On the first day of the JAOO conference (with over 1000 attendees this year!), after Werner's excellent keynote about the Amazon.com technology platform (which, BTW, is service-oriented), Gregor Hohpe hosted the SOA Track. He opened the track with a quick yet deep overview of SOA -- probably the most useful introduction to SOA I've ever heard.
Following Gregor's introduction, I gave my talk on dynamic languages and SOA. For better or worse, SOA is often associated with large and sometimes expensive "enterprise" software systems, where your choice of programming language tends to be limited to Java or C++. I encouraged the attendees to avoid being "enterprisey," which is defined as coming up with vastly overblown architectures or designs for the problem at hand. There are many functions within a SOA that can be handled by just a few lines of Ruby, Python, or JavaScript, rather than hundreds of lines of Java or C++. I also gave some examples of scripting JAX-WS with ECMAScript for XML (E4X) in CeltiXfire, scripting Artix with Ruby, and scripting clients for Qpid with Ruby and Python.
After lunch, Ivo Totev of Software AG talked about SOA governance. This is one of the newest aspects of SOA, and it's particularly important because it raises the issues above the pure technology level to how SOA systems are deployed, managed, and extended over time, understanding how changes to parts of a system are going to affect the overall system, and how SOA systems can be made to properly reflect the appropriate business operating procedures. Governance is often a term that's thrown about without much definition or depth behind it, but Ivo gave it a very thorough and informative treatment.
Next up was Beat Schwegler from Microsoft, who talked about how to architect applications for SOA. Beat hammered home the point that there's a huge difference between technology and business, that SOA ultimately is about reducing the cost of doing business, and that technology is subservient to that need. He pointed out that technology flexibility is a benefit of SOA that allows the business to control its cost of IT. Beat gave the example of moving services off of a mainframe to reduce costs without breaking users of those services: this is much more feasible with a service focus rather than a technology focus. He talked about the folly of trying to build reusable services right off the bat, explaining that you first have to have "use" before you can move on to "reuse." Beat then covered service contracts, architectural refactoring, and application partitioning, all required to create adequate boundaries within a SOA so as to ensure that it's properly abstracted and give it the required business flexibility.
Following the break, Gregor again took the stage, this time to talk about loosely coupled conversations. Coupling is extremely important in SOA systems because if subsystems are coupled too tightly, the business agility you seek by adopting SOA ends up eluding you. Conversations between subsystems obviously impact the degree of coupling present in the system. Gregor explained various message exchange patterns, choreography, and approaches for verifying message exchange rules. He then gave an overview of several service conversation description standards, including BPEL, CDL, and SSDL, each of which takes a different approach to defining and prescribing conversations. He explained that the outputs of tools based on these standards are meant for machine, not human, consumption, and so then moved on to explain a number of conversation patterns, which are far more human-friendly.
We capped off the SOA Track with a panel consisting of all the track speakers as well as Frank Buschmann of Siemens AG, whom Gregor invited as a devil's advocate of sorts. The panel stressed the fact that SOA isn't magic, and that doing it right required all the non-technical business factors to be addressed by the organization's leadership. Even Werner, who normally asks really hard questions at such panels, said that he thought the panelists were on the right track.
What was most impressive to me about the SOA Track is that none of the speakers communicated about their talks or exchanged slides before the conference, yet the messages of all the track's speakers meshed very well. Furthermore, despite the heavy technical leanings of the audience, they too understood that SOA is ultimately not about technology but about creating business value. I believe this is all good testament not only to the expertise of my fellow SOA Track speakers, but to JAOO's amazing ability to always attract highly knowledgeable speakers and attendees who possess formidable hands-on experience.
And finally, what JAOO would be complete without a great conference party! The Monday evening event was outstanding, as usual, complete with Chili John's excellent "Route 66" buffet, a great performance by the Absolute Girls, and some really nice locally-brewed beer.