Re: [squid-users] negative_ttl vs. an Expires header -- which should win?

Mark Nottingham wrote:
> What version of Squid are you using?
>
> This changed somewhat in 2.7; IIRC in 2.6 negative_ttl overrides
> response freshness, whereas in 2.7 response freshness (i.e., expires or
> cache-control) has precedence.
>
> Cheers,
>
>
>
>
> On 02/10/2008, at 3:56 PM, Gordon Mohr wrote:
>
>> Using 2.6.14-1ubuntu2 in an reverse/accelerator setup.
>>
>> My backend/parent is by design setting explicit 'Expires' headers 1
>> day into the future, even on 404/403/302 response codes.
>>
>> I'm seeing the 4XX responses later served as TCP_NEGATIVE_HITs, which
>> is good.
>>
>> It appears, from my testing, that they are sometimes cached a bit
>> longer than 'negative_ttl', but they are not cached as long as the
>> Expires header suggests, even with plentiful cache space.
>>
>> What is the designed intent of Squid -- should the 'negative_ttl' or
>> the Expires header be definitive?
>>
>> - Gordon @ IA
>
> --
> Mark Nottingham mnot_at_yahoo-inc.com
>
>

negative_ttl wins.
It should be set to "0 seconds" in any case to retain HTTP standards.
This has been fixed in recent squid releases, though older squid
contains a bad default of more than 0.

Amos

-- 
Please use Squid 2.7.STABLE4 or 3.0.STABLE9