Subject: Re: [P2Prg] RE: DNS and P2P

From: Lucas Gonze <[email-masked]>
Date: Mon, 8 Sep 2003 01:36:06 +0200

Three comments on P2P and DNS --

First, some of the Chord folks published a paper on the topic.  If my 
memory is right, they found was that misconfigured servers are so 
common that the root servers perform most lookups, and so the DNS 
network as a whole acts like a hub and spoke network.  Since hub and 
spoke is hard to beat in many ways, they were skeptical about any P2P 
design at all, since even a perfect O(log N) can't compete.

Second, administration of the namespace is not so easy, even if names 
are long numbers instead of human friendly text.  Long term maintenance 
of a well known public key has to include replacement with a new key 
from time to time, and key replacement is currently defined in an ad 
hoc way that doesn't inspire faith.  That's not to say that it's 
undoable, but that so far as I know current solutions all involve a 
*lot* of hand waving.

Third, it's best to start with usecases.  What shortcomings of DNS do 
you want to fix?

It seems to me that a better angle of attack on the problem of P2P 
naming is to forget about DNS.  I'd attack a new namespace with looser 
application requirements, like instant messaging.

- Lucas Gonze

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From: Bill Yeager <[email-masked]>
Date: Fri, 19 Sep 2003 11:12:38 -0700 (PDT)

| Since hub and 
| spoke is hard to beat in many ways, they were skeptical about any P2P 
| design at all, since even a perfect O(log N) can't compete

This is assuming you do a lookup across the entire N-peer space. I like the
jxta approach of using rendezvous for lookup. What is missing there is an
hierarchy which I also think is a good idea for a global P2P Internet.

I don't think it is a question of using the current system, and yes, there are
huge performance problems. You can find lots of papers on that with Google.

Right, it is difficult to beat a centralized service if 

	o) You can register everything in some way. Not likely with billions of
	peer nodes out there in configurations we haven't even begun to imagine.

	My guess is ad-hoc registration (probably indexed) and across super-peers is
something to think about.

	Remember, in you own home you might have a single super-peer to manage
your "virtual home network," and also securely attach you to the Internet.

	o) The lookups get processed in a timely way

	o) The service cannot be spoofed as DNS currently can be.

On the other hand, one does not wish to scrap a system that has been working
so well since what, 1981. We need to ask how it might evolve to meet P2P
requirements. If it cannot, then we start over, and do a little research.

Bill

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From: [email-masked]
Date: Thu, 25 Sep 2003 19:08:05 +0900

Lucas, 

Little bit an old topic but I suppose your point is important for
the wg.

At Mon, 8 Sep 2003 01:36:06 +0200,
Lucas Gonze wrote:
(snip)
> application requirements, like instant messaging.

Could you tell me a bit more about your plan on the namespace
and its implementation? I have my requirements here...;

 1. make it free to use new namespace for application
 2. application can control namespace confliction;
     name-to-resource; one-to-one, many-to-one, one-to-many,
		       many-to-many, or combination of them.
 3. user's shouldn't see its 'raw-form' like UUID in their eyes.
    might have aliases(mnemonics?) with it
 4. can deal with denial of service (e.g. inserting junks everywhere
    or on a key)

My worries is also on implementation. Considering a simple DHT, 
I can think of some suffix/prefix approach for requirement 1.
Requirement 3 is application dependent. But with such a simple
DHT, I don't know how to deal with 2 and 4. Puzzle-auction is
a simple way for requirement 4, but that makes micronodes very
unhappy :-(

Yusuke

<offtopic>
Now is the time to agree on a namespace free from wildcard-invation, 
isn't it? :-)
</offtopic>

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From: Bill Yeager <[email-masked]>
Date: Thu, 25 Sep 2003 16:05:11 -0700 (PDT)

| <offtopic>
| Now is the time to agree on a namespace free from wildcard-invation, 
| isn't it? :-)
| </offtopic>

Good point. To easy to attack. Find "*". We even had to modify the IMAP list
command because early versions of  - LIST "/" "*" - would do the unfortunate
obvious thing on a unix server. 

I know that Jxta has very minimal support for wild card lookup. They set a
hard upper limit (3?) for the return values.

Finally, it is worth looking at the Jxta SRDI (Shared Resource Distributed
Index) for those who invision super-peer centric p2p networks. The current
implementation is very responsive.

http://platform.jxta.org/java/workinprogress/srdi.html

Bill

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From: Lucas Gonze <[email-masked]>
Date: Sat, 27 Sep 2003 15:36:20 -0400

> Little bit an old topic but I suppose your point is important for

But maybe on topic for a special interest group...

>  4. can deal with denial of service (e.g. inserting junks everywhere

I'd nominate "lightweight infrastrure" as the biggest requirement.  The 
infrastructure to run a DNS namespace is far too heavyweight for many 
applications.  Among other absurdities, intermingled DNS and OS code.

To do a good job with this conversation means working out usecases, 
though.

> Now is the time to agree on a namespace free from wildcard-invation,

Those guys handed it to us on a silver plate with that one.  Thank you, 
Verisign.  :)

- Lucas

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From: [email-masked]
Date: Mon, 29 Sep 2003 20:45:06 +0900

Lucas, 

One clarification please. You mention lightweight is the best
and DNS is heavy and bad, as I understood.

From my point of view, DNS itself is simple enough. Some DNS folks
said 70% of load on root NS is from some wrong implementations thus
they could be eliminated if we _all_ do the right thing. The issues on
DNS I think are bad implementation and namespace management that can
never be free from (political) conflict.

What the point you consider as the key factor of weight?

Yusuke

At Sat, 27 Sep 2003 15:36:20 -0400,

---

From: Lucas Gonze <[email-masked]>
Date: Mon, 29 Sep 2003 10:52:39 -0400

Hi Yusuke,

What strikes me as heavyweight about DNS is not the protocol but rather 
the cost of administering a root with a level of robustness comparable 
to any shipping P2P network.  I'm not saying it's expensive to run name 
server, I'm saying it's expensive to run a name server with robustness 
no worse than the entire network.  The comparison here is not between 
web servers and name servers, but between the entire web and The Root 
That Art in Reston.

- Lucas