Re: Clarification on HTTP caching (RFC 7234)

Hi Will,


> On 29 Apr 2015, at 4:37 am, Will Sargent <will.sargent@gmail.com> wrote:
> 
> Hi all,
> 
> I have some questions on the behavior of RFC 7234's s-maxage response directive -- it looks like the behavior for s-maxage response directive differs significantly from maxage in that a max-age response directive means that a stale response calls for "validate", where the behavior is "validate, but serve stale on a timeout or (if stale-if-error is defined) on a 5xx".

Yes.

> Meanwhile, s-maxage says " The s-maxage directive also implies the semantics of the proxy-revalidate response directive."  Well, proxy-revalidate is the same as must-revalidate, but only operating on shared caches, and the validation behavior there is "validate or 503 on timeout".

Yes. 
> So the question is: the behavior of s-maxage explicitly to timeout rather than give a stale response?  I've been looking around the internets, and I don't see this behavior mentioned in the blogs or even in the O'Reilly Web Caching book or HTTP The Definitive Guide.

Yes - see <http://httpwg.github.io/specs/rfc7234.html#serving.stale.responses>

> P.S.  I'm also confused as to what the difference between a "disconnect' and a "timeout" is -- in one area, a disconnect is referred to as "cannot reach the origin server" and in the warning it's referred to as "intentionally disconnected", but there's no direct reference to it.

Following up separately.

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

Received on Wednesday, 29 April 2015 00:16:35 UTC