To address the points so far: - I'm not yet sure whether "traditional" WSGI mode would actually run through the in memory backend or just be plugged in directly to the existing code path; it really depends on how much code would need to be moved around in either case. I'm pretty keen on keeping a raw-WSGI path around for performance/compatability reasons, and so we can hard fail if you try *any* channels use (right now the failure mode for trying to use channels with the wsgi emulation is silent failure)
- Streaming HTTP responses are already in the channels spec as chunked messages; you just keep sending response-style messages with a flag saying "there's more". - File uploads are more difficult, due to the nature of the worker model (you can't guarantee all the messages will go to the same worker). My current plan here is to revise the message spec to allow infinite size messages and make the channel backend handle chunking in the best way (write to shared disk, use lots of keys, etc), but if there are other suggestions I'm open. This would also let people return large http responses without having to worry about size limits. - Alternative serialisation formats will be looked into; it's up to the channel backend what to use, I just chose JSON as our previous research into this at work showed that it was actually the fastest overall due to the fact it has a pure C implementation, but that's a year or two old. Whatever is chosen needs large support and forwards compatability, however. The message format is deliberately specified as JSON-capable structures (dicts, lists, strings) as it's assumed any serialisation format can handle this, and so it can be portable across backends. - I thought SCRIPT_NAME was basically unused by anyone these days, but hey, happy to be proved wrong. Do we have any usage numbers on it to know if we'd need it for a new standalone server to implement? It's really not hard to add it into the request format, just thought it was one of those CGI remnants we might finally be able to kill. Andrew On Thu, Dec 17, 2015 at 6:32 PM, Anssi Kääriäinen <[email protected]> wrote: > On Thursday, December 17, 2015, Carl Meyer <[email protected]> wrote: > >> Hi Andrew, > > >> - I share Mark's concern about the performance (latency, specifically) >> implications for projects that want to keep deploying old-style, given >> all the new serialization that would now be in the request path. I think >> some further discussion of this, with real benchmark numbers to refer >> to, is a prerequisite to considering Channels as a candidate for Django >> 1.10. To take a parallel from Python, Guido has always said that he >> won't consider removing the GIL unless it can be done without penalizing >> single-threaded code. If you think a different approach makes sense here >> (that is, that it's OK to penalize the simple cases in order to >> facilitate the less-simple ones), can you explain your reasons for that >> position? >> > > We would also need some form of streamed messages for streamed http > responses. > > Is it possible to handle old-style http the way it has always been handled? > > - Anssi > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > 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/CALMtK1Gz%3DaYMLyFW2da2C6Wo_-c_V2T_4p6K9eh0vwrKB91dKw%40mail.gmail.com > <https://groups.google.com/d/msgid/django-developers/CALMtK1Gz%3DaYMLyFW2da2C6Wo_-c_V2T_4p6K9eh0vwrKB91dKw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- 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 [email protected]. To post to this group, send email to [email protected]. 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/CAFwN1upm8N8tOhCdAgPEbYbBO6MU%2BmnEQ%3D%3Dp6EmW75%3DbNXHkfg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
