March 2005 - ogsa-wg - lists.ogf.org

RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Ian Foster 03 Mar '05

03 Mar '05

Savas: I wondered when you'd join the debate, and as usual your comments are very much to the point. At 06:09 PM 3/1/2005 +0000, Savas Parastatidis wrote: >Please note that I am not suggesting that WS-RF (and WS-Transfer for >that matter) is not useful in certain cases. Indeed, in the systems >management area it may make sense to use them. However, what it is being >proposed in the OGSA working group (if I understand correctly) is that >WS-RF be used as the foundation for all high-level services. I don't think that the OGSA working group would argue for using it as a foundation for "all high-level services," but I understand that some people fear that this is intended. For system management applications (a major focus of OGSA), I do believe that there is value, as you also note. >However, a difference >that I personally see between the WS-RF/WS-Notification and WS-Transfer/ >/WS-Eventing/etc. camps is that the latter is much simpler and "much simpler" is a relative term of course, but I think we should also remember that there isn't a lot to even the "more complex" WSRF/WS-BaseNotification. See Blackberry note below. >lightweight. Most importantly, the MS suite of specifications is not >promoted as the uniform, underlying suite of common messaging behaviours >for all high-level services as WS-RF seems to be. Instead it is some That's not my understanding of WSRF. >patterns that are available to be used where they are appropriate. Also, >WS-Transfer is lightweight so it can be used in very-small-factor >devices. I've seen WSRF implemented on a Blackberry, with the complete SOAP-WSRF-WSN-WSDM stack occupying 102KB. I *think* that the "small factor" issue is a red herring. If you want to run on something with just 64KB memory, you probably shouldn't be using Web services. >So, it would be interesting to understand from the WSRF architects where >they feel the WSRF approach is and is not appropriate. E.g. is it >appropriate for interactions with multiple resources? Should it be used >in the design of all high-level Grid services? What are the semantics of >the 'destroy' messages? Here's my opinions: * WSRF (or indeed any WS-I-compliant specification) should be used when and where it's appropriate. * Semantics of destroy: these are defined fairly clearly in the WS-ResourceLifetime specification. * Interactions with multiple resources: I think that's a red herring. E.g., a job factory can return EPRs to WS-Resources representing jobs, thus allowing individual jobs to be monitored and controlled, if needed. The factory can also maintain a service group representing all jobs, and then support operations that allow a client to "destroy all jobs that match a certain pattern" (for example). It's not an either/or. _______________________________________________________________ Ian Foster www.mcs.anl.gov/~foster Math & Computer Science Div. Dept of Computer Science Argonne National Laboratory The University of Chicago Argonne, IL 60439, U.S.A. Chicago, IL 60637, U.S.A. Tel: 630 252 4619 Fax: 630 252 1997 Globus Alliance, www.globus.org

