Wed, Sep 14 2005 3:19 AM
Rob van der Meijden
PDC 2005 SO day
Not it’s not a typo, Ron Jacobs just prefers the term SO instead of SOA because all the hyping around it. Again an introduction to SO, boring ? No, not the way Ron is explaining it. He gave a very clear explanation in the four tenets of SO using a country with border as metaphor. After that 2 anti-patterns in SOA, namely
1. CRUDy interface; crud operations on the webservice interface just as you did when designing components with stateful conversation and operations which require multiple messages to complete the operation.
2. Loosey-Goosy; Trying to build a flexible and extensible service (for instance a method to query the database at the interface, DON’T)
And naturally 2 patterns:
1. Document interface; How to define a simple well to use interface ? Simple; create a response and request document (message) for each method.
2. Reservation; Maintain data consistency across long running processes. Prefer not to use the composition patters because you can’t rely that a service will composite a transaction. Use reservation by sending confirmation after de operation toke place. Take care off all possible outcomes (confirmed, cancelled or timed-out)
After the intro Arvindra Sehmi and Beat Schwegler gave a presentation on Modeling & Messaging for Connected Systems based on real life cases. They added a service model (next to the business and technology model) in their modeling strategy. They showed how to use this model with the use of UML techniques; Looks very use-full.
VSTS integration of wizards which create a solution and files that you need for the best practices of a SO implementation, wizard is known as WS-BAT. Couldn’t find anything on the internet except for this link.
Last subject fot today “the composite UI application block” typically useful for composite smart clients. These are clients which have discrete independent yet cooperative functional pieces. Looking good for this type of application.
Filed under: PDC