Re: Squid config

On Fri, 25 Apr 1997, Don Joy wrote:
> Ok, i am using version "Squid Cache: Version 1.1.beta16". Lets see if i
> understand this.
First, upgrade to squid-1.1.10.

> If i use the default line in the shipped version of:
> refresh_pattern . 0 20% 4320
> Then a cached entry that was created 10 hours ago and accessed 5 hours
> ago would evaluate like this:
>
> if (CLIENT_MAX_AGE)
> if (AGE > CLIENT_MAX_AGE)
> return STALE
> if (AGE <= MIN_AGE)
> return FRESH
> if (EXPIRES) {
> if (EXPIRES <= NOW)
> return STALE
> else
> return FRESH
> }
> if (AGE > MAX_AGE)
> return STALE
> if (LM_FACTOR < PERCENT)
> return FRESH
> return STALE
>
> if (CLIENT_MAX_AGE)
> if (600 > 4320)
> return STALE
No, you are wrong. You mix CLIENT_MAX_AGE and MAX_AGE. Look at the Release
Notes again.

> if (600 <= 0)
> return FRESH
> if (EXPIRES) {
> if (EXPIRES <= NOW)
> return STALE
> else
> return FRESH
> }
> if (10 > 4320)
> return STALE
Wrong again. MAX_AGE is given in minutes, so if looks like:
      if (600 > 4320)
          return STALE
        
> if (2 < 20)
> return FRESH
> return STALE
Wrong again! If a cached entry was created 10 hours ago, the object has
earlier date in the Last-Modified header than in the Date header (which
reflects the time at the generation of the cacheable response).
So, consider a page which was modified 100 hours before it was cached.
Then LM_FACTOR = AGE / LM_AGE = 0.1 which means 10% in this case
      if (10% < 20%)
          return FRESH

Bertold

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 Kolics, Bertold E-Mail: bertold@tohotom.vein.hu
 University of Veszprem, Hungary W3: http://tohotom.vein.hu/~bertold/
 Information Engineering Course
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Received on Sun Apr 27 1997 - 03:22:30 MDT