1 0

Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Hiro Kishimoto 03 Mar '05

03 Mar '05

Kerl's email bounced. I agree with Karl. Actually we have had almost the same discussion at today's OGSA-WG call. We should sort out either (1) message level standards or (2) APIs for the higher level middleware. ---- Hiro Kishimoto Date: Thu, 3 Mar 2005 16:10:31 +0700 From: Karl Czajkowski <karlcz(a)univa.com> To: Steven Newhouse <sjn5(a)doc.ic.ac.uk> Subject: Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards' Sorry, but I think this is an example of the confused discussion we are seeing. You are clearly talking about programming environments with terms like "application code interface" and MPI as a rhetorical example. The question "to WSRF or not to WSRF", on the other hand, is really not a programming question at all. (To Globus Toolkit, or to WSRF.NET might be a more reasonable programming question.) MPI is largely a programming methodology, despite its name... it is an API (and build environment) standard that let you port application code from one host to another. MPI did not in any way give interoperability between platforms so that your application could run some tasks here, some tasks there, etc. across multiple vendor platforms. Specific implementations of MPI have tried to address platform heterogeneity over time, but unless I have missed some recent advance, there is still no runtime interop of MPI implementations. Most of the Web services standards are targeted at a completely different area of runtime system interoperation. The WSRF model and Microsoft's comparable proposals talk about basic ways to structure message interchange and more importantly on some protocol-level reflection mechnanisms to help "find" interop at runtime in a heterogeneous environment. The only programming methodology they imply is an accident of current vendor tools and prototypes! I find it an interesting question whether OGSA is trying to standardize a message-passing architecture or whether they are trying to standardize a programming environment. I think it is rather ambitious, and counter to current Internet-inspired strategies, to try to do both at once. If OGSA want to define programming environments, I think it is very appropriate that they define another "abstraction layer", namely a programming language binding to build or access distributed Grid systems. Hopefully you intend to model a message-passing system, or all bets are off as to how well this binding can map to Web service technologies in a globally distributed setting. If OGSA do not want to define programming environments but do have a message-passing architecture that they would like to specify "concretely" using Web service methods, I think they should continue this discussion of how WSRF and the MS proposals relate. But in doing so, they should not get distracted by red herrings about what an API looks like, how portable their code might be, etc. If OGSA is split on this point, I suggest that the people should split their discussions and proceed in parallel. It does seem that there is this recurring dead-end debate where one person is arguing about message protocol mechanisms with someone else who is arguing about application programs and their terminology accidentally collides. karl On Mar 02, Steven Newhouse loaded a tape reading: > >The idea of inventing "yet an other abstraction layer" doesn't sound > >very productive. > > Neither does the idea of re-writing my application code interface when > WS-RF 2.0 comes out, or something else gets adopted by another > community, or... > > Just imagine where the parallel computing world would still be if we > where still exposed to machine specific networking stacks instead of > MPI? Layers of abstraction are (within reason) good. > > Also you are seeing caution in the UK. Remember OGSI...? The UK put in > considerable effort to adopt the 'betamax' of grid web service. Are we > now being offered VHS grid web services? Or will there be another > Betamax type revision? > > I'm finding some of the comments in this thread (not Frank's) are bit > worrying. Should dissenters really be given a 'good talking to' until > they come round to the WS-RF point of view? Wow... roll on GGF! > > Steven > -- > ---------------------------------------------------------------- > Dr Steven Newhouse Tel:+44 (0)2380 598789 > Deputy Director, Open Middleware Infrastructure Institute (OMII) > Suite 6005, Faraday Building (B21), Highfield Campus, > Southampton University, Highfield, Southampton, SO17 1BJ, UK -- Karl Czajkowski karlcz(a)univa.com

1 0

RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Djaoui, A (Abdeslem) 03 Mar '05

