Re: [squid-users] Want to monitor squid, by pulling an image which is local.

On 27/05/11 10:05, Tory M Blue wrote:
> Hiya :)
>
> I would like to have via the primary squid instance a method to grab a
> local image, to verify that squid is up and running.
>
> I have F5's that I want to add a monitor, if the squid box goes down,
> take it out of the vip.. However I can't have the monitor query the
> squid box and have it pull an image from the cache_peer, since we at
> times take those down for maintenance, and I much rather have squid
> serve old content, than not be available at all.

Seems to be some confusion.

  Stale vs non-stale content is a matter for the website cache control
HTTP headers. Squid *will* serve stale content according to RFC 2616.

  Proxy up/down merely determines how much lag the client gets exposed
to as unavailable peers get contacted for data.

A peer is unavailable if either its box is down OR you manually dropped
it out. It can't be available while shutdown, for instance.

Now why does the Squid box being up/down matter independently of Squid
itself?

>
> So I'm trying to figure out, how I can put a static image on the squid
> box itself,which allows me to pull that image through the standard
> port, standard squid process.

Squid has a set of icons which it loads for FTP directory listings etc.
They are configured in the /etc/squid/mime.conf configuration file.

If you need a test image loaded by Squid the URL
http://$host/squid-internal-static/icons/unknown.gif
should come back from squid-2 with a question-mark icon.

NP: $host is the public FQDN host name for your Squid box. As determined
by the visible_hostname directive.

>
> monitorurl doesn't quite do it, since I'm looking for a test from a
> 3rd party device.

monitorurl takes any URL you want *through* the cache_peer link. If it
comes back okay the peer is assumed to be accessible and ready to accept
traffic.

Amos

-- 
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   Current Stable Squid 2.7.STABLE9 or 3.1.12
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