Subject: Re: [p2pi] New version of the problem statement

From: "Anthony Bryan" <[email-masked]>
Date: Thu, 3 Jul 2008 00:38:00 -0400

On Wed, Jul 2, 2008 at 3:55 AM, Enrico Marocco
<[email-masked]> wrote:
> (I keep cc'ing Vijay, who is running the ALTO BoF with me and is
> certainly interested in this)

Sorry, I accidentally did not reply all before.

> I think this is a very interesting discussion, I'd suggest to move it on
> the ALTO mailing list (more info at http://alto.tilab.com).

Ok, I've added it in & here's my initial message so people can follow along:

Metalink is an XML format for describing downloads and how to get
files. Usually this is lists of mirrors, way to get files over P2P,
checksums, digital signatures, and other metadata. It's supported by
about 30 applications, mostly download managers, web browsers, FTP
clients, & P2P clients. See http://en.wikipedia.org/wiki/Metalink for
more info.

For instance, we allow for geographical location and priority for
sources to be listed (like in section 3.5 of your document).

      <url type="ftp" location="us"
preference="90">ftp://ftp.example.com/example.ext</url>
      <url type="ftp" location="uk"
preference="90">ftp://ftp.example.net/example.ext</url>
      <url type="http" location="us"
preference="90">http://example.com/example.ext</url>
      <url type="http" location="de"
preference="90">http://example.net/example.ext</url>
      <url type="bittorrent"
preference="100">http://example.org/example.ext.torrent</url>

> Anthony Bryan wrote:
>> Great. ALTO seems like the type of thing we would include in
>> Metalinks, it's all just information that clients might use. For
>> instance, some P2P apps support exporting/importing .metalinks - where
>> someone might want to share specific versions of a document. They
>> could contain the hashes that identify those specific files and how to
>> get them specifically from that person.
>
> Actually I was seeing it the other way around.  ALTO is supposed to be a
> service to help users select the best sources for a given content
> according to their needs. It was initially thought for peer selection in
> file-sharing application, but could be also used, for example, for
> finding the closest mirror.
>
> If I understood it correctly, Metalink's information is related to the
> content only (i.e. two different users accessing the same content use
> identical Metalink files) while ALTO information is specific to the
> querying user (i.e. two identical queries from users in different
> locations generate different responses).  What seems a reasonable
> scenario is: 1. the user finds Metalink information for the content he
> wants to get, 2. modifies such information according to his needs and
> preferences (e.g. expands BitTorrent entries with current peers), 3.
> sends such information to an ALTO service, together with his network
> location information (his IP address or whatever kind of geolocation
> information he is able to gather), 4. the ALTO service returns such
> information with priority values modified according to user's network
> location. Would this make sense?

Yes, makes sense from what I understand. This is your domain so, if
you think it fits the bill I will support it :)

Most Metalink files are identical but some producers like MirrorBrain,
which powers openSUSE downloads, create downloader specific Metalink
files catered to a person's geographical location.

http://www.mirrorbrain.org/

-- 
(( Anthony Bryan ... Metalink [ http://www.metalinker.org ]
 )) Easier, More Reliable, Self Healing Downloads
_______________________________________________
p2pi mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/p2pi

---

From: Enrico Marocco <[email-masked]>
Date: Fri, 4 Jul 2008 17:09:46 +0200

> http://www.mirrorbrain.org/

The ApacheCon presentation is enlightening, it makes me wonder if anyone
has ever thought about a generic Metalink customizer.

Also, do you think that an extension for indicating peers sharing actual
content pieces nested in ed2k and bittorrent URIs would fit in Metalink
overall design? According to me, that would make it look pretty much
like a possible solution for ALTO.

-- 
Ciao,
Enrico

---

From: "Anthony Bryan" <[email-masked]>
Date: Fri, 4 Jul 2008 12:14:13 -0400

> has ever thought about a generic Metalink customizer.

Yes, it is a great presentation, isn't it? Those interested can find
it here: http://www.mirrorbrain.org/presentations

What do you mean by generic customizer? Do you mean besides
country/priority information for resources?

The current apps for creating Metalinks are listed at
http://www.metalinker.org/implementation.html#generate . Besides
MirrorBrain, there is Geo McFly which is an on the fly generator of
metalinks based on client's geographical location.

> like a possible solution for ALTO.

We crave extensions and I think that would fit. :)

Currently, there are no Metalink clients that support ed2k but there
are 5 that support BitTorrent. I would recommend consulting the
authors of aria2 (command line, cross platform, open source), KGet
(GUI, open source), and Retriever (GUI, cross platform, closed
source). I'm guessing that because of the open source & responsive
nature of the aria2 project, you could get a demo up & running in no
time.
-- 
(( Anthony Bryan ... Metalink [ http://www.metalinker.org ]
 )) Easier, More Reliable, Self Healing Downloads
_______________________________________________
p2pi mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/p2pi

---

From: Enrico Marocco <[email-masked]>
Date: Fri, 4 Jul 2008 19:19:50 +0200

> country/priority information for resources?

I was thinking of sort of a service which arranges priorities in
submitted Metalink files according to the location of the querying host,
the finer granularity, the better. I guess this is something similar to
what Geo McFly does.