Re: [squid-users] Custom max-age header

I know it's nasty, but I've been thinking for a while about a
refresh_pattern option that would write the new, overridden freshness
(e.g., assuming your'e using override-expires, LM factor, etc.) into
outgoing response cache-control.

On 27/10/2009, at 1:47 PM, Amos Jeffries wrote:

> On Thu, 22 Oct 2009 11:24:50 +0200, Struzik Wojciech <bm9ib2r5_at_gmail.com
> >
> wrote:
>>> You have not yet answered the question of:
>>> WHY are you even thinking this ??
>>
>> Because one of my backend is Amazon S3 and I can't set up
>> Cache-Control on it. So I looking for different solution how to
>> change
>> this header field (squid). I want the objects to be cache as long as
>> possible on the clients web-browser side (1 year).
>>
>
> Eww. Nasty.
> FWIW; any dynamic page language should be able to set them per-page.
>
> There is no way to insert values into Cache-Control: while retaining
> any
> other settings there. But if Squid is built to allow HTTP violations
> you
> might use header_access to strip out the Cache-Control: header
> entirely and
> header_replace add a new version of your own when one is stripped
> out (I'm
> not sure of the behavior if there was none to begin with).
>
> This is *very* risky, since it only allows one flat CC value
> regardless of
> the content.
>
> Amos
>
>>
>>
>> On Wed, Oct 21, 2009 at 1:52 PM, Amos Jeffries <squid3_at_treenet.co.nz>
>> wrote:
>>> Struzik Wojciech wrote:
>>>>
>>>> Actually I'm using varnish but varnish is unstable (slowdowns,
>>>> coredumps). Varnish supports Cache-Control, so I can set up this on
>>>> it.
>>>> Here is a part of network my topology
>>>>
>>>> nginx (consistent hash) -> varnish
>>>> ---> 1st backend
>>>> |
>>>> |
>>>> |
>>>> ---> 2nd backend
>>>> |
>>>> |
>>>> -> varnish ---> 1st backend
>>>>
>
>>>> |
>>>>
>>>> ---> 2nd backend
>>>>
>>>>
>>>> I want replace varnish into squid (better stability/performance
>>>> when
>>>> one of backends is down), so I wonder where is better to add
>>>> Cache-Control: max-age header, on nginx or squid. Is it possible to
>>>> set up custom Cache-Control (max-age) on squid ???
>>>
>>> You have not yet answered the question of:
>>> WHY are you even thinking this ??
>>>
>>> It's only possible to do it reliably and securely on the originating
> web
>>> server. Squid does not make it easy to grossly violate the HTTP
>>> protocol.
>>>
>>> There are three levels of Cache-Control values:
>>> s-max-age applying to middleware proxies
>>> max-age applying to web browsers (and middleware only if there is no
>>> s-max-age present)
>>>
>>> The Surrogate-Control header is also available on latest 3.1 via
>>> ESI to
>>> control middleware in the delegated reverse-proxy chain separate
>>> to the
>>> s-max-age values for external middleware.
>>> It should not be to hard to make it work for HTTP reverse-proxy
>>> situations.
>>>
>>> Amos
>>>
>>>>
>>>> On Wed, Oct 21, 2009 at 11:40 AM, Matus UHLAR - fantomas
>>>> <uhlar_at_fantomas.sk> wrote:
>>>>>
>>>>> On 21.10.09 10:48, Struzik Wojciech wrote:
>>>>>>
>>>>>> I using Squid 2.7. How can i add custom field max-age to
> Cache-Control
>>>>>> response header ???
>>>>>
>>>>> why would you want to do that on squid?
>>>>> --
>>>>> Matus UHLAR - fantomas, uhlar_at_fantomas.sk ; http://
>>>>> www.fantomas.sk/
>>>>> Warning: I wish NOT to receive e-mail advertising to this address.
>>>>> Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu
>>>>> postu.
>>>>> BSE = Mad Cow Desease ... BSA = Mad Software Producents Desease
>>>
>>>
>>> --
>>> Please be using
>>> Current Stable Squid 2.7.STABLE7 or 3.0.STABLE19
>>> Current Beta Squid 3.1.0.14
>>>

--
Mark Nottingham       mnot_at_yahoo-inc.com