SOA in a Virtual World

Wikipedia defines a virtual world as a computer-based simulated environment intended for its users to inhabit it. Often a computer application is a business process made virtual by the use of computer technology. We therefore have to be careful when discussing the virtualization of computer environments as this may imply a virtual virtual reality.

The only example of virtual virtual reality I have seen is in a Futurama episode. It displayed an arcade booth with the label 'Virtual Reality' complete with a player using stereoscopic goggles and wired gloves. It then displayed another arcade booth with man sitting in a simple chair imaging he was wearing stereoscopic goggles and wired gloves. The caption to this booth was "Virtual Virtual Reality".

If we talk about "Virtual SOA" we must be talking about something that is not an SOA at all. Judith Hurwitz comes close to this when she discusses a "Virtualized SOA" in her article "Is virtualization the foundation of SOA?"

Andrew Doble writes about building a virtual SOA without investing in in-house software like an ESB. I would argue that this is in fact legitimate SOA. The only thing "virtual" about Andrew's suggestion is the ownership of the software tools.

Virtualization and SOA however do go together. Judith Hurwitz defines Virtualization as

"a technique for abstracting the physical characteristics of computing resources
in order to more easily leverage hardware systems, applications, operating
systems, networks, graphics, data or storage so they can be repurposed based on
customer need."

I believe that loose-coupling is the foundation of SOA but virtualization in many cases allows the benefits from this loose-coupling to be realised. The basic examples of virtualization are virtual servers, storage area networks and thin client platforms such as Citrix. These provide infrastructure flexibility for the deployment of SOA software. The design of the software for an application written using SOA is not affected. The SOA discipline should make sure that flexible deployment options can be used.

Manufacturers such as IBM are building business around SOA infrastructure. One thing to remember is that you do not need virtualization to build SOA. An SOA application can be built on a single server if you required, although it should also give you the flexibility to distribute this application and take advantage of virtualization options.

I agree with Lorraine Lawson in her posting "SOA and Virtualization: Complex, Fuzzy Ideas That Go Great Together? ". These two concepts mix well. However SOA is from the software development world and virtualisation is from the infrastructure world. We should beware of talking in terms of virtualizing our SOA. Our CIOs may consider we are sitting in a corner thinking we have an SOA when this is just a virtual reality.

Fry from "Futurama" with a virtual Lucy Liu.

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