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@univa.com> To: Steven Newhouse <sjn5@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@univa.com