To the best of my knowledge, WS-Naming has in no way said anything about how uniqueness is to be achieved. They certainly haven't gone so far as to talk about which algorithm everyone should use though that may happen in the future. -Mark
-----Original Message----- From: owner-ogsa-wg@ggf.org [mailto:owner-ogsa-wg@ggf.org] On Behalf Of Maguire_Tom@emc.com Sent: Monday, November 14, 2005 9:55 AM To: zzalsmm3@nessie.mcc.ac.uk; andreas.savva@jp.fujitsu.com Cc: ogsa-wg@gridforum.org; ogsa-naming-wg@ggf.org Subject: RE: [ogsa-wg] Teleconference minutes - 9 November 2005
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@ggf.org [mailto:owner-ogsa-wg@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@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