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Re: On the abuse of chunking for interactive usages

From: Poul-Henning Kamp <phk@phk.freebsd.dk>
Date: Tue, 10 May 2011 21:45:16 +0000
To: Willy Tarreau <w@1wt.eu>
cc: HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <4816.1305063916@critter.freebsd.dk>
In message <20110510212615.GA504@1wt.eu>, Willy Tarreau writes:

>My concern comes from this specific use of chunking. I see no reason why
>this would be valid. I know it will not work at many places. Some proxies
>(such as nginx IIRC) buffer the complete request before passing it on.

Well, it doesn't say anywhere in RFC2616 that "A server SHALL NOT
reply until it has received the entire request including the body,
if any.", so from a standards point of view, it is not "invalid".

But we can readily agree that it will probably come as a major
surprise to most readers of RFC2616 that anybody would do this.

And most HTTP proxies (as opposed to HTTP load-balancers) will
not permit it through at all.

You can configure Varnish to let this through:  Varnish has a
"pipe" mode, where after the first request on a TCP connection has
been passed to the backend, varnish just moves bytes forth and back.

But that is merely a reflection of my "code, not policy" attitude
to software tools, I agree with you that this should be discouraged
as much as possible.


Poul-Henning

-- 
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.
Received on Tuesday, 10 May 2011 21:45:40 GMT

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