Architect Consultant blog

One of the better features of the Oracle SOA Suite 11g is the Error Hospital in which errors are handled uniformly accross SCA components. But you have to think twice before you use error retry mechanisms for a Composite within a SOA! This because a Composite (or Service) can be used within Service Compositions. This is one of the Service Oriented principles (as can be read within the books of Thomas Erl). So a Service is not aware in which context it is (and may be) used. It can be part of a Business Service. So the Service can not decide how to handle errors and can certainly not have a manual recovery, because in some context this will be wrong. Just be aware that your SCA Composite can always be a Service Composite member !!

With the support of SCA within the Oracle SOA Suite 11g you get basically two busses: The Mediator (the "old" OESB) and (as a separate product) the OSB 11g. The Mediator is positioned as wiring intra Composite and the OSB to wire enterprise Services. A question that puzzles me is if it is wise to (always) expose all Services via the OSB? In that case the OSB is your abstraction Service entry layer and all Services are reachable and configurable through the bus. This way you use the loose coupling strategy of Proxy- and Business Services within the OSB. What is your experience or opinion on this?

I bought this book to get a global overview of the possibilities of SCA, because it is also implemented within the Oracle SOA Suite 11g. It is the first book on the fairly new SCA standard. If you want to get a global overview the first chapter will already do. The next chapters go deeper into the concepts with Java as the example programming language. Chapter 1 - Introducing SCA The book starts with a global introduction of SCA and its place w.r.t. SOA, J2EE, .NET, Spring and distributed computing. SCA focuses on being able to describe assemblies of components which have been written in a variety programming models and protocols . It does not cover presentation and persistency. Within this chapter the main terms are explained: Service , Component , Composite and Domain . Why another standard? Because there are still some issues with J2EE and .NET, namely complexity and reusability. You have to understand a lot of different technologies like JAX-WS, JMS, EJB, ASP.NET, .NET M...

To get an overview of the possibilities of the Software Component Architecture (SCA) standard you should read this blog . Also Oracle supports the SCA standard . This standard let you define new components by using other components no matter which technology and protocol used. The wiring is done through configuration. Curious if this will be used a lot by the community! Note: The Oracle SOA Suite 11g does not contain the AquaLogic Bus, this is a separate product from Oracle.