Re: What's the best configuration for this setup?

From: Peter Marelas <>
Date: Sun, 24 Nov 1996 11:39:25 +1100 (EST)

I dont think it should be the function of the application.

Have a look at your core routers, they should provide you with the ability to
prioritise packets based on the function.

Thus, you wont be limiting the bandwidth used by squid, and you will be providing interactive TCP sessions with good responses.

A'la cisco.

priority-list 1 protocol ip low tcp 8080
priority-list 1 protocol ip low tcp nntp
priority-list 1 protocol ip high tcp telnet
priority-list 1 protocol ip high tcp www

Peter Marelas

On Sun, 24 Nov 1996, Dancer wrote:

> principle. However..
> Here's our situation. As an ISP, we started with a single 14k4 modem (at
> that time, it cost us many thousands of dollars, and was acceptable, even
> when shared among a large number of users. Of course, we didn't have the
> WWW then, either). Then we ramped up to a 64K link, then 128K, now 256K.
> At the same time 'infrastructure' bandwidth has been on the increase as
> well. From a measly 2Mbps, now to a lofty 6Mbps across the pacific, and as
> much as 8Mbps between cities.
> What we're now seeing (esp, with caching proxies, which we use
> _extensively_), is that each increase in bandwidth makes it more likely
> that a fast-delivering document (ie: from a fast site, or served from the
> upstream cache on the other side of our link) will flood the link,
> rendering other connections (non-proxied ftp, telnet, and even other http
> connections) well..the word 'shitty' comes to mind (It's okay kids, I'm an
> australian, and I used it in a complete sentence).
> Bearing that in mind, I wouldn't mind seeing a 'virtual partitioning' for
> squid bandwidth:
> Squid is told something like: 'max_bandwidth 44Kbps' and makes sure that it
> does not read more than 44kilobaud from document-fetches in any second
> (neighbours don't count towards this number. They're presumably free, being
> on the inside of the link we're trying to protect, we hope). Delivery of
> documents is unaffected (let them get their own limiters, for gosh sakes).
> Obviously, the specified marker will be exceeded as tcp queues fill up, but
> after that point it should hover roughly around the specified number.
> Not an ideal solution, but it wouldn't take much fiddling to get a number
> that serves well-enough. Or you can measure with a cron job...or maybe even
> reconfigure on the fly. Up to you, I guess...but without _something_ of
> this order, every improvement in 'visible' bandwidth (wether it be actual
> link widening, improvements in protocols, or caching technologies) actually
> impacts more and more heavily on the response times for other connections,
> during the duration of a request.
> Squid might not be the ideal vehicle to test-drive this sort of thing, but
> it's something to think about. Our current protocol family is doing the
> best it can, but I don't think it was ever envisioned what sort of weird
> shit we do with them today. I have high hopes that HTTP/1.1 and IPv6 will
> help, but I won't bet any body-parts just yet.
> (Cultural references: Yes, Australians really do swear. A lot. Over the
> last two-hundred years or so, casual verbal profanity has wormed it's way
> into our culture. I honestly can't think of any words at all that the
> 'average' australian would find offensive, or even notice in casual
> conversation. Yes, there are always more extreme people (a bell-curve has
> two ends, naturally) who find relatively inoffensive things shocking. I
> expect everyone knows a few of them. And, yes...Our head of state swore at
> the queen. Quite colourfully, and (I am told) strongly. And it was _at_
> her, as well as _to_ her, though he didn't even notice until someone
> pointed it out to him afterwards. Nor, I understand, did she take offense.
> It isn't the first time we've done it to them, nor will it be the last.
> Essentially, what I'm trying to say is: It's nearly 3am. I slip back into
> my natural, comfortable modes of communication at this sort of hour, and as
> such, I don't necessarily recheck everything I type to see if I might be
> offending someone of country/religion/gender/species/other [your category
> here]. My last such casual mailing list post (no stronger than this one)
> earned me a set of asbestos underwear for the - rather stronger - flame
> that I got in response. Sorry, guys. At this hour, brain-cells are at a
> premium, the censors are in bed.)
> ----------
> > From: Jonathan Larmour <>
> > To: Daniel O'Callaghan <>; Ross Wheeler
> <>
> > Cc: Francis Vidal <>;
> > Subject: Re: What's the best configuration for this setup?
> > Date: Saturday, November 23, 1996 12:50 AM
> >
> > At 23:11 22/11/96 +1100, Daniel O'Callaghan wrote:
> > >This was discussed on freebsd-hackers not so long ago. It is possible
> to
> > >bandwidth limit connections by a simple
> > >
> > >while () {
> > > read();
> > > sleep();
> > >}
> >
> > But won't TCP still fill up its receive queue as fast as it can? I
> suppose
> > you could _deliberately_ only read a certain number of bytes rather than
> > everything available to keep the queue nearly full.
> >
> > But anyway determining how much to wait for is very awkward indeed as you
> > have to know the physical bandwidth of the connection, which will change
> all
> > the time as use is shared. It would also probably lead to oscillating
> around
> > the correct value and for most people it is not acceptable for it to be
> > slower than it could be - any bandwidth determining step would need many
> Kb
> > before coming even close to an estimate.
> >
> > Just my 2p
> >
> > Jonathan L.
> > Origin IT Services Ltd., 323 Cambridge Science Park, Cambridge, England.
> > Tel: +44 (1223) 423355 Fax: +44 (1223) 420724 E-mail: guess...
> > -------[ Do not think that every sad-eyed woman has loved and lost...
> ]------
> > -----------------------[ she may have got him. -Anon
> ]-----------------------
> > These opinions are all my own fault.

The Fulcrum Consulting Group               Peter Marelas - Consultant
12/10-16 Queen St, Melbourne VIC 3000,Australia   Ph: +61-3-9621-2100
PGP Key -> finger  Fx: +61-3-9621-2724
Received on Sat Nov 23 1996 - 16:49:30 MST

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