03 Mar '05

I agree that defining the perfect layer of abstraction would be a good thing to do. But we have tried before and never got very far in agreeing on what that layer should be in a reasonable time. In order to make quick progress as expected from us, we would be better off discussing what it takes to compose WSRF services with non-WSRF (may be WS-Transfer?) services. some layers of integration (intermediaries, handlers,...) might be needed, but this is a small price to pay, compared to the alternatives of starting again or having a divided community. OGSA being a service oriented architecture will provide a choice of services. Market forces will ensure that the better services survive and the bad ones will be unused for a long time before they die peacefully. This way people can go their preferred way BUT AT THEIR OWN RISK but both approaches will be part of OGSA. Abdeslem. ///////// -----Original Message----- From: owner-ogsa-wg(a)ggf.org [mailto:owner-ogsa-wg@ggf.org]On Behalf Of Hiro Kishimoto Sent: 03 March 2005 08:19 To: 'OGSA-WG' Subject: Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards' Steven's email bounced. Steven, OGSA-WG is open to any plumbing proposal as our infrastructure service. However, we are under pressure from Grid community at large to publish concrete OGSA basic profile by GGF14. (And please use your registered email address.) Thanks, ---- Hiro Kishimoto Date: Wed, 02 Mar 2005 23:24:14 +0000 From: Steven Newhouse <s.newhouse(a)omii.ac.uk> To: Frank Siebenlist <franks(a)mcs.anl.gov> Subject: Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards' > The idea of inventing "yet an other abstraction layer" doesn't sound > very productive. Neither does the idea of re-writing my application code interface when WS-RF 2.0 comes out, or something else gets adopted by another community, or... Just imagine where the parallel computing world would still be if we where still exposed to machine specific networking stacks instead of MPI? Layers of abstraction are (within reason) good. Also you are seeing caution in the UK. Remember OGSI...? The UK put in considerable effort to adopt the 'betamax' of grid web service. Are we now being offered VHS grid web services? Or will there be another Betamax type revision? I'm finding some of the comments in this thread (not Frank's) are bit worrying. Should dissenters really be given a 'good talking to' until they come round to the WS-RF point of view? Wow... roll on GGF! Steven -- ---------------------------------------------------------------- Dr Steven Newhouse Tel:+44 (0)2380 598789 Deputy Director, Open Middleware Infrastructure Institute (OMII) Suite 6005, Faraday Building (B21), Highfield Campus, Southampton University, Highfield, Southampton, SO17 1BJ, UK

1 0

Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Hiro Kishimoto 03 Mar '05

03 Mar '05

Steven's email bounced. Steven, OGSA-WG is open to any plumbing proposal as our infrastructure service. However, we are under pressure from Grid community at large to publish concrete OGSA basic profile by GGF14. (And please use your registered email address.) Thanks, ---- Hiro Kishimoto Date: Wed, 02 Mar 2005 23:24:14 +0000 From: Steven Newhouse <s.newhouse(a)omii.ac.uk> To: Frank Siebenlist <franks(a)mcs.anl.gov> Subject: Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards' > The idea of inventing "yet an other abstraction layer" doesn't sound > very productive. Neither does the idea of re-writing my application code interface when WS-RF 2.0 comes out, or something else gets adopted by another community, or... Just imagine where the parallel computing world would still be if we where still exposed to machine specific networking stacks instead of MPI? Layers of abstraction are (within reason) good. Also you are seeing caution in the UK. Remember OGSI...? The UK put in considerable effort to adopt the 'betamax' of grid web service. Are we now being offered VHS grid web services? Or will there be another Betamax type revision? I'm finding some of the comments in this thread (not Frank's) are bit worrying. Should dissenters really be given a 'good talking to' until they come round to the WS-RF point of view? Wow... roll on GGF! Steven -- ---------------------------------------------------------------- Dr Steven Newhouse Tel:+44 (0)2380 598789 Deputy Director, Open Middleware Infrastructure Institute (OMII) Suite 6005, Faraday Building (B21), Highfield Campus, Southampton University, Highfield, Southampton, SO17 1BJ, UK

1 0

[ogsa-wg | Basic Profile - 1314] Relationship to WS-I Basic Security Profile 1.0
by Sourceforge Tracker Monitor 03 Mar '05

03 Mar '05

A new artifact has been added: 1314 Submitted by: Tom Maguire Submitted date: 2005-03-02 20:39:31 Respond by visiting: https://forge.gridforum.org/tracker/?func=detail&atid=780&aid=1314&group_id… (https://forge.gridforum.org/tracker/?func=detail&atid=780&aid=1314&group_id…) Summary: Relationship to WS-I Basic Security Profile 1.0 Project: Open Grid Services Architecture Tracker: Basic Profile Artifact ID: 1314 Category: <None> Group: <None> Status: Open Priority: - Last Modified By: Last Modified: 2005-03-02 20:39:31 Submitted By: Tom Maguire Submit Date: 2005-03-02 20:39:31 Assigned To: &lt;None&gt; File(s): <None> Description: Describe the extension model for BSP 1.0 View the Basic Profile : https://forge.gridforum.org/tracker/index.php?func=browse&group_id=42&atid=… (https://forge.gridforum.org/tracker/index.php?func=browse&group_id=42&atid=…)

