Re: [squid-users] min-fresh / max-stale not working?

When someone contributes the work or funds development.

Adrian

2008/9/4 Markus Karg <karg_at_quipsy.de>:
> Is there a plan when HTTP/1.1 completely will be supported in all sides?
> I mean, I hardly can't believe it -- HTTP/1.1 was specified in 2008. Why
> waiting so long?
>
> Thanks
> Markus
>
>> -----Original Message-----
>> From: Amos Jeffries [mailto:squid3_at_treenet.co.nz]
>> Sent: Mittwoch, 3. September 2008 15:40
>> To: Markus Karg
>> Cc: squid-users_at_squid-cache.org
>> Subject: Re: [squid-users] min-fresh / max-stale not working?
>>
>> Markus Karg wrote:
>> > Sorry it was a typo. The test was done mit SQUID-2.7-STABLE4
>> actually.
>> > The HTTP/1.1-Support is only experimental???
>>
>> Brand new in 2.7 and some bugs still being found.
>> It's also only on one side of Squid, the one which links to Servers
>> IIRC, so the client-facing code is still HTTP/1.0-only.
>>
>> Amos
>>
>> >
>> >> -----Original Message-----
>> >> From: Amos Jeffries [mailto:squid3_at_treenet.co.nz]
>> >> Sent: Mittwoch, 3. September 2008 07:14
>> >> To: Markus Karg
>> >> Cc: squid-users_at_squid-cache.org
>> >> Subject: Re: [squid-users] min-fresh / max-stale not working?
>> >>
>> >>> Dear SQUID Community,
>> >>>
>> >>> it seems as if SQUID is not dealing correctly with "min-fresh" and
>> >>> "max-stale":
>> >>>
>> >>> Currently we are evaluating the use of SQUID-2.6-STABLE4. It all
>> >> seems
>> >>> to work pretty well, but just "min-fresh" and "max-stale" is not
>> >>> working. Our client agent wants to guarantee to get data that is
>> >> fresh
>> >>> for a specific amount of time. So we provide "min-fresh=3500" and
>> >>> "max-stale=0". To verify SQUID's behaviour we have programmed an
>> >> origin
>> >>> server the always responds with some static headers and entity
>> data,
>> >> and
>> >>> a client that requests exactly that information, via SQUID as a
>> >> proxy.
>> >>> The client uses the Cache-Control header with a min-fresh=3500 and
>> >>> max-stale=0 value, and the server is always sending data with a
>> >>> max-age=3600 value. But the client gets from SQUID a 200 OK
>> response
>> >>> having max-age=3600 and Age=502! So, the current age of 502 plus
>> the
>> >>> desired min-fresh of 3500 is 4002, minus the max-stale of 0 still
>> is
>> >>> 4002, what is much more than the max-age of 3600 -- so the request
>> >>> cannot be satisfied without a warning, since the response will not
>> > be
>> >>> fresh long enough! So we expect to get at least a Warning header.
>> > But
>> >>> there is none! It looks like SQUID just ignores the min-fresh=3500
>> >> and
>> >>> max-stale=0 headers!
>> >>>
>> >>> The HTTP/1.1 specification says:
>> >>> 13.1.2 Warnings
>> >>> Whenever a cache returns a response that is neither first-hand nor
>> >>> "fresh enough" (in the sense of condition 2 in section 13.1.1), it
>> >> MUST
>> >>> attach a warning to that effect, using a Warning general-header.
>> >>> also it says:
>> >>> 13.1.1 Cache Correctness
>> >>> If a stored response is not "fresh enough" by the most restrictive
>> >>> freshness requirement of both the client and the origin server, in
>> >>> carefully considered circumstances the cache MAY still return the
>> >>> response with the appropriate Warning header.
>> >>>
>> >>> In the default case, this means it meets the least restrictive
>> >> freshness
>> >>> requirement of the client, origin server, and cache (see section
>> >> 14.9)
>> >>> So for me it looks as if SQUID is buggy, since it does not add the
>> >>> mandatory Warning header. Can that be true? Or do I have to enable
>> >> some
>> >>> switch like "HTTP/1.1-Compliance = YES"?
>> >> Squid 2.6 is HTTP/1.0 only. For any HTTP/1.1 stuff you will need
>> > Squid
>> >> 2.7 and its experimental support.
>> >>
>> >> As for the cache controls, someone more knowledgeable will
> hopefully
>> >> speak
>> >> up.
>> >>
>> >> Amos
>> >
>>
>>
>> --
>> Please use Squid 2.7.STABLE4 or 3.0.STABLE8
>
>
Received on Thu Sep 04 2008 - 00:26:57 MDT