Re: p1: Via and gateways

Willy Tarreau <w@1wt.eu> Sat, 20 April 2013 07:26 UTC

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Date: Sat, 20 Apr 2013 09:25:09 +0200
From: Willy Tarreau <w@1wt.eu>
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Subject: Re: p1: Via and gateways
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On Sat, Apr 20, 2013 at 12:21:52AM -0700, David Morris wrote:
> 
> 
> On Sat, 20 Apr 2013, Mark Nottingham wrote:
> 
> > 
> > p1 Section 2.3 says:
> > 
> > > However, an HTTP-to-HTTP gateway that wishes to interoperate with
> > > third-party HTTP servers must conform to HTTP user agent requirements
> > > on the gateway's inbound connection and must implement the Connection
> > > (Section 6.1) and Via (Section 5.7.1) header fields for both
> > > connections.
> > 
> > This means that accelerators and CDNs MUST generate a Via header on the
> > outbound connection. This isn't widely practiced, and I'm not sure it's
> > necessary. Comments?
> 
> I don't care about MUST, but I think the Via header can be useful for
> problem determination. A smart content server could also adjust for
> a detected accelerator and/or transcoder ... perhaps by avoiding
> optimizations dependant on a direct connection and byte/byte transfer
> between the client and the server.
> 
> So I'm very much in favor of keeping the Via: header.

OK but Mark is not discussing about removing it but keeping the MUST
since a number of existing products already don't add it and will not
for some of the reasons mentionned in this thread.

So I think that based on your feedback this MUST should be turned into
a SHOULD.

Willy