[ogsa-wg] Teleconference minutes - 9 November 2005

[Maguire_Tom at emc.com]

So is OGSA-Naming suggesting that the agreed upon algorithm for uniqueness
in time and space is RFC4122?  

There are several well known issues with UUIDs that should be considered.
The general algorithm uses the Mac address (in fact the algorithm piggy
backs on the uniqueness of the mac address and adds a timestamp component
for uniqueness over and above the mac addr).  There have been a number of
discussions about privacy and the UUID/GUID algorithms w.r.t mac addresses.
Additionally, as the authors themselves point out in RFC4122 there are
circumstances where duplicates may occur; failure of a node and restart,
migration of network card to another machine. 
There is also no way to ensure that a UUID is 'valid'.
Also please be careful; if you ever need to resolve a UUID to a reference it
will be next to impossible.  
So in short, I think there are considerable technical issues with UUIDs. 

 
I will point out that the general pattern that UUIDs use is:
1) Base uniqueness by some body handling registration (IEEE does this for
mac addresses)
2) Agreed upon algorithms or encoding schemes for spatial uniqueness within
the uniqueness provided by point 1

This is not terribly different from URI pattern:
1) Base uniqueness by IANA for domain names
2) Agreed upon encoding scheme for pathing after base

The not so subtle difference is that you can resolve a URI....

Tom 

-----Original Message-----
From: owner-ogsa-wg at ggf.org [mailto:owner-ogsa-wg at ggf.org] On Behalf Of Mark
McKeown
Sent: Monday, November 14, 2005 8:53 AM
To: Andreas Savva
Cc: 'ogsa-wg'
Subject: Re: [ogsa-wg] Teleconference minutes - 9 November 2005


A comment on the minutes...

"* Naming Policy discussion

  Tom sent out the naming policy proposal to the list before the
  call. Briefly it states that OGSA fellow WG specifications must
  return EPRs. The EPRs may be decorated with more information but
  there should be no normative statement in the specifications that
  that information must be present.

  One technical issue is the level of coordination required for
  mandating WS-Names. The main point being the difficulty of
  quaranteeing uniqueness-in-space-and-time. For the uniqueness
  statement to be true an algorithm to create a unique string must be
  specified and everyone must agree to use it, which introduces a new
  set of problems."

Is this technical issue not addressed by IETF RFC 4122, "A Universally
Unique IDentifier (UUID) URN Namespace"?

http://www.ietf.org/rfc/rfc4122.txt

cheers
Mark

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mark Mc Keown                            RSS
Mark.McKeown at man.ac.uk 	                 Manchester Computing
+44 161 275 0601     		         University of Manchester
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On Mon, 14 Nov 2005, Andreas Savva wrote:

> Minutes attached. Main topics:
> 	* EMS and CDDLM, ACS joint discussion
> 	* Naming Policy discussion
>
> https://forge.gridforum.org/projects/ogsa-wg/document/minutes-20051109
> /en/1
> --
> Andreas Savva
> Fujitsu Laboratories Ltd
>