[ILUG] Making squid work

[Niall O Broin]

On Sat, Oct 06, 2001 at 11:36:52AM -0400, Wesley Darlington wrote:

> Apols for even mentioning this but is your computer's time correct?

You're forgiven :-) but it's close enough - within one minute of my cesium
clock's display.

> Sure. It's extremely vanilla: http://www.yelsew.com/squid.conf.gz 
> Also, as I mentioned, possibly not useful for your squid version. :-(

Yeah, I had a look at it - nothing strange or startling in there.

> Is your cache full? Big enough?

Not specified -> default of 8M/100M.

> Sample tail from access.log with big cache:
> 1002381682.518     12 10.0.1.17 TCP_MEM_HIT/200 6161 GET http://graphics.userfriendly.org/images/uf_greek.gif - NONE/- image/gif
> 1002381682.521      2 10.0.1.17 TCP_MEM_HIT/200 4678 GET http://graphics.userfriendly.org/images/uf_chinese_gb.gif - NONE/- image/gif
> 1002381682.531      9 10.0.1.17 TCP_MEM_HIT/200 5127 GET http://graphics.userfriendly.org/images/uf_linuxnews_pl.gif - NONE/- image/gif

Exactly what I'd expect to see i.e. squid is returning the objects from its
cache (memory in this case, as you'd just repeated my test). 

And now it gets curioser and curioser. I decided to RTFM (I know, all was
not yet lost, but still.) Actually I located and read the FAQ (which for
some bizarre reason the Squid people apparently won't allow distributions
distribute) and there I read that  TCP_CLIENT_REFRESH_MISS  means

] The client issued a "no-cache" pragma, or some analogous cache control
] command along with the request. Thus, the cache has to refetch the object.

Reasonable enough, except why the hell would Netscape do that ? I'm running
NS 4.77 here, just because SuSE updated my 4.76 in the distribution update,
so I wondered if it was buggy - a buggy Netscape - what a surprise :-) I
shifted my backside one chair south and used Netscape 4.76 on my notebook
and bingo - fetched everything from the squid cache just as expected,
verified both by the response and by the access log lines with

192.168.1.103 TCP_MEM_HIT/200

So I gave Netscape 4.77 a fair trial and rpm -e'ed it at sundown (yeah, I
know, it's sunup, but I was in a hurry). Popped in my SuSE 7.1 DVD,
reinstalled Netscape 4.76 and - oops rpm -e'ed an innocent program :-(

Same game, I'm afraid. Some further investigation showed that the acces log
lines had

127.0.0.1 TCP_CLIENT_REFRESH_MISS/200

i.e. the localhost IP address rather than the machines address in my HAN.
This seemed to be due to my using localhost as the proxy hostname. I changed
this to 192.168.1.101 but it's still the same except now I have

192.168.1.101 TCP_CLIENT_REFRESH_MISS/200

in access.log.

So, what gives ? For some reason beyond my ken squid believes that every
request from a Netscape running on my local machine 'issued a "no-cache"
pragma, or some analogous cache control command along with the request'.

Well, I certainly didn't ask it to :-)

It does seem to be to do with Netscape, though. I just set my http_proxy
appropriately and did

lynx -dump http://graphics.userfriendly.org/images/uf_greek.gif > uf_greek.gif

and got the prompt back immediately and there was a corresponding line with

192.168.1.101 TCP_MEM_HIT/200

in access.log. So why does Netscape, on the same box as squid, hate me ?




Niall




> Sample tail from access.log, tiny cache:
> 1002382360.936    598 10.0.1.17 TCP_MISS/200 5635 GET http://graphics.userfriendly.org/images/slovenia.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382360.948    703 10.0.1.17 TCP_MISS/200 6267 GET http://graphics.userfriendly.org/images/linmag_dutch.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382361.244    600 10.0.1.17 TCP_MISS/200 6160 GET http://graphics.userfriendly.org/images/uf_greek.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382361.357   1103 10.0.1.17 TCP_MISS/200 9090 GET http://m.tribalfusion.com/media/10606.gif - DIRECT/m.tribalfusion.com image/gif
> 1002382361.581    637 10.0.1.17 TCP_MISS/200 4760 GET http://graphics.userfriendly.org/images/anvandarvanligt.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382361.604    656 10.0.1.17 TCP_MISS/200 6322 GET http://graphics.userfriendly.org/images/brugervenlig.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382361.847    489 10.0.1.17 TCP_MISS/200 2895 GET http://graphics.userfriendly.org/images/brukervennlig.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382361.966    717 10.0.1.17 TCP_MISS/200 5706 GET http://graphics.userfriendly.org/images/bf-logo.jpg - DIRECT/graphics.userfriendly.org image/jpeg
> 1002382362.282    677 10.0.1.17 TCP_MISS/200 3208 GET http://graphics.userfriendly.org/images/tv2_dk.gif - DIRECT/graphics.userfriendly.org image/gif
> 1002382362.334    753 10.0.1.17 TCP_MISS/200 5126 GET http://graphics.userfriendly.org/images/uf_linuxnews_pl.gif - DIRECT/graphics.userfriendly.org image/gif
> 
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