More and more people are realizing that Web Services are not the only way to implement SOA based application. A recent InfoQ discussion thread, raised this discussion again:
Jason [Bloomberg] thinks it is now the time to better separate the concepts and let SOA evolve in higher levels of abstraction
Perry covered the topic of Scalable SOA in one of his recent blogs.
Geva quotes Dave Linthicum ("SOA for the real world"):
Making solutions scale is nothing new. However, the SOA technology and approaches recently employed are largely untested with higher application and information and service management traffic loads. SOA implementers were happy to get their solutions up-and-running, however in many cases scalability is simply not a consideration within the SOA, nor was load testing, or other performance fundamentals. We are seeing the results of this neglect now that SOA problem domains are exceeding the capacity of their architectures and the technology in many instances.
While I think that many technical folks are in violent agreement that Web Services and SOA are not necessarily the same thing, the question: what is the alternative approach? remains unanswered
The most important missing piece, however, is the top-down approach to SOA outlined in this article. Most of today's thinking about Web services is bottom up: ''Here's how to build Web services, now let's use them for integration."
Everyone seems to be struggling to define an alternative approach to WS*,
however, very few provide a clear end-to-end definition on how to turn existing
stateful tier-based applications into linearly scalable services. Throwing a messaging-bus at the problem ain't gonna cut it. I would even argue that it
could possibly make things worse.
is a growing class of applications -- specifically those that are
categorized as XTP (Xtreme Transaction Processing) applications -- in which SOA in
its WS* form adds no value due to the fact that the services in this
environment are stateful and need to interact at high speeds, while keeping the
So what should be the platform for High Performance SOA?
There are several emerging frameworks, such as OSGI and Mule, that provide an alternative SOA approach. What is common to these frameworks is the fact that they are POJO-driven, lightweight and highly efficient in terms of performance and footprint. It is therefore not surprising that these frameworks are gaining momentum and are becoming de-facto standards for building high-performance SOA applications. While this initial set of platforms already exists, I think that we still lack the top-down view that Jason was referring to. That is where Space-Based Architecture fits in. In the following reference SBA and SOA I tried to describe how SBA fits into the SOA world as a pattern for turning stateful-tier-based-applications into linearly scalable services.
In his presentation, Scalable
SOA, GigaSpaces VP R&D Guy Nirpaz covers at depth how you can use Space Based
Architecture combined with Spring and potentially OSGi to bridge this gap
and turn your existing tier-based stateful applications into linearly scalable