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Re: Problems with caching header values

From: Wilfred Nilsen <wilfred.nilsen@cox.net>
Date: Sun, 24 Aug 2003 19:20:35 -0700
Message-ID: <001a01c36aaf$7a700a90$6401a8c0@windogs>
To: <ietf-http-wg@w3.org>


> Keep in mind that caches aren't obliged to cache when headers allow
it;
> they may have strategies that they believe work better.
>
> In my experience, browser caches are pretty simplistic, and very
> conservative. They may have the images inheriting freshness
information
> from the page they're referenced from, or they may interpret the
> refresh tag as a forced refresh for everything on the page.
>

I believe you are right.  I did a few tests and it seems that a
browser sends a new GET request if you press the reload button and
that includes all images in the page, which seems to inherit the
refresh from the page.  Looks like the browser always bypasses the
cache when the reload button is pressed, no matter the content of any
cache headers.  I presume that a page with a "meta refresh" tag
behaves as if the reload button was pressed.

Thank you Mark, Robert and Alex for your comments.

/Wilfred



> Cheers,
>
>
> On Thursday, August 21, 2003, at 02:30  PM, Wilfred Nilsen wrote:
>
> >
> > I have a page that is generated dynamically and I therefore set
the
> > "Cache-Control: No-Cache" header. The page contains a meta refresh
tag
> > and is automatically polled every so often.
> >
> > The page contains links to images that never change so in order to
> > prevent the browser from attempting to fetch new versions of the
> > images, I set the header value "Cache-Control: max-age=86400". The
> > problem is that the browsers I have tested this with, IE 6.0 and
> > Mozilla 1.13, seems to ignore the max-age header value and are
always
> > checking for newer versions. The browsers are set to get a new
page
> > when the current page is out of date.
> >
> > I also tried to set the "Expires" header but that did not help
either.
> >
> > Thanks,
> > Wilfred
> >
>
>
Received on Sunday, 24 August 2003 22:17:37 GMT

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