"SOA is Dead" Questions

Anne Thomas Manes from Burton Group recently posted an article related to the Death of SOA. Many customers that I work with who are in the middle of SOA Projects had questions on the article. Anne's presentation on SOA Fatigue at the SOA Symposium was also a prelude to this posting. If one examines the article, you can draw the following points:


- SOA Technologies from various vendors have become obtuse, costly and difficult to implement
- Enterprise SOA success in the marketplace is limited to a small collection of customers and is not widely seen due to the amount of effort to establish the entire Inventory.
- Service-orientation principles are still valid and important in providing value to the customer.
- Services should be the focus not SOA.

If one is attempting to apply SOA to a domain or Enterprise, we should revisit the goals of SOA:

- Intrinsic Interoperability
- Vendor Independence
- Increased Federation
- Business and Technology Domain Alignment
- Increased ROI
- Organization Agility
- Reduced IT Burden

These goals are then supported by the following principles of service-orientation

- Standardized Contract
- Loose Coupling
- Reusability
- Abstraction
- Autonomy
- Statelessness
- Discoverability
- Composability

The application of service-orientation helps guide business analysts and architects towards resuable, agnostic services. By following these principles, we in affect are directly supporting interoperability, vendor independence and federation. Service development also benefits from business and technology domain alignment when analyzing existing processes in an Inventory Analysis.

The success of customers I work with has been on supporting a domain versus the entire Enterprise. Success of the domain efforts in several cases has caused the business side of the organization to consolidate functionality in other divisions to leverage the domain services and their demonstrated benefits.

The key in Anne Thomas Manes blog is that the fundamental piece of SOA, the service, is still important. A service is logic that has applied service orientation to a meaningful extent. This in combination with SOA Design Patterns provides the architect/developer with a solid foundation for realizing the benefits. How you the develop, register, host, monitor the service can be done in a heterogeneous way with a wide range of standards, technologies and patterns.

SOA Design Patterns Online

In a previous post I talked about the first SOA Symposium held in Amsterdam last October. One of the book releases from Thomas Erl was SOA Design Patterns which is now available in an updated form online. Check out www.soapatterns.org. In addition to the published patterns are candidate patterns around REST, binary data transmission and others.

WOA versus SOA

My discussion point in my last entry discussed how SOA is agnostic in which technology should be used to employ it. Joe McKendrick and Dion Hinchcliffe at ZDNet along with research I did for a client identified a growing interest in using REST to support SOA. ZDNet refers to it as Web Oriented Architecture, a subset of SOA.

Dion Hinchcliffe's discussion on WOA

Some points that are referred to in these articles identify these characteristics:

- HTTP(S)
- POX
- JSON

Effectively from the runup of Web 2.0 technologies, the ever increasing amount of public APIs, and the increasing amount of mashups that are being performed, Web Resources are more available then Web Services. WOA is being identified as the necessary amount of complexity to get the job done.

If we compare WOA to SOA, there are some distinct differences with one distinct one being the Service or Resource Contract. WSDL/XSD/WS-Policy are front in center for describing a Web Service. Within REST, the contract is implicit and is based on HTTP verbs and XML Schema. If developing a web service, the contract analysis, design and development effort is the main focus whereby the service foundation layer and data representation layer are identified. In WOA, the data representation layer is the focus instead.

Web Services != SOA

During a recent trip to a company technical summit a discussion came about related to how SOA is just Web Services. As a SOA Trainer, Architect and Implementer I live and breath it every day. Most peoples perspectives probably fall in this category and currently most of the SOA implementations that I have worked with have used Web Services. The key is that Web Services is just an implementation technology not a SOA.

Books from Thomas Erl, Intel Press and others have identified that SOA is a design paradigm that focuses on a series of principles that tie back into key business goals and benefits. Examples of these are presented at SOA Systems but include:

- Interoperability
- Federation
- Cooperative Development between Business Analysts and Technical Architects
- Vendor/Technology Choice
- ROI
- Reduced IT Effort
- Business Agility

Now a SOA could be constructed using CORBA, Java, SCA/SDO, Web Services, REST etc. The implementation mechanism that one chooses should support interoperability, federation etc. Currently XML Based technologies provide the best interoperability both in communication/exchange but in vendor support, standards, tooling but this may change over time and probably will.

So if a person asks me what SOA is, I simple identify it as a design paradigm for developing and evolutionary distributed architecture. It has its basis in OO, AOP, EAI, BPM and other styles. It is like the Bruce Lee of architectures having evolved from various fighting styles.

SOA Design Patterns

As part of the SOA Symposium I was excited to watch the release of the latest Prentice Hall title, SOA Design Patterns by Thomas Erl. This is a large effort and I was fortunate to be asked by Thomas to participate in a contributing author capacity. Over 80+ patterns are outlined and include many of the speakers at the SOA Symposium. It is good to see such cooperation and the development of more independent material for the international audience. Some of the patterns are available at www.soapatterns.org which will be updated to match the book as well as candidate design patterns.

Another title that I am very interested in reviewing is also another Prentice Hall title, Web Service Contract Design & Versioning for SOA.

SOA Symposium 1.0

Well it has been quite awhile since I have posted but now that I have a few minutes I figure I would discuss my experience at SOA Symposium 1.0 in Netherlands, Amsterdam. I am working for SOA Systems delivering SOA training this week and was fortunate to speak at three sessions and participate in a panel discussion with my peers. I was very impressed with the quality of sessions and speakers that were able to take time out and share their thoughts on the future of SOA. Check out www.soasymposium.com and look for publicly available content sometime in the future.

There was a lot of discussion on how SOA Governance is becoming more important along with more efficient platforms and alternative consumers. One common thread in my discussion with attendees was how important the people quotient is in creating a successful SOA.

Cape Clear ESB (Workday) Assemblies Context Options

One client I am assisting is the Cape Clear ESB and it Assembly functionality. This provides mediation support via a Spring Bean configuration file which is generated via graphical drag/drop tools. Because the Assembly Service is stateless and the project we were working on required some context sharing, we had to open up the covers and learn about org.springframework.context.ApplicationContext and org.springframework.beans.factory.InitializingBean. A single bean with a scope of singleton was developed to provide context for all instances of the assembly and when the assembly was loaded this information was initialized as part of the afterPropertiesSet() method.

Within each instance of the assembly, Cape Clear provides another context called com.capeclear.mediation.MediationContext which provides a setProperty() and getProperty() method. This provides simple storage of variables within an instance.