[squid-users] Question about refresh_pattern and access time...

[Amos Jeffries]

On 12/10/17 04:57, EdouardM wrote:
> Hi All,
> question i have in mind about the refresh_pattern and multi-access...
> let say i use a refresh_pattern about 1 month with an already cached object,
> the question is:
> - scenario 1: whatever the number of times the object will be requested,
> once the delay (1 month) is expired the Squid will download a fresh copy
> from internet ?
> - scenario 2: each time the object is requested the ending-date will be
> re-calculated for +1 month ?
> 
> in both scenarii, the remote object never changes...
> from your point of view, what's the correct scenario here ?

Neither of those.

HTTP defines an algorithm for calculating object freshness.
<https://tools.ietf.org/html/rfc7234#section-4.2>

What refresh_pattern does is provide default values for the 
section-4.2.2 parameters *if* the server does not deliver the values itself.

The most recent releases of Squid can also infer Date or Last-Modified 
from message arrival times for the age calculation algorithm.

Amos