techno.blog("Dion")

The Jini camp is trying to be heard again. This time, Sean Landis is talking about Service Oriented Architectures – Separating Hype From Reality.

Using Jini for SOA’s is an after thought, yet has been successful (e.g. Orbitz). Now there is a fight for the world of “grid computing” which Jini has been known for in the past.

Having a wife who has a masters in education, I am used to hearing about Pedagogical means too ;)

Here are Seans conclusions:

Web services has begun to slide down into the trough of disillusionment. For reference, Jini appears to have passed through the trough of disillusionment and is climbing up the slope of enlightenment. (These are my estimates. You can see exactly how the Gartner Group evaluates them for only $495). How deep will the web services trough be? Will it find a niche after enlightenment? I think so.

Web Services is a great integration technology (like a modern EDI). It provides a “common backplane” for weaving together disparate functions and allowing them to work together. For the IT department, web services is a Godsend. In that universe, the endpoints can be managed to ensure true interoperability. Whether web services is better at this than something else, say Jini, is a arguable. For example, if there’s a degree of dynamic behavior, if services may come and go, then Jini would be better. If the environment is static, then web services is great.

Web services is a good tool for exporting non-web services to a web environment. In the IT world, a web-based SOA has the advantage of utilizing a browser as the client. This can ease development, but there are still problems. For example, one must standardize on a set of browser primitives or require a baseline browser. Furthermore, the client is fairly limited in what it can do computationally. With Jini, the proxy and the UI are actually written by the service provider and dynamically downloaded to the client as needed. There is a base JVM requirement, but in practice, this tends to be easier to manage than the browser problem. Furthermore, the proxy can contain significant sophistication that goes beyond what a web service application can provide.

Web services are not good for complex systems including service ecologies (SOA). For very simple service interactions, web services may be sufficient, but they may not be justified due to the cost of implementation and deployment. The bottom line is that there are too many important characteristics lost due to the design assumptions of hiding remoteness and providing language-independence. If you are considering employing SOA, then consider what’s been written here, and consider a pure Java and Jini approach over Web Services for building your Service Oriented Architecture.