Re: Direct as last resort

On Fri, 30 Jul 1999, Clifton Royston wrote:

> > We have several sibling and two parent caches.
> > We want the siblings to have priority over the parents
> > We want the parents to have priority over direct
> > We want to go direct if the parents have failed.
> >
> > Why? Cost issues. It is significantly cheaper to go via our uplinks
> > caches than go direct, however I want to go direct should their
> > caches fail (I don't want the support calls).
> >
> > Currently if we use ICP to manage this, the parent caches -always-
> > win (they're slightly closer and our siblings don't have the same
> > links we do) so that voids the whole point of having peers.
>
> Dumb question here: why wouldn't you *want* this to be the case? If
> the parents end up responding faster to ICP, they're probably going to
> deliver the hits faster too. Isn't that what you want?

Unfortunately, here in Oz, Internet traffic is generally charged per meg,
not by pipe size, so while this may be marginally faster, I'm sure what
hes trying to use is like this:

Siblings - $ 0.00 per meg, or next to (local peering networks)
Parents - $ 0.16 per meg, + or - a bit (upstream providers caches)
Direct - $ 0.23 per meg, + or - a bit (upstream direct)

> It may be technically sweet to have a fully distributed network with
> load going off to the siblings, but if the parents serve the hits
> better, it would seem to me you ought to just let Squid use them. The
> sibs would still be useful in that they'd end up picking up hits if the
> parents were saturated or down for some reason.

Its more a pure cash question I think, When you start pulling large
amounts of traffic then using 0, 16 and 23c traffic as appropriate becomes
more of an issue ;-)

It would be good to be able to balance parent/siblings more, except i'd
like to go sibling, direct, then parent, but ONLY querying the parents
when direct fails (just to throw another worm in the can ;-).

Simon Lindsay simon@iweb.net.au
Technical Manager Icq. 1485568
The Internet Company Pty. Ltd. http://www.iweb.net.au/~simon
InterWeb Connections and Portal.net Ph. (08) 8221 5444
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Received on Sat Jul 31 1999 - 01:09:27 MDT