Oh thanks. Great material On Mon, Oct 12, 2015 at 6:53 AM, Viktor Klang <[email protected]> wrote:
> > > On Mon, Oct 12, 2015 at 12:44 PM, Maatary Okouya <[email protected]> > wrote: > >> Just to be clear, the meaning of parallelism is not stricto sensus. In >> other words, when i think parallelism, i think parallel execution. While >> given that we are not at 1 thread per OS reported processor, but 3, i >> conclude that this is more like a concurrency factor. I mean concurrent is >> not parallel. That was the my original confusion i.e. understanding what >> is meant by parallelism here. >> >> But i guess this is parallel in the loose sense, as in scala parallel >> collection. They can be fully operated in parallel but r actually operated >> concurrently. >> >> I just wanted to be clear on the semantic? Is my understanding right ? We >> are talking of parallelism in a loose sense and not stricto sensus. >> > > Id' recommend reading up on the following for understanding ForkJoinPool: > https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ForkJoinPool.html > > We chose to use the same nomenclature (inventing our own would be weird, > don't you agree?) > > >> On Mon, Oct 12, 2015 at 6:26 AM, Maatary Okouya <[email protected]> >> wrote: >> >>> Understood, Many thanks. >>> >>> On Mon, Oct 12, 2015 at 6:08 AM, Viktor Klang <[email protected]> >>> wrote: >>> >>>> >>>> >>>> On Mon, Oct 12, 2015 at 12:00 PM, Maatary Okouya < >>>> [email protected]> wrote: >>>> >>>>> Thank you victor. >>>>> >>>>> However, >>>>> >>>>> 1 - does it means that akka configuration is not related to the number >>>>> of cores but the processor only ? So wether your processor has two cores >>>>> or >>>>> 4 cores or just 1, is not taken into account at all, i.e. in deciding how >>>>> much thread you would allocate in your thread pool? >>>>> >>>>> >>>> Or >>>>> >>>>> 2 - by processor u actually mean "a core" I.e in "4 processors" your >>>>> actually mean a quad-core processor or dual-core processor hyper-threaded. >>>>> >>>>> >>>>> Could you please clarify this "processor" thing in term of typical >>>>> machine configuration ? >>>>> >>>> >>>> No, it's about the number of processors available to the JVM. It's >>>> about what the OS reports. >>>> >>>> https://docs.oracle.com/javase/7/docs/api/java/lang/Runtime.html#availableProcessors() >>>> >>>> So for a computer with 2 CPU-slots with 4 cores each with >>>> HyperThreading, it would be 2 * 4 * 2 = 16 processors >>>> >>>> >>>>> >>>>> >>>>> On Mon, Oct 12, 2015 at 3:55 AM Viktor Klang <[email protected]> >>>>> wrote: >>>>> >>>>>> Hi Maatary, >>>>>> >>>>>> On Sun, Oct 11, 2015 at 9:27 PM, Maatary Okouya < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> As I understood that the fork-join-executor is the default >>>>>>> dispatcher when non is provided when creating the actor system >>>>>>> Can someone explain me the following: >>>>>>> >>>>>>> >>>>>>> 1. fork-join-executor { >>>>>>> 2. # Min number of threads to cap factor-based parallelism >>>>>>> number to >>>>>>> 3. parallelism-min = 8 >>>>>>> 4. >>>>>>> 5. # The parallelism factor is used to determine thread pool >>>>>>> size using the >>>>>>> 6. # following formula: ceil(available processors * factor). >>>>>>> Resulting size >>>>>>> 7. # is then bounded by the parallelism-min and parallelism-max >>>>>>> values. >>>>>>> 8. parallelism-factor = 3.0 >>>>>>> 9. >>>>>>> 10. # Max number of threads to cap factor-based parallelism >>>>>>> number to >>>>>>> 11. parallelism-max = 64 >>>>>>> 12. >>>>>>> 13. # Setting to "FIFO" to use queue like peeking mode which >>>>>>> "poll" or "LIFO" to use stack >>>>>>> 14. # like peeking mode which "pop". >>>>>>> 15. task-peeking-mode = "FIFO" >>>>>>> 16. } >>>>>>> >>>>>>> >>>>>>> ALthough i understand each word, i don't understand the full >>>>>>> semantic of what is explained here. >>>>>>> >>>>>>> >>>>>>> - What does mean ceil ? in ceil(available processors * factor) >>>>>>> >>>>>> >>>>>> In short: "Rounded up": >>>>>> https://www.google.se/search?q=ceil >>>>>> >>>>>> >>>>>>> - What means factor-based parallelism ? >>>>>>> >>>>>> >>>>>> It means that the factor given in "parallelism-factor" will be what >>>>>> the available number of processors will be multiplied with. >>>>>> >>>>>> Scenario: >>>>>> >>>>>> available processors = 4 >>>>>> parallelism-factor = 0.6 >>>>>> >>>>>> ceil(4 * 0.6) == 3 >>>>>> >>>>>> this means that the resulting desired parallelism is 3 >>>>>> >>>>>> Does that make sense? >>>>>> >>>>>> >>>>>>> >>>>>>> Can someone overall explain to me in english what means the >>>>>>> configuration above. By reading many post here and there, i had somewhat >>>>>>> understood that by default, akka, would set up a threadPoolexecutor that >>>>>>> allocate and thread per core. Hence if you have 2 two core processor, >>>>>>> you >>>>>>> would end up with 4 threads. Which is how much parallel you can really >>>>>>> be >>>>>>> anyway. Above that it is concurrent but not full strictly speaking >>>>>>> parallel. Although that is another issue. >>>>>>> >>>>>>> >>>>>>> So if someone could explain the above configuration in term of >>>>>>> processor and core and the resulting number of threads with 2 examples >>>>>>> of >>>>>>> machine (per their processor configuration) that would be great. >>>>>>> >>>>>>> -- >>>>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>> >>>>>>>>>> Check the FAQ: >>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>> >>>>>>>>>> Search the archives: >>>>>>> https://groups.google.com/group/akka-user >>>>>>> --- >>>>>>> >>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Akka User List" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to [email protected]. >>>>>> >>>>>> >>>>>>> To post to this group, send email to [email protected]. >>>>>>> Visit this group at http://groups.google.com/group/akka-user. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Cheers, >>>>>> √ >>>>>> >>>>>> -- >>>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>> >>>>>>>>>> Check the FAQ: >>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>> >>>>>>>>>> Search the archives: >>>>>> https://groups.google.com/group/akka-user >>>>>> --- >>>>>> You received this message because you are subscribed to a topic in >>>>>> the Google Groups "Akka User List" group. >>>>>> To unsubscribe from this topic, visit >>>>>> https://groups.google.com/d/topic/akka-user/eR4fShuWm6w/unsubscribe. >>>>>> To unsubscribe from this group and all its topics, send an email to >>>>>> [email protected]. >>>>>> To post to this group, send email to [email protected]. >>>>>> Visit this group at http://groups.google.com/group/akka-user. >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> -- >>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>> >>>>>>>>>> Check the FAQ: >>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>> >>>>>>>>>> Search the archives: >>>>> https://groups.google.com/group/akka-user >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Akka User List" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> Visit this group at http://groups.google.com/group/akka-user. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> >>>> >>>> -- >>>> Cheers, >>>> √ >>>> >>>> -- >>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>> >>>>>>>>>> Check the FAQ: >>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>> >>>>>>>>>> Search the archives: >>>> https://groups.google.com/group/akka-user >>>> --- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "Akka User List" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/akka-user/eR4fShuWm6w/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at http://groups.google.com/group/akka-user. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >> -- >> >>>>>>>>>> Read the docs: http://akka.io/docs/ >> >>>>>>>>>> Check the FAQ: >> http://doc.akka.io/docs/akka/current/additional/faq.html >> >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user >> --- >> You received this message because you are subscribed to the Google Groups >> "Akka User List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/akka-user. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Cheers, > √ > > -- > >>>>>>>>>> Read the docs: http://akka.io/docs/ > >>>>>>>>>> Check the FAQ: > http://doc.akka.io/docs/akka/current/additional/faq.html > >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user > --- > You received this message because you are subscribed to a topic in the > Google Groups "Akka User List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/akka-user/eR4fShuWm6w/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. 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