Musings

Hi all,

We've been putting a bit of thought into some things here, and I'd like to
bounce a couple of ideas out to some more knowledgable people :)

Basically, many of our clients are complaining that certain sites aren't
being refreshed, and it appears the problem may be in Netscpae and IE's
cacheing system - even when they hit reload, the pages seem to come from
the cache, not from the proxy server. However, this discussion started
with the assumption that it was the proxy server that was at fault (it may
be in a different way, but that's something else altogether).

The default squid.conf sets the expiry time for pages to 3 days. If this
default is lowered drastically, say to 12 hours, we're trying to predict
what the results would be. As far as we can work out, it's going to
depend on the makeup of the requests. If the cache is made up primarily
of pages that are hit by many people (eg. msn.com), then this would mean a
small number of pages would be refreshed 6 times as often, generating not
too much extra traffic (and it's primarily our inbound traffic that I'm
looking at here), and a lot of pages that are access say once every couple
of days would no longer be cached
(no big deal if they're only being accessed every couple of days anyway).

On the other hand, if the cache is made up of lots of pages that are hit
once a day only, then we're going to loose most of the cache, and most of
the benefit of the server.

What we're missing is some sort of stat indicating the makeup of the cache
- a minimum hit, maximum hit, average hit per page, and a standard
deviation over the pages would be real nice in this regard. What would it
take to get these figures?

Oh, one other question: As stated above, we're having problems with
Netscape's cache holding pages. It seems (to my untrained eye) like
netscape asks the cache for a last-modified, checks it, and decides to
serve up it's local copy instead of requesting it from the proxy server.
If it requested the page, it would get the up-to-date one, but it doesn't.
 Bar disabling the disk cache (which is not really practical for dial-up
users), is there any way to get squid to recognise these requests and pass
them on, or am I barking up the wrong tree?

KevinL

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Kevin Littlejohn                                     darius@wantree.com.au
Wantree Development                                       tel:    481 4433
Perth, Western Australia 6000                             fax:    481 0393
"Hours of frustration punctuated by moments of sheer terror" - a.s.r.