Thank you both for the information! It sounds like there isn't any significant downside the increasing the number of waitress threads beyond the number of available CPU cores if we expect them to be I/O bound rather than CPU bound. Is that true?
I will investigate our nginx configuration; perhaps it's limiting the number of requests per client to the upstream server. Thanks for that tip. We're using SPDY 3.1 and I'm testing in Chrome, so I don't think the number of requests should be throttled by the client or by nginx on the WAN side (it should be one, persistent TCP connection). I haven't tried uWSGI, but I did try gunicorn and switched to using multiple processes instead of multiple threads. That doesn't seem to have changed the timings much, so I don't think we're blocking on the GIL. The last option is the database or SqlAlchemy; I have not ruled that out yet but I can write a script completely outside the context of the web server that makes similar requests and see how it performs. Thank you both again for the help. On Friday, March 11, 2016 at 2:44:24 PM UTC-8, Jonathan Vanasco wrote: > > > My theory is that if the threads get tied up with a few slow requests, > the server can no longer service the faster ones. > > That's usually the issue. It's compounded more when you don't pipe things > through something nginx, which can block resources on slow/dropped > connections. > > A few ideas come to mind: > > i'd take a look at your nginx config. there are options to throttle the > number of connections per client. (upstream and WAN) > your browser could also have a limit on requests as well, and the > keepalive implementation (if enabled on nginx) could be a factor. are you > sure they're being sent in parallel and not serial? > > it's possible that you're having issues with database blocking. > > it's also possible, though i doubt it, that you're running into issues > with the GIL. you could try using uwsgi to see if there is any difference. > > > -- You received this message because you are subscribed to the Google Groups "pylons-discuss" 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 https://groups.google.com/group/pylons-discuss. For more options, visit https://groups.google.com/d/optout.
