Re: Strange Behaviour of cache....

robert@psy.uq.edu.au writes:

>
>I'm relataively new to Squid but have been delving around in the config and
>with the debug levels and am not sure how to interpret the following from
>the logfile:
>
>853395764.468 11861 130.102.32.104 TCP_REFRESH_HIT/304 103 GET
>http://www.habs.com/scores/9697/schedule.htm -
>FIRST_PARENT_MISS/http-proxy.uq.edu.au -
>
>
> The object http://www.habs.com/scores/9697/schedule.htm was stale,
>so an If-Modified-Since was sent. The 304 code means that it has not been
>modified since. The TCP_REFRESH_HIT means that although it was stale it
>was in the local cache...so my big question is....why did my cache request
>the object from my parent who actually returned a MISS? Am I correct in
>interpreting this as meaning that while I got a REFRESH_HIT and a 304 Not
>Modified that my cache STILL retrieved the object from my parent who retrieved
 
>it from the original site?? I originally thought, "no, that can't be right,
>if I get a HIT and a 304 then I will deliver immediately from MY cache" but
>the delivery time of 11861 points more to my cache waiting on my parent to
>retrieve a copy and then pass it along to me.

Yes, your cache asked the parent for the object. But neither retrieved
the whole object because the origin server sent 'Not Modified'.
All caches in the request chain preserve the 'If-Modified-Since' header.

Your parent cache did not retrieve the whole object, and then decide that
your copy was not modified.

> Another quick query, how can I adjust the LRU time? When I was
>playing with debug levels I saw that LRU was being applied with a 2.94 day
>time limit. Ideally I'd like to tweak the parameters so that when someone
>downloads the latest netscape.exe or whatever that it stays in the cache
>for at least a week before being purged.

You can set 'referenge_age'.

Duane W.
Received on Fri Jan 31 1997 - 11:00:10 MST