1 0

Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Samuel Meder 02 Mar '05

02 Mar '05

On Mon, 2005-02-28 at 14:38 -0800, Frank Siebenlist wrote: > Could anyone summarize MS' WS-view, and how it differs from WSRF? So far I have not seen any substantial difference between the two approaches and I definitely believe the onus is on MS to show why people should adopt their proprietary specifications vs. adopting something that is being developed in a open standards body, is getting very close to a 1.0 version and has multiple implementations behind it. /Sam > > Thanks, Frank. > > > > Hiro Kishimoto wrote: > > >Hi all, > > > >Absorbing article by Tony Hey. > > > >http://news.tgc.com/nview.jsp?appid=360&print=1#342708 > >---- > >Hiro Kishimoto > > > > > > > >> GRIDtoday > >> NEWS AND INFORMATION FOR THE GLOBAL GRID COMMUNITY > >> --- February 28, 2005: Vol. 4, No. 8 --- > >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >>SPECIAL FEATURES > >>============================================================== > >> > >>[ ] M342708 ) WSRF? WS-*? Where is GGF's OGSA Headed? > >> By Tony Hey, Contributing Editor > >> > >> Tony Hey, director of e-Science for the Engineering and Physical > >>Science Research Council, continues to elaborate the need for open > >>standards in the realm of Web services-based Grid computing. He > >>discusses the great debate of WSRF vs. WS-*, and lays out what the GGF > >>must do with OGSA in order to give e-Science application developers > >>something to rally around. > >> > >> > > > > > > > -- Sam Meder <meder(a)mcs.anl.gov> The Globus Alliance - University of Chicago 630-252-1752

7 8

RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Djaoui, A (Abdeslem) 02 Mar '05

02 Mar '05

Just clarifying a rather small part of the big puzzle! >The argument is about whether support for WS-Addressing is all that is >required in order to interact with services built on top of WS-RF. I >believe this to be an oversimplification. Support for WS-Addressing is >absolutely required. However, it's not enough. It is enough, for a client to interact with a service that implements a WSRF specification. Note: I did not use the term build on top (this term might imply that WSRF implementations have to be provided by the infrastructure). The service simply implements one of the WS-* specifications (ie WSRF)! The client then uses messages exchanges as defined in that services description. >The implementation of the >semantics of the ResourceProperties and Lifetime related messages have >to be provided. If they are not provided, a developer will end up >implementing them. Absolutely, this is true of any web service specification, including WS-Transfer (no offence intended to any WS-* specification!) Abdeslem /////////

1 0

Proposed agenda for March 2nd call
by Hiro Kishimoto 02 Mar '05

02 Mar '05

Hi all, The following is a proposed agenda for OGSA-WG telecon on March 2nd Wednesday from 5pm to 7pm (CST). Dial-in numbers for Wednesday: Free: +1-888-452-0308 Intl/Toll: +1-484-644-0505 PIN: 71815 Screen share service will be provided. URL: http://ogsa.glance.net Session key: 0302 See more explanation: http://www-unix.gridforum.org/mail_archive/ogsa-wg/2004/06/msg00077.html 0) Celebration of OGSA v1 documents formal launce GFD.30, "The Open Grid Services Architecture, Version 1.0" GFD.44, "Open Grid Services Architecture Glossary of Terms" GFD.45, "Resource Management in OGSA" 1) Early discussion (10 min) Note taker assignment Roll call Telecon minutes approval (if available) GGF13 update (if any) Agenda bashing 2) Basic profile discussion (60 min) Revised basic profile draft https://forge.gridforum.org/projects/ogsa-wg/document/draft-ggf-ogsa-basic-… le/en/3 New configuration of Issue tracker https://forge.gridforum.org/tracker/index.php?func=browse&group_id=42&atid=… 3) Profile template discussion (if available) 4) Roadmap discussion (if available) 5) Wrap up (10 min) AOB Mar. 7 (5-7pm CST) BES BoF preparation Basic profile discussion, basic security profile Mar. 9 (10-11am CST) Data Design team Mar. 9 (5-7pm CST) Roadmap discussion, GGF13 session preparation Mar. 13-16 GGF13 in Soeul See telecon schedule until GGF: https://forge.gridforum.org/projects/ogsa-wg/document/telecon_schedule ---- Hiro Kishimoto

