RE: [squid-users] SNMP which object?

From: Palmer J.D.F. <>
Date: Tue, 27 Mar 2001 14:30:52 +0100

* Have you considered using the proxy.pac autoconfigure script?

Yes, I do use a proxy.pac file, unfortunately we have the whole spectrum of
browsers here at the Uni and some including Netscape 6 won't support it. I
agree that this would be easier.

Rebuilding the DNS isn't really that much of a pain, the script does
everything for us and emails any errors to us.

Configuring everyone's browser is a different story, fortunately 80% of our
users log into Novell 4 or 5 so I have created an application object which
is ran every time they log in, this sets various things including the
browser cache settings. Once again easy with IE but a pain with Netscape.
The other 20% well... It'll be alright. I have created some web based
instructions to follow, which depending on the load that It'll create we may
put a redirect to them on the router.

In the near future all http traffic and possibly ftp will be denied by our
gateway router unless it has come from one of our caches, this saves us 50K
a year on transatlantic traffic, as our cache uses the national JANET cache
as a peer. This will require everyone not logging into Novell to alter
their cache settings.

With respect to load on the server, it copes very well it has only died once
from anything other than a dodgy HDD in the last 6 months. However we're
getting a shiny new Sun Ultra 10 to replace the Intel box as the main cache.
It currently gets around 2.1 million requests per day, and a hit rate of 46%
- 50%.


Jezz Palmer

Jezz Palmer.
Internet Systems Officer.
Library and Information Services
University of Wales, Swansea
Singleton Park
Tel 01792 513260

 -----Original Message-----
From: Edmund Haworth []
Sent: 27 March 2001 13:41
To: Palmer J.D.F.;
Subject: RE: [squid-users] SNMP which object?

Hash: SHA1

Have you considered using the proxy.pac autoconfigure script?

once the server dies, it'll back up onto a differant proxy server,
this wouldn't fix your inital problem of monitoring the proxy server
it's self, but it would avoid rebuilding DNS tables everytime it
died. the other problem would be 3000 PCs all connecting to one web
server may be a bad idea, and reconfiguration of browsers might be
fun too.

just a thought, might help?

Edmund Haworth
Assistant Network Engineer
Worcester College of Technology
Worcs WR1 2JF

Tel: +44 1905 725516
Fax: +44 1905 28906

- -----Original Message-----
From: Palmer J.D.F. []
Sent: 27 March 2001 12:51
To: ''
Subject: [squid-users] SNMP which object?


I have SNMP running on my squid servers and am monitoring them with
What I would like to do now is to use SNMP to detect whether the
process has stopped responding for whatever reason.

At present I have a cron job which pings my main cache every 2 mins,
there is no response, the DNS tables are rebuilt re-assigning to the IP address of the backup cache. The main
is continually pinged until it is back up again, at this point the
tables are rebuilt again. Hence redirecting http traffic back
through the
main cache server.

The reason we were using ping was because we had an intermittent
fault which was the cause of 99% of crashes, this caused a kernel
panic and
therefore the network card would stop responding to ping. However
this HW
fault has been fixed and ping is no longer suitable for this type of
monitoring as squid/something else may die but ping still responds.

As we force nearly 3000 PC's through the cache, it is imperative that
problems are detected and the caches switched ASAP, as users are
unable to
access external sites whilst the cache is down.

I am going to use SNMP from now on to detect squid fatalities, but
I'd like
to know which SNMP objects I should use to base my testing on.

If anyone has any thought on this I'd be grateful

Many thanks,

Jezz Palmer.

Jezz Palmer.
Internet Systems Officer.
Library and Information Services
University of Wales, Swansea
Singleton Park
Tel 01792 513260

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Received on Tue Mar 27 2001 - 06:30:07 MST

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