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Re: #158: Proxy-Connection and Keep-alive

From: Willy Tarreau <w@1wt.eu>
Date: Fri, 9 Dec 2011 08:14:36 +0100
To: Mark Nottingham <mnot@mnot.net>
Cc: Amos Jeffries <squid3@treenet.co.nz>, ietf-http-wg@w3.org
Message-ID: <20111209071436.GD32374@1wt.eu>
Hi Mark,

On Fri, Dec 09, 2011 at 04:27:22PM +1100, Mark Nottingham wrote:
> OK, one more go at this.
> 
> Willy, you said:
> 
> > I'm not asking to emit the Keep-alive header, rather just to suggest
> > clients to continue to emit "Connection: keep-alive" when they suspect
> > the proxy could be 1.0, as they're doing right now.
> 
> Understand that using Connection: keep-alive with 1.0 proxies is *precisely* the cause of the interoperability problems that led to the design of persistent connections in 1.1; because 1.0 proxies aren't required to remove the Connection: header (or what it refers to), this can result in hanging connections. 
> 
> While *most* proxies have upgraded to implement this, you cannot count on it; they aren't required to implement it in 1.0, and IME there are still some that don't. I know that the proxies that you (Willy and Amos) are implementing now don't have this problem currently, but we're concerned with the entire installed base of proxies, not just current products.

That's my point too. I think that both Amos and I are willing to change our
codes to satisfy the spec if some interoperability problems are spotted. Here
I was really talking about what I'm observing in field with deployed clients.

> So, suggesting that they do it is too strong; there are legitimate reasons to be concerned about interoperability in this use case, and we're all about the interoperability.
> 
> See below for another go at a proposal. Personally, I think this is as far as we can go; others may feel differently (in either direction), and are encouraged to say so (I'd like to get this one nailed down).
(...)

I'm fine with this one. What's important to me is that we give at least a
clue to implementers about what issue they might face, so that they consider
some real-world tests and possibly some fallbacks for embarrassing situations.
Your version also suggests that it's better to avoid doing this when not
necessary, which is good if we want to achieve a global cleanup. Works for me.

Thanks,
Willy
Received on Friday, 9 December 2011 07:15:39 GMT

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