I am curious to know if anyone found the root cause of this. For HTTP processing, there will be an actor, ActorGraphInterpreter created to process each connection with back pressure. The way the graph stages get executed, should give similar effect as EatWhatYouKill policy in Jetty (https://webtide.com/eat-what-you-kill/), providing mechanical sympathy. I haven't done any performance measurements, but code inspection suggests that.
On Monday, 13 November 2017 18:16:13 UTC+5:30, johannes...@lightbend.com wrote: > > I missed this post before. > > I'd like to add another point. Akka Http hasn't been performance tested on > a 40 core machine. The high idle CPU percecntage means that either Akka / > Akka Http is not configured correctly for this amount of cores or that > there are actual contention issues at these levels of scale. It would be > definitely interesting to know what the problem is to offer a better > default experience for running Akka Http on this kind of hardware. > > If you are still listening in, Jakub, it would be nice if you could set > parallelism-max to the number of cores on your machine and/or set > `parallelism-factor = 1` as Patrik suggested. One reason for bad > performance could be that the default parallelism-factor of 3 would lead to > 120 threads battling for resources, starving each other off CPU time maybe > even while keeping some resource. If this alone doesn't increase > performance, a few stack dumps from the server process during steady state > would help because that would likely point out places with high contention. > > For anyone else listening in here, I also wanted to stress, that you need > to put any kind of performance numbers into perspective. We cannot test > everything in every environment and details usually matter in benchmarks. > High CPU idle times like in this case mean that something currently just > doesn't work correctly in this setting. For best performance, you need to > benchmark for yourself on your own hardware and then be prepared to dig > into issues. > > Johannes > >> -- >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
