Robert, Thanks! This really does clear things up. The results were a little surprising at first blush since I believe part of the idea behind channels is to be able to serve more requests concurrently than a single-threaded approach typically allows. This is why I don't think this benchmark alone is very useful. We already knew it would be slower to serve requests with a single worker given the overhead as you described. So what does this benchmark get us? Is it merely to characterize the performance difference in the pathological case? I think ramping up the number of workers on a single machine would be an interesting next step, no?
Anyway, thanks for taking the time to do this work and help us understand the results. On Sunday, September 25, 2016 at 8:23:45 PM UTC-5, Robert Roskam wrote: > > Hey Chris, > > Sure thing! I'm going to add a little color to this; probably a little > more than required. > > I have gunciorn for comparison on both graphs because channels supports > HTTP requests, so we wanted to see how it would do against a serious > production environment option. I could have equally done uwsgi. I chose > gunicorn out of convenience. It serves as a control for the redis channels > setup. > > The main point of comparison is to say: yeah, Daphne has an order of > magnitude higher latency than gunicorn, and as a consequence, it's > throughput in the same period of time as gunicorn is less. This really > shouldn't be surprising. Channels is processing an HTTP request, stuffing > it in a redis queue, having a worker pull it out, process it, and then send > a response back through the queue. This has some innate overhead in it. > > You'll note I didn't include IPC for latency comparison. It's because it's > so bad that it would make the graph unreadable. You can get the sense of > that when you see it's throughput. So don't use it for serious production > machines. Use it for a dev environment when you don't want a complex setup, > or use it with nginx splitting traffic for just websockets if you don't > want to run redis for some reason. > > > > Robert Roskam > > On Wednesday, September 14, 2016 at 10:21:27 AM UTC-4, Chris Foresman > wrote: >> >> Yes. Honestly, just explain what these results mean in words, because I >> cannot turn these graphs into anything meaningful on my own. >> >> >> >> On Monday, September 12, 2016 at 8:41:05 PM UTC-5, Robert Roskam wrote: >>> >>> Hey Chris, >>> >>> The goal of these tests is to see how channels performs with normal HTTP >>> traffic under heavy load with a control. In order to compare accurately, I >>> tried to eliminate variances as much as possible. >>> >>> So yes, there was one worker for both Redis and IPC setups. I provided >>> the supervisor configs, as I figured those would be helpful in describing >>> exactly what commands were run on each system. >>> >>> Does that help bring some context? Or would you like for me to elaborate >>> further on some point? >>> >>> Thanks, >>> Robert >>> >>> >>> On Monday, September 12, 2016 at 2:38:59 PM UTC-4, Chris Foresman wrote: >>>> >>>> Is this one worker each? I also don't really understand the implication >>>> of the results. There's no context to explain the numbers nor if one >>>> result >>>> is better than another. >>>> >>>> On Sunday, September 11, 2016 at 7:46:52 AM UTC-5, Robert Roskam wrote: >>>>> >>>>> Hello All, >>>>> >>>>> The following is an initial report of Django Channels performance. >>>>> While this is being shared in other media channels at this time, I fully >>>>> expect to get some questions or clarifications from this group in >>>>> particular, and I'll be happy to add to that README anything to help >>>>> describe the results. >>>>> >>>>> >>>>> https://github.com/django/channels/blob/master/loadtesting/2016-09-06/README.rst >>>>> >>>>> >>>>> Robert Roskam >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at https://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/f58727ac-fc47-439b-8943-eddf4021a96f%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
