Re: HTTP/2.0 Magic

[Willy Tarreau <[e-mail]>]

On Tue, Feb 19, 2013 at 05:24:02PM +1100, Mark Nottingham wrote:
> > However, I remember that when the same approach was proposed on hybi, one
> > of the concerns that was raised was that some servers will happily return
> > a valid response and may corrupt intermediary caches. I remember that about
> > all intermediary implementations authors explained that no cache will ignore
> > the method in the request, but still that was a concern that plagued the
> > design.
> 
> I'm not convinced it's a concern.

I'm convinced it's not. But I mentionned this so that we get prepared
to see such comments come back again.

> > We should absolutely not have a "banner protocol".
> 
> Definitely not; question is whether the server prepends something to the
> start of the framing layer.

I'm only seeing two valid reasons for prepending something :
  1) if the frame encoding is compact enough to use all bits and make
     an HTTP/1 response look like a possibly valid frame which the
     client must parse, we'd prefer to avoid this useless work ;
  2) if the frame can be tailored to look like an HTTP/1 response,
     we'd prefer to avoid the possibility that this is triggered from
     the client.

So maybe something looking like an HTTP/1 error may be useful then
(eg: "HTTP/1.0 505 V2ONLY CRLF CRLF").

Willy