Re: ftp1.us.debian.org and FTP mirrors
On Thu, Oct 22, 1998 at 09:58:33AM -0500, email@example.com wrote:
> | Look at my netselect package, which chooses the "fastest" server from an
> | arbitrary set of supplied names. I designed it exactly for this. Version
> | 0.2 actually works. It merely needs to be integrated into APT somehow...
> Without looking at the package and how it works I want to make a few
> comments. I think this whole idea of choosing a mirror that is close
> and fast is a great idea. However the code must take into account that
> a majority of people may not have dedicated net connections, real dns
> host names or even be connected when they install.
Thanks to Jules, I think he answered this nicely...
> One approach would be to use the timezone information to pick an
> appropriate mirror. Of course the timezone of the mirror would have to be
> stored in the mirror info.
It's a _totally_ ugly myth that geography has anything to do with net
performance. In Canada, for example, almost everything goes through the
U.S. at some point because they have a more complete/redundant/fast Internet
backbone than we do. That means that although I'm in Waterloo, Ontario,
talking to a server in Toronto (an hour away by car) can often be a _lot_
slower than one in Seattle (far away).
And some net links are really loaded down -- ftp.de.debian.org is faster for
me than some U.S. sites. I realize that using transatlantic links for
this stuff is wasteful... luckily most U.S. sites are faster for me than
Germany is :)
Furthermore, with a cable modem, it becomes increasingly important (and
difficult) to find the "fastest" server. The difference between 20k/sec and
200k/sec is a big one.
Netselect takes all this into account, using a heuristic based on the number
of hops, packet loss, and average ping times. It does several things at
once so it can go through a long list of servers in a short time.
> Wasn't Jason working on a new Package file format for the mirror list.
I think so. Last I checked, it was missing a lot of mirrors including two
of the fastest for me (ftp.cdrom.com and debian.crosslink.net). As far as I
know, there's also no useful conversion script for it yet... (to make it
into a sources.list file after passing it through netselect).