- From: Chris Harding <c.harding@opengroup.org>
- Date: Tue, 10 Jul 2007 11:43:14 +0100
- To: "Danny Ayers" <danny.ayers@gmail.com>, "Elisa F. Kendall" <ekendall@sandsoft.com>
- Cc: "AJ Chen" <canovaj@gmail.com>, mpbelanger@jarg.com, semantic-web@w3.org, soa-ontology@opengroup.org
Hi - I would just like to reinforce Danny's point about the potential importance of the Semantic Web for Model-Driven Architecture. In The Open Group, we are working on an ontology for SOA, partly because we believe that such an ontology can be a basis for a model-driven approach to implementation. We have selected OWL as the language for this ontology precisely because of its power in enabling ontologies created by different bodies to be linked via the Web. There has been work done on ontologies for Web Services that demonstrates that the combination of an ontology for the architecture method with a domain ontology for the application can enable automated generation of service interface definitions. With OWL, the domain ontology can be anywhere on the Web - or could even consist of a number of linked ontologies created by different organizations. This means that definitions can easily be created for services for use by collaborating organizations, and it will also make re-use of those services much easier. We believe that SOA is a sufficiently well-structured approach that this ability to generate service definitions can be extended from Web Services to SOA. (We are perhaps less optimistic, however, about the automatic generation of implementation code - this looks to be a much harder problem.) An early draft of this ontology was exposed for comment within the OMG, the SOACoP, and W3C late last year and early this year. We hope to expose a later draft for comment this summer (it has developed significantly), and then proceed to publication. I wish I could get to the meeting in Palo Alto, but geographical considerations will unfortunately prevent this (I am based in the UK). I would be very interested to learn the results of the discussions there. At 09:01 10/07/2007, Danny Ayers wrote: >On 10/07/07, Elisa F. Kendall <ekendall@sandsoft.com> wrote: >> >> Hi Michael, >> >> Actually, the work we've been spearheading within OMG is not only moving >>towards ontology-based SOA, but is actually much broader than that. The >>Ontology Definition Metamodel (ODM), available at >>http://www.omg.org/cgi-bin/doc?ptc/2006-10-11, provides a >>starting point for much more general "Semantic Web Enabled Software >>Engineering", a phrase coined by Evan Wallace (NIST) a few years ago when we >>first started pulling some of these ideas together for workshops at ISWC. > >Personally I very much welcome the OMG work (and the SDForum event >sounds mighty interesting), but I would just like to chip in on a >point that seems very important. > >While joining together the worlds of MDA, ontology-based modelling and >SOA has the potential to be a big step forward on the road to the >Semantic Web, I really hope one particular aspect will be given >appropriate consideration. This is the "Web" in Web Ontology Language, >the "Resource" in Resource Description Framework. > >Without strong recognition of the Web's protocol HTTP with its core >concepts of resources (/URIs) and methods all we have is yet another >set of logical models for knowledge representation. I have no doubt >about the intrinsic benefits of ontology languages for working with >heterogenous real-world information (compared to say straight OO, >Codd's relational model or even Prolog...), but without fully >acknowledging the Web side, potentially the biggest benefit may be >overlooked - the Semantic Web itself. > >Coming from the direction of general Web development the notion of a >Resource-Oriented Architecture (ROA) has recently emerged. This is >derived from the base specs of the Web, Fielding's thesis, and like >the W3C Technical Architecture Group's WebArch document [1] has the >validation of practical experience in Web development to date. The >ideas are laid out in Richardson & Ruby's book RESTful Web Services >[2] and Google knows of many related blog posts. While this book is >lacking material on specifically Semantic Web technologies (which is >flabbergasting, see [3]), the ROA approach is entirely consistent with >Semantic Web Enabled Software Engineering. > >For the Web developer at large, ROA offers an approach to services >that while broadly aligned with the general principles of SOA largely >bypasses the arcane, convoluted and often not Web-friendly >technologies (RPC!) found in the SOAPy Web Services stack. > >It seems to me that without recognition there is a relatively simple >Web-oriented approach to system development (with resources and a >uniform interface based on URIs and the verbs of HTTP featuring >prominently), any ontology-based MDA strategy runs the risk of >overengineering and becoming a Byzantine stack comparable to that of >WS-*, largely disjoint from developments on the Web. This could easily >be counter-productive to future software development in the new >globally-networked environment. > >In short, I'd suggest the Semantic Web is most productively viewed as >an extension of the current Web rather than as traditional >(comparatively monolithic) software with shallow Web characteristics >added as an afterthought. This is irrespective of the sophistication >of the object modelling techniques taken in isolation. I do hope the >good people of the OMG bear this in mind. > >Cheers, >Danny. > >[1] http://www.w3.org/TR/webarch/ >[2] http://www.crummy.com/writing/RESTful-Web-Services/ >[3] http://blogs.sun.com/bblfish/entry/restful_web_services_the_book > >-- > >http://dannyayers.com Regards, Chris +++++ ======================================================================== Dr. Christopher J. Harding Forum Director for SOA and Semantic Interoperability THE OPEN GROUP Thames Tower, 37-45 Station Road, Reading RG1 1LX, UK Mailto:c.harding@opengroup.org Phone (mobile): +44 774 063 1520 http://www.opengroup.org Enterprise Architecture Practitioners Conference Four Seasons, Austin, Texas, US, July 23 - 25, 2007 Member Meetings: July 23 - 27, 2007 http://www.opengroup.org/austin2007/ ======================================================================== TOGAF is a trademark of The Open Group
Received on Tuesday, 10 July 2007 10:51:45 UTC