1 0

RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Timesfor GGF & Standards'
by Hiro Kishimoto 02 Mar '05

02 Mar '05

Marty's email bounced. ---- Hiro Kishimoto From: "Marty Humphrey" <humphrey(a)cs.virginia.edu> To: "'Mark Morgan'" <mmm2a(a)virginia.edu>, <daveb(a)nesc.ac.uk>, <gannon(a)cs.indiana.edu>, <foster(a)mcs.anl.gov> Cc: <meder(a)mcs.anl.gov>, <ogsa-wg(a)gridforum.org>, <tony.hey(a)epsrc.ac.uk>, "'Marty Humphrey'" <humphrey(a)cs.virginia.edu> Subject: RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Timesfor GGF & Standards' Date: Tue, 1 Mar 2005 13:26:55 -0500 Folks, At the risk of jumping into this late... We have a full-featured implementation of WSRF available right now via http://www.ws-rf.net Regarding "MS's position" on WSRF.... First, there is largely NOT a "single MS", as "Microsoft Research Cambridge" is not "Microsoft Research Redmond", and neither of them are "MS Corporate". My team's project interacts most closely with Microsoft Research Redmond, which neither "endorses" our work or "dismisses" our work because it may or may not conflict with "MS Corporate" business models and/or corporate specifications. I note however that we have a decent number of conversations with both Microsoft Research Redmond and Microsoft Corporate regarding our research project. Our dialogues focus on the utility of WSRF, the alternatives to WSRF, the use of the MS tooling, etc. Microsoft Research and Microsoft Corporate have always been very interested in our project -- what we're doing, and why. We have great feedback and conversations. I have nothing but good things to say about MS Corporate/Research. Our project's focus has always been, I believe, a proper mix of research and development. It's not necessarily our mission to ONLY build something that completely aligns with the Microsoft corporate mission and tooling -- neither is our mission to create something just for the sake of creating it! If the MS tooling and approach solves "The Problem"(tm), then we'll be happy to just use it. To date, I'm not sure that this is the case (hence our project's existence). In summary, I think we have a solid implementation of WSRF.NET and we're very committed to supporting it and broadening it. Please let me know if there are specific questions that I can answer! (As I mentioned, I jumped in a little late, so I'm not sure if I am really commenting on the "right" issues). -- Marty Marty Humphrey Assistant Professor Department of Computer Science University of Virginia > -----Original Message----- > From: owner-ogsa-wg(a)ggf.org [mailto:owner-ogsa-wg@ggf.org] On Behalf > Of Mark Morgan > Sent: Tuesday, March 01, 2005 12:10 PM > To: daveb(a)nesc.ac.uk; gannon(a)cs.indiana.edu; foster(a)mcs.anl.gov > Cc: meder(a)mcs.anl.gov; ogsa-wg(a)gridforum.org; tony.hey(a)epsrc.ac.uk > Subject: RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging > Timesfor GGF & Standards' > > Isn't WSRF.NET at the University of Virginia essentially proof of > this? > > -- > Mark Morgan > Research Scientist > Department of Computer Science > University of Virginia > http://www.cs.virginia.edu > mmm2a(a)virginia.edu > (434) 982-2790 > > > -----Original Message----- > > From: owner-ogsa-wg(a)ggf.org [mailto:owner-ogsa-wg@ggf.org] On Behalf > > Of Dave Berry > > Sent: Tuesday, March 01, 2005 12:07 PM > > To: Dennis Gannon; Ian Foster > > Cc: Samuel Meder; ogsa-wg; Tony Hey > > Subject: RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging > > Times for GGF & Standards' > > > > Hi Dennis, > > > > MS were definitely in evidence at the meeting that Tony reported in > > his GridToday article. Whether the MS people there represented > > official company policy is less clear, but certainly those people > > have had some influence in the UK e-Science community. > > > > Other people are concerned that if MS do not explicitly support > > WSRF, this will make it harder to develop and/or deploy Grid > > services on MS systems. WSRF supporters say that this will have no > > effect, as the support that MS has for WS-Addressing is sufficient. > > It seems to me that this question could be settled by experiment. A > > WSRF supporter who is fluent in .Net could sit down with some of the > > sceptics while they attempt to create a WSRF service. > > > > Dave. > > > > > -----Original Message----- > > > From: owner-ogsa-wg(a)ggf.org [mailto:owner-ogsa-wg@ggf.org] > > On Behalf > > > Of Dennis Gannon > > > Sent: 01 March 2005 12:54 > > > To: Ian Foster > > > Cc: Samuel Meder; ogsa-wg; Tony Hey > > > Subject: Re: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: > > > 'Challenging Times for GGF & Standards' > > > > > > hi Ian, > > > i agree that this consistency is critical. But how much WSRF or > > > ws-trans/ws-enum must be visible to the application > > builder? Perhaps > > > it is essential that one or the other must be exposed. i > > don't know. > > > perhaps doing so just adds another layer abstraction layer as > > > frank suggests. but it may also be that we have defined the wrong > > > abstraction layers to start from. again, i don't know. > > > > > > my other point is this: i don't see this as a debate with > > MS. i see a > > > debate right in the core of GGF membership. from what i > > can see, MS > > > is a no-show at this party. > > > > > > dennis > > > > > > On Mon, 28 Feb 2005, Ian Foster wrote: > > > > > > > Dennis: > > > > > > > > I'm not sure that the "we don't need WSRF" is the heart of > > > the debate. If > > > > it was, then I think things are fairly clear: WSRF is just > > > some conventions > > > > for the messages that you send to do certain things (e.g., > > > > getResourceProperty to get state, Terminate to destroy > > something, or > > > > whatever the names are) in a WS context. If you don't have those > > > > conventions, then everyone ends up defining their own, so > > > that e.g. a job > > > > management interface might have "getJobStatus" and > > > "destroyJob", a file > > > > transfer interface might have "getTransferStatus" and > > > "destroyTransfer". > > > > This lack of consistency just makes life difficult, without > > > providing any > > > > benefits. > > > > > > > > The debate with MS, as I understand it, seems to rather > > > relate to the fact > > > > that they are promoting a *different* set of conventions > > > for doing similar > > > > things, e.g., WS-Transfer instead of WS-ResourceProperties. > > > > > > > > Ian. > > > > > > > > > > > > > > > > At 10:23 PM 2/28/2005 -0500, Dennis Gannon wrote: > > > > >hi Sam, > > > > >i don't think MS has any orchestrated view on WSRF at all > > > (but i may > > > > >be wrong.) I think it is more the case that there are > > > people working on > > > > >grid standards (outside of microsoft) that feel that what > > > exists in the > > > > >ws-spec world is sufficient. hence if there is any