Re: Some general SPDY feedback / questions

On 07/08/2012, at 10:58 AM, Poul-Henning Kamp <> wrote:

> In message <>, Mark Nottingham wri
> tes:
>> I'd characterise expect/continue as being on the lighter borders of a 
>> grey area; it is used, but it does cause interop problems.  
>> [...]
>> I'd be interested to hear comments from others, of course.
> Expect/continue should not be allowed in HTTP/2.0, it is a transport
> flow-control mechanism and it does not work.

No, it's an application flow control mechanism, not transport. I.e., your transport layer (TCP) doesn't do anything with it; neither does the transfer layer (HTTP). It's used by the application itself to determine if a request should be sent -- the semantics are surfaced, visible and used by it.

> My strawman for how to do it in HTTP/2.0:
> The client can have no more than one TCP connection with six
> outstanding requests, each with no more than 8KB of headers+body
> in total, until the server sends an explicit message increasing its
> allowance, either in stand-alone message if we have a control
> channel, or as part of a response.
> All numbers are examples subject to improvement.
> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk@FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe    
> Never attribute to malice what can adequately be explained by incompetence.

Mark Nottingham

Received on Tuesday, 7 August 2012 16:01:01 UTC