Re: Auto-bypassing a parent when parent is down

From: Matthew J. Probst <>
Date: Fri, 22 May 1998 09:49:17 -0600 (MDT)

On Thu, 21 May 1998, Duane Wessels wrote:

> Dancer writes:
> >The problem, Duane, is that in many cases the costs of bandwidth coming
> >off proxy servers is much reduced. Therefore, site setups want to
> >absolutely forbid squid to fetch directly for ANY reason whatsoever
> >_unless_ the parent(s) should go down, not be reachable etc.

This is exactly what we want.

> inside_firewall is still not the right configuration to use.
> Firewall means you can not ever make direct connections.
> The right way to fix this is for you to tell me when does Squid
> make direct connections and the parents are alive?

Yes, I have been able to configure squid to bypass a parent when it goes
down, But I'm never able to get squid (on its own) to recognize that the
parent has come back up.

> Determining up/down status of neighbor caches is just guesswork,
> and you will always be able to find a situation where Squid
> guesses wrong. I think its better to err on the side of caution
> and go direct so the user gets the page, rather than return
> an error page.

Is it really all guesswork? I'd be happy with the simple test of: If
squid is un-able to connect to its parent's port in X number of seconds,
it starts grabbing pages directly. Then if Y seconds have passed since we
switched to direct mode, we switch back to going through the parent.

If the parent timesout again, the cycle will repeat and wait another Y
seconds before trying to go through the parent.

I know that simply connecting to a port does not necessarily mean the
parent is up and running, but I'm satisfied with it anyway.

I'll go ahead and try the patch.

Received on Fri May 22 1998 - 08:53:20 MDT

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