onus, > > > it is on those > > > > >folks to show us that this is true. what tony is saying > > > is that users, > > > > >i.e. application builders, should not have to deal with > > > these details. The > > > > >should see clearly defined OGSA services and they should > > > have an easy > > > > >to understand set of interaction patterns to use these > > > services to build > > > > >thier applications. the OGSA point of view is that to be > > > precise in > > > > >the definition of these behavior patterns requires a > > > framework like wsrf. > > > > > > > > > >i actually feel that these things can all coexist. but > > > from the politics > > > > >of "what is simple", we seem to live in interesting times. > > > > > > > > > >dennis > > > > > > > > > >On Mon, 28 Feb 2005, Samuel Meder wrote: > > > > > > > > > > > On Mon, 2005-02-28 at 14:38 -0800, Frank Siebenlist wrote: > > > > > > > Could anyone summarize MS' WS-view, and how it > > > differs from WSRF? > > > > > > > > > > > > So far I have not seen any substantial difference > > > between the two > > > > > > approaches and I definitely believe the onus is on MS > > > to show why people > > > > > > should adopt their proprietary specifications vs. > > > adopting something > > > > > > that is being developed in a open standards body, is > > > getting very close > > > > > > to a 1.0 version and has multiple implementations behind it. > > > > > > > > > > > > /Sam > > > > > > > > > > > > > > > > > > > > Thanks, Frank. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hiro Kishimoto wrote: > > > > > > > > > > > > > > >Hi all, > > > > > > > > > > > > > > > >Absorbing article by Tony Hey. > > > > > > > > > > > > > > > >http://news.tgc.com/nview.jsp?appid=360&print=1#342708 > > > > > > > >---- > > > > > > > >Hiro Kishimoto > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >> GRIDtoday > > > > > > > >> NEWS AND INFORMATION FOR THE GLOBAL > > > GRID COMMUNITY > > > > > > > >> --- February 28, 2005: Vol. > > 4, No. 8 --- > > > > > > > >> > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > > > > >>SPECIAL FEATURES > > > > > > > > > > >>============================================================== > > > > > > > >> > > > > > > > >>[ ] M342708 ) WSRF? WS-*? Where is GGF's OGSA Headed? > > > > > > > >> By Tony Hey, Contributing Editor > > > > > > > >> > > > > > > > >> Tony Hey, director of e-Science for the > > > Engineering and Physical > > > > > > > >>Science Research Council, continues to elaborate > > > the need for open > > > > > > > >>standards in the realm of Web services-based Grid > > > computing. He > > > > > > > >>discusses the great debate of WSRF vs. WS-*, and > > > lays out what the > > > > > > GGF > > > > > > > >>must do with OGSA in order to give e-Science > > > application developers > > > > > > > >>something to rally around. > > > > > > > >> > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > Sam Meder <meder(a)mcs.anl.gov> > > > > > > The Globus Alliance - University of Chicago 630-252-1752 > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________________________ > > > > Ian Foster www.mcs.anl.gov/~foster > > > > Math & Computer Science Div. Dept of Computer Science > > > > Argonne National Laboratory The University of Chicago > > > > Argonne, IL 60439, U.S.A. Chicago, IL 60637, U.S.A. > > > > Tel: 630 252 4619 Fax: 630 252 1997 > > > > Globus Alliance, www.globus.org > > > > > > > > > > > > > >

