Re: Squid problem?

On Wed, 30 Jul 1997, Jonathan Larmour wrote:

> At 14:52 30/07/97 +0100, Leigh Porter wrote:
> >I just tried a www site that has multiple IP addresses.
> >

> > I try the site form machine A and find it works fine, then from machine
> > B, an IE4 thing with WinNT 4 the sire returns server busy (on a
> > differant IP
> > address).
> >
> > I click reload on this system and I get server busy again even though
> > on another system, putting that IP address in gives the page OK - the
> > Squid box had cached the server busy page!
>
> Look at the negative_ttl entry in squid.conf. Setting this to 0 will
> prevent all negative caching. Setting it to 1 minute is probably more
> sensible (its unlikely to suddenly start working in a matter of seconds).

My strong suspicion is that this is not a negative_ttl situation, given
the way in which the round-robin IP cache access works in the default
Squid.

I think that machine A got the first IP address in the list, which was of
a machine that was accepting connections, then machine B got the second IP
address, of a host that was too busy to return the page and thus refused
the connection, then the reload happened to hit another busy server -- the
third address in the list, and then when the IP address was given, that
particular server happened to be less loaded and was able to accept the
connection.

For instance, the www.msnbc.com site in my IP cache has eleven addresses,
four of which are currently marked bad. I guess that's what you get for
running a web server on NT -- you need a dozen multiprocessor machines
to do the work of one... ;-)

        -Mike Pelletier.
Received on Wed Jul 30 1997 - 09:07:16 MDT