sense that latency will drop. >>> On May 19, 2015 9:54 AM, "Dima Dragan" <[email protected]> wrote: >>> >>>> Hi everyone, >>>> >>>> I have found a strange behavior in topology metrics. >>>> >>>> Let`s say, we have 1 node, 2-core machine. simple Storm topology >>>> Spout A -> Bolt B -> Bolt C >>>> >>>> Bolt B splits message on 320 parts and emits (shuffle grouping) each >>>> to Bolt C. Also Bolts B and C make some read/write operations to db. >>>> >>>> Input flow is continuous and static. >>>> >>>> Based on logic, setting up a more higher number of executors for Bolt C >>>> than number of cores should be useless (the bigger part of threads will be >>>> sleeping). >>>> It is confirmed by increasing execute and process latency. >>>> >>>> But I noticed that complete latency has started to decrease. And I do >>>> not understand why. >>>> >>>> For example, stats for bolt C: >>>> >>>> ExecutorsProcess latency (ms)Complete latency (ms)25.599897.27646.3 >>>> 526.36428.432345.454 >>>> >>>> Is it side effect of IO bound tasks? >>>> >>>> Thanks in advance. >>>> >>>> -- >>>> Best regards, >>>> Dmytro Dragan >>>> >>>> >>>> >> >> >> -- >> Best regards, >> Dmytro Dragan >> >> >> >
