httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Eric Covener" <>
Subject Re: HTTP Protocol: How frequently should browser repeat requests after 304 responses?
Date Wed, 17 Sep 2008 20:51:59 GMT
On Wed, Sep 17, 2008 at 4:46 PM, Manik Taneja <> wrote:
> this behavior seems highly browser dependent.  There may be a few
> possibilities as to why the browser doesn't send an IMS request.
> a. the browser cache is cleared
> b. the browser has a limited size cache and so this object gets ejected due
> to lack of space. you could try increasing the size of the browser cache and
> see if that helps.
> c. the browser prolly follows some algorithm where by it decides to send an
> IMS only once, unlikely, but I am just guessing.
> d. the browser is IE and is buggy :).

I think in Dan's case the problem is that the IMS validation never
gives the opportunity for a "new" expires time to be communicated to
the client:

0) Browser gets a 200 responds for a static file along with an Expires header
1) the browser happily uses it's local copy during the Expires window
2) Expires time is up
3) browsers sends a request with IMS
4) server responds with a 304
5) It would sure be nice if the browser had some way to find a new
Expires: time, because now every subsequent request for the static
file is a round-trip to get the 304.

Is there any room in HTTP/1.1 for the client or server to save on the
round-trips after the revalidation?

Eric Covener

View raw message