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 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.
