Re: [squid-users] refresh_pattern explanation wanted

On Thu, 26 May 2005, Matus UHLAR - fantomas wrote:

> # usage: refresh_pattern [-i] regex min percent max [options]
> [...]
> # 'Percent' is a percentage of the objects age (time since last
> # modification age) an object without explicit expiry time
> # will be considered fresh.
>
> percent of what time? percens of "max" time? or does it mean thar lm-factor
> thing below? (should be mentioned in the default manual imho)

Age of the document. Yes this is the origin of the lm-factor.

The authoriative manual on Squid directives is squid.conf.default.

> # Basically a cached object is:
> #
> # FRESH if expires < now, else STALE
> ^^^^^^^^^^^^^
> shouldn't that be "expires > now"? an object is fresh, if it will expire in
> the future, not if it already expired, right? (a bug in the doc?)

Right.

> another strange thing: the lm-factor is explained on
> http://www.squid-cache.org/Doc/FAQ/FAQ-12.html#ss12.20
>
> # OBJ_DATE is the time when the object was given out by the origin server.
> This is taken from the HTTP Date reply header.
> # OBJ_LASTMOD is the time when the object was last modified, given by the
> HTTP Last-Modified reply header.
>
> # OBJ_AGE is how much the object has aged since it was retrieved:
>
> OBJ_AGE = NOW - OBJ_DATE
>
> - It it really calculated from current local date, and Date: from object
> header? Does squid mix local Date and remote servers' Date or is this part
> of configuration incorrect and squid counts current local date and locatl
> date when the object was fetched?

Yes there is an mix. And is why it is importand time on the web servers
and your proxy is reasonably correct. This is even more visible in the
Expires header.

Regards
Henrik
Received on Fri May 27 2005 - 00:10:56 MDT