[plug] Mirrors

[Anthony J. Breeds-Taurima]

On Fri, 14 Feb 2003, James Elliott wrote:

> How do mirrors work (not the glass ones but the ones we download from)?
> 
> I gather the major downloads are not only stored on the source server but
> also on "mirrors" in other countries.
> 
> 1.  Since we pay no more for Internet use if we download from within
> Australia as distinct from overseas, why use mirrors? - what is the
> advantage?

The first reason mirroring happend was becuase there was more than one person
in a given institute that wanted access to something.  so It was downloaded
once onto the local network and everyone that wanted it got it.  It was purely
financial.  Now days mirroring is still driven by cost factors BUT it also
has the huge advantage of reduceing load (CPU and Network) on the master
servers.  Imagine the size of machine required if _all_ debian users had to
update from 1 server eeeek.

Australia (and a few other countires) is in the ugly position of having to
pay much more for data that comes in externally.  Hence the mirror.aarnet.edu
project.

> 2.  Who pays for the mirror sites if the downloads are free?

That depends on exactly where the data comes from.  BUT probably it is the
first Austalian host for the data.

comsider:
1) ftp.debian.org
2) ftp.au.debian.org
3) ftp.wa.au.debian.org  (WAIX)

I want to create debian.cantech.net.au.

If I mirror from site 1 I pay the cost as I'm pulling the data fom OS
If I mirror from site 2 Then again I pay BUT less as the data is "australian"
If I mirror from site 3 then I get it for free :)

Now, If you move up the scale ie pretend I'm now "ftp.wa.au.debian.org"

If I mirror from site 1 I pay the cost as I'm pulling the data fom OS
If I mirror from site 2 Then again I pay BUT less as the data is "australian"
Of course it is possible that there is a peering exchange on this level.

etc etc.  So the untimat cost centre varies.

HTH

Note, I don't speak for any site listed here, and I have no knowledge of
there business arrangements.

Yours Tony.

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