Re: [squid-users] Re: Help on Refresh Pattern options

So, if an object as an LM of, lets say, 3 days ago and it's "new" on my cache...
How does a %50 percent option work?
Will it be "fresh" for one and a half day?

Sorry, but I'll need a dummy explanation 'cause I don't get it.

On 10/30/07, RW <fbsd06@mlists.homeunix.com> wrote:
> On Wed, 31 Oct 2007 12:31:39 +1300 (NZDT)
> "Amos Jeffries" <squid3@treenet.co.nz> wrote:
>
> > > Hi there:
> > > I'm having some problems understanding how the refresh_pattern
> > > options works.
> > > The Squid guide says:
> > >
> > >
> > > FRESH if expires < now, else STALE
> > > STALE if age > max
> > > FRESH if lm-factor < percent, else STALE
> > > FRESH if age < min
> > > else STALE
> > >
> > > Min:
> > > time (in minutes), an object without an explicit expire time should
> > > be considered fresh.
> > >
> > > Percent:
> > > percentage of the objects age (time since last modification age) an
> > > object without explicit expire time will be considered fresh.
> > >
> > > Max:
> > > upper limit on how long objects without an explicit expiry time will
> > > be considered fresh.
> > >
> > >
> > > So, my question is this; if the object's age is between Min and Max,
> > > is it STALE or FRESH?
> >
> > That logic says STALE (!<min ... choosing else).
>
> No it doesn't, you have to follow the pseudocode through until you get a
> STALE/FRESH result, and then stop. If you can compute an lm-factor,
> then the "age < min" line can't be reached.
>
> Objects without an LM time cannot be refreshed, they have to be
> refetched; without a min setting such objects would not be cached at
> all.
>
> > IMHO, Max is there because max-age (given by server) CAN be less than
> > min (configured).
>
> "max" is ignored if the server supplies an expiry time, it's there to
> provide an upper-limit to how long a object can be kept fresh by its
> lm-factor.
>
> There are basically three classes of object:
>
> 1. with explicit expiry information (max/min/percent are ignored)
>
> 2. with LM, but no expiry - governed by percent and max.
>
> 3 with neither - governed by min
>
>
>
> ( Note that all of the above assumes that no refresh rule override
> options have been set.)
>
>
>
>
>
Received on Fri Nov 02 2007 - 07:30:45 MDT