[squid-users] Re: refresh_pattern question

On Wed, 23 Dec 2009 16:34:37 -0800
Manjusha Maddala <mmaddala25_at_nextag.com> wrote:

> >From "Squid - the definitive guide", a simplified description of the
> refresh_pattern algorithm is:
>
> - The response is stale if the response age is greater than the
> refresh_pattern max value.
> - The response is fresh if the LM-factor is less than the
> refresh_pattern percent value.
> - The response is fresh if the response age is less than the
> refresh_pattern min value.
> - Otherwise, the response is stale.
>
> The webserver I have neither sends a Last-modified header nor an
> Expires header.

That's odd, if you don't have Last-Modified, or an equivalent header,
you shouldn't see TCP_REFRESH_MISS. Does it have a cache-control header
instead of Expires?

Are you sure you aren't hitting a previous refresh_pattern line?

 
> > >From squid.conf,
> > > refresh_pattern . 21600 100% 21600 override-expire
> > >
> > > That is, a cached page is fresh if its age in cache < 15 days
> > > (21600=15*24*60).
> >
> >
> > not quite, an object without an explicit expiry time, but that
> > can be validated, could be stale in less than 15 days.
> >
>
> So, won't all pages with response age < 15 be considered fresh?

If an object lacks explicit expiry information and can be validated,
it's governed by the percentage and max-age only, and is stale if either
is exceeded e.g. a object that was last-modified 5 days ago and
validated 3 days ago will have exceeded your 100% limit.
Received on Thu Dec 24 2009 - 02:11:28 MST