Hello, I'm a little late to the party, thanks for the big overview on this complex matter.
There are lots of thinks I still don't understand though, for example regarding "what it unlocks". What asyncio structures would allow to run several DB queries concurrently safely and easily, that can't be achieved with some threadpool-like mechanism in nowadays' cod ? Most importantly, I'm not getting why gevent/eventlet-style solutions are systematically being dismissed in favor of asyncio. And the more I read/talk about it, the less I understand what all that hype around asyncio is. This is a whole new language, which forces people to trashbin half of the Python ecosystem, and remake it with similar code but filled with incompatible async/await statements. For sure, having so obstrusive keywords everywhere can be handy when writing highly concurrent code without mutexes. But who writes highly concurrent code in webservers ? The very principle of webservers is imho precisely to never interfere with other requests, never modify process-global structures, and at worst delegate some heavy or concurrent tasks to some dedicated executor. Greenlet-style parallelism would bring long-running requests and high parallelism to Django without having to touch the bulk of the code code, just the I/O parts (DB connections...) ; and thread-local is already greenified by Gevent for exemple, according to docs. Why would it bring "much higher risk of race conditions and deadlocks without careful programming" ? Preemptive threads are much more dangerous than the implicit but deterministic context-switching which occurs when greenlets reach socket/disk/sleep operations, and yet race conditions seem to be the least of the problems of the huge majority of Django programmers. I'd love to be wrong, but I have the feeling that with a fraction of the work required by django-asyncio, it would be possible to greenify the whole of Django, fix lots of current limitations and corner-cases of gevent (lack of builtin executor to offload tasks to real threads, lack of support in python package X/Y/Z...), and without having to recode any of the "middle" parts of existing modules. How can we say "third-party support for this style of concurrency is much weaker", whereas through monkey-patching, about ANY python module (except those using blocking C extensions) can be used in a Gevent project ? Granted, I have little experience with Geven and Asyncio, but all experience feedbacks I've read so far mainly insist on minor limitations of greenlets, and on the fact that "people are mainly going with asyncio" (a self-fulfilling prophecy?). Considered the dramatic difference in workload between the two, I'd really love to understand what killer-features justify to go for the "recode everything" solution (or what greenlet limitations would be show-stoppers on the long term). Thanks in advance everyone for your feedback on this issue. regards, Pascal Chambon -- 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/605d78af-f24a-46eb-9cac-4ad75547b604%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
