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Re: sunsite.org.uk - rsync access to cd-images



Jason Gunthorpe <jgg@ualberta.ca> writes:

> On 3 Aug 1999, Philip Hands wrote:
> 
> > Last time we released new CD images, the traffic spike generated by
> > Sunsite UK was so great that JANET's London backbone was brought to
> > its knees, and they pulled the plug on Imperial College for a few
> > days, which is why Sunsite went off the air after the release.  They
> > have 622Mbits IIRC, so throwing more bandwidth at the problem probably
> > won't help.
> 
> A single 'normal' machine (and even an extrodinary one would need a heck
> of alot of clients) is not going to saturate 622Mbit, something else was
> happening there.

Sunsite UK isn't a ``normal'' machine :-) It's something like an 8
processor Sparc, with stupid amounts of memory (you can check it out
when they get HTTP back up).  As I heard it, they didn't saturate
their ATM, they saturated JANET in London, and JANET took defensive
measures.

> samosa itself has demonstrated 60G/day of traffic, that's
> around 60 people downloading CD images per day. (most leaches will
> probably only grab one of the images too..)

That may be true in theory, but in practice you get quite a few people
doing partial downloads, and then retrying, which burns a lot of your
bandwidth.  When the 2.0 images were released, Netcom UK were giving
me 10Mbit, and open.hands.com ended up being their second (not by
much) largest consumer of International bandwidth, which is why we had
to introduce the passwords in the first place, since the alternative
was to be thrown off the network.  The depressing thing was that a
significant chunk of that was from repeated failed attempts from
places like Hong Kong, which is a stupid waste of two lots of
international bandwidth.

It might make sense to move the cdimage.d.o label to another machine
whilst keeping the master images on open, so that cdimage.debian.org
actually points at one of our mirrors.  Keeping the master images in
the UK seems to make sense because Steve and I are both here.

Moving the CNAME would allow us to give people access to the images on
that machine without impacting other mirrors' access to the images on
open.

The only down side is that if you make it too easy to get the images,
you get lots of clueless ones who should be using APT, downloading CD
images instead, and then mailing me saying ``what do I do now?''.

Given that I still get quite a few of those, despite all the ``Don't
do it!'' stuff on the web pages, making access easier may not actually
serve the common good.

> > It would be great if you could provide us with another high bandwidth
> > mirror though, especially if its on the other side of the Atlantic.
> 
> Now that we have the resources avaiable it would be nice to put the master
> server onto one of Debian's machines - it ultimately becomes more
> maintainable - you have been and still are doing a great job, so it's no
> big deal...

Oh, fair enough.  I'd always considered open.hands.com to effectively
be a Debian machine (that's the primary reason I put it on the
Internet, and is also the reason I get the bandwidth for free from my
ISP) but I guess for that to be completely true it would need to be
administered, or at least administrable, by the debian-admins ?

Would allowing the debian-admins root access deal with your concerns?
I'd probably want to be included in debian-admins if that were the
case, but presumably that would make sense anyway, so I could get a
better feel for what they might be tempted to do on open (since I'd
rather do it myself if I'm around)

BTW several of the CD build crew already have accounts on open, and
I'm happy to give any Debian developer an account.  Also Steve
McIntyre has root access.

Cheers, Phil.


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