1 0

RE: [ogsa-wg] RE: GRIDtoday Edition: Tony Hey: 'Challenging Times for GGF & Standards'
by Savas Parastatidis 02 Mar '05

02 Mar '05

Dear Ian, > I'm not sure that the "we don't need WSRF" is the heart of the debate. If > it was, then I think things are fairly clear: WSRF is just some > conventions for the messages that you send to do certain things (e.g., > getResourceProperty to get state, Terminate to destroy something, or > whatever the names are) in a WS context. I think that there are still issues being debated as to when it is appropriate to use WSRF (or something like it) in the design of services for inter-enterprise/Internet-scale/Grid computing. For example, two issues that are I think worth discussion are efficiency and whether or not WSRF is needd to capture common application semantics. To take them in turn... a) efficiency. > If you don't have those > conventions, then everyone ends up defining their own, so that e.g. a job > management interface might have "getJobStatus" and "destroyJob", a file > transfer interface might have "getTransferStatus" and "destroyTransfer". The WSRF way of doing things promotes a view where all 'stateful resources' are addressable and able to receive messages (i.e. they are logical recipients of messages). As a result, service designers are encouraged to think in terms of messages that are targeted towards single resources. However, sending and receiving messages has a high cost when sending them across the Internet and there are many cases where it would be more efficient to define message interactions which involve multiple resources. For example sending the following message to a service: 'getJobStatus' of job1 and job2 and job3 and job4 and... jobN Is more efficient than sending individual messages to n individual resources of the form: 'getResourceProperties' jobK (the same would be true of 'destroyJob' vs WSRF 'destroy' messages). The former approach is a general case since it allows us to get the status of one or multiple jobs in one message. Also, it is application specific since the semantics of the interaction tells us what to expect. The latter approach is specific to only one resource at a time. Multiple message exchanges are necessary to achieve the same thing as the 'getJobStatus' approach or yet another abstraction (e.g. service groups, which introduces extra complexity and message exchanges) has to be introduced. Effectively the resource-oriented view of WSRF leads designers to inefficient use of the network and the services involved in interactions. Also, current Web Services tooling will allow me to easily define the getJobStatus message in WSDL and it will automatically generate the code for me. I do not see the great advantage of having a generic getResourceProperties message when it comes to designing high-level services: it is the structure and contents of the document returned that it is important, rather than how it is accessed. A generic getResourceProperties could be of use when we require common application semantics (in the same way REST is designed) and we need document transfer. However, in such a case the more lightweight solution of WS-Transfer with its CRUD semantics could be used. 2) Does WSRF capture common application semantics? > If you don't have those > conventions, then everyone ends up defining their own, so that e.g. a job > management interface might have "getJobStatus" and "destroyJob", a file > transfer interface might have "getTransferStatus" and "destroyTransfer". > This lack of consistency just makes life difficult, without providing any > benefits. > It is not clear to me how to model "kill", "cancel", "pause", "suspend" for a job using WSRF... all these messages carry different semantics that cannot be captured by a single "destroy" message. Also, is there a suggestion that the semantics of "destroy" are common across all application domains? For example, what does it mean to "destroy" a database resource? What can the sender of the message assume about the effect of the generic "destroy" message? Does it mean that the database is droped or just disconnected? If we need to create specific interactions to capture the different semantics in the case of kill/cancel/pause/suspend and drop/disconnect, what is the value of a generic 'destroy' message for all high-level services? Please note that I am not suggesting that WS-RF (and WS-Transfer for that matter) is not useful in certain cases. Indeed, in the systems management area it may make sense to use them. However, what it is being proposed in the OGSA working group (if I understand correctly) is that WS-RF be used as the foundation for all high-level services. > The debate with MS, as I understand it, seems to rather relate to the fact > that they are promoting a *different* set of conventions for doing similar > things, e.g., WS-Transfer instead of WS-ResourceProperties. > I won't pretend to know of Microsoft's intentions. However, a difference that I personally see between the WS-RF/WS-Notification and WS-Transfer/ /WS-Eventing/etc. camps is that the latter is much simpler and lightweight. Most importantly, the MS suite of specifications is not promoted as the uniform, underlying suite of common messaging behaviours for all high-level services as WS-RF seems to be. Instead it is some patterns that are available to be used where they are appropriate. Also, WS-Transfer is lightweight so it can be used in very-small-factor devices. So, it would be interesting to understand from the WSRF architects where they feel the WSRF approach is and is not appropriate. E.g. is it appropriate for interactions with multiple resources? Should it be used in the design of all high-level Grid services? What are the semantics of the 'destroy' messages? Best regards, -- Savas Parastatidis http://savas.parastatidis.name

3 2