Re: p1: Upgrade ordering (possible HTTP/2 impact)

[Mark Nottingham <[e-mail]>]

WFM

On 23/04/2013, at 6:12 PM, Willy Tarreau <[e-mail]> wrote:

> Hi Mark,
> 
> On Tue, Apr 23, 2013 at 05:38:59PM +1000, Mark Nottingham wrote:
>> Proposal - add to p1 6.7:
>> 
>> """
>> When occurring in a request, Upgrade's value indicate the protocol(s) the
>> client would like to upgrade to, in order of relative preference. When
>> occurring in a 101 (Switching Protocols) response, there will usually only be
>> one protocol indicated in Upgrade. When occurring in any other response,
>> Upgrade indicates the protocol(s) the server is capable of upgrading to, in
>> order of relative preference.
>> """
> 
> I'm OK in the principle, though I think this should be fused into existing
> text, probably that way :
> 
>   The "Upgrade" header field is intended to provide a simple mechanism
>   for transitioning from HTTP/1.1 to some other protocol on the same
>   connection.  A client MAY send a list of protocols in order of relative
>   preference in the Upgrade header field of a request to invite the server
>   to switch to one or more of those protocols before sending the final
>   response.  A server MUST send an Upgrade header field in 101 (Switching
>   Protocols) responses to indicate which protocol(s) are being switched
>   to, and MUST send it in 426 (Upgrade Required) responses to indicate
>   acceptable protocols in order of relative preference.  A server MAY
>   send an Upgrade header field in any other response to indicate that
>   they might be willing to upgrade to one of the specified protocols for
>   a future request, in order of relative preference.
> 
> Willy
> 

--
Mark Nottingham   http://www.mnot.net/