Easier ISO downloads for users

[Anthony Bryan]

On 2/9/07, Francois Petillon <fantec at proxad.net> wrote:
> Anthony Bryan wrote:
> Metalinks collect information about files in an XML format used by
> programs that download. The information includes mirror lists, ways to
> retrieve the file on P2P networks, checksums for verifying and
> correcting downloads, operating system, language, and other details.
> With a list of multiple ways to download a file, programs can switch
> to another server if one goes down. Or a file can be downloaded from
> many mirrors at once, usually making the download go much faster.
> Downloads can be repaired during transfer for guaranteed downloads
> with no errors. Geographically closer mirrors can be used before
> others further away. Downloads can be filtered by a file's operating
> system or language. They can also be used to add multiple files to a
> transfer queue. All this makes things automatic which are usually not
> possible or at least difficult, and increases efficiency,
> availability, and reliability over regular download links.>
>
> Hello again... :-)

Hi Francois, a pleasure to hear from you again. :) Thanks again for
your help in improving metalink with constructive suggestions.

> As usual, I will remind you that doing segmented downloads is not
> creating free bandwidth but it only allow one user to steal bandwidth
> (or server ressources) from other users. Thus once everyone use this
> kind of tools, you simply won't have more bandwidth than before but as
> servers will have to manage many more connections on smaller transfer
> size, you are likely to get degraded bandwidth.
>
> Moreover, as usually servers set a maximum number of simultaneous
> allowed connections, using more connnections will increase the risk to
> fill up this number and to block others users connections.
>
> Last and for all previous reasons, some admins will disable needed
> commands to resume downloads. On the server I manage, when an IP was
> allowed to open up to 4 connections, 30% of users were using 60% of
> server ressources...

Thanks for bringing this up! These are all excellent reasons for using
metalink - by putting your preferences into a machine readable format
that courteous users can take advantage of. (Along with configuring a
server correctly and to your liking).

Metalink isn't focused on segmented downloading, although many of the
clients do support that, some of them don't. The increased
availability from multiple links, integrity/reliability from
checksums, being able to add multiple files to a transfer queue and
other automated features are also found useful by others.

Ubuntu, OpenOffice.org, or other organizations can choose to limit (in
the metalink, according to the spec) the number of connections used
for downloading a file, or for specific servers. That is, you can say
in the metalink that you don't want programs doing segmented
downloading, or restrict them to a certain number of connections to a
server. Of course, servers still need to be correctly configured
because, as you say, other programs will not respect your wishes and
use up resources.

-- 
(( Anthony Bryan
  )) Metalink [ http://www.metalinker.org ]