Who needs to think about SOA in this age of cloud computing? Heck, who even remembers what SOA stood for?
SOA experts do, for one, and cloud experts do for another. And what many-not all, but many-are saying is you are, in effect, building a service-oriented architecture by default when you engage with the cloud.
When you implement cloud computing without understanding that, you're going to create problems down the road, warns David Linthicum, CTO of Blue Mountain Labs and an IT veteran who wears many hats, including SOA and cloud expert.
Linthicum calls this approach a "Franken-SOA" and says the problem with it is you'll wind up with an ill-conceived architecture that will be difficult to manage and change:
In Franken-SOA, there is no governance, no identity management, no service management and no service discovery. It's like driving an Indy car without a steering where. It's very powerful, but you will hit the wall-quickly.
It's an avoidable mistake, he writes, if you plan and put some architectural effort into it.
The smart move would be to approach cloud as you would any internal IT resource-with forethought and a plan. But where's the fun in that? Why learn from the mistakes of others when you can create the same mistakes for the very first time-again.
But, you may be thinking, "Is this just another thinly-veiled attempt to hype up SOA again?" And, truth be told, even in the tech community, there are SOA doubters who say it was just hype anyway. InfoQ quotes VMware's Rod Johnson as calling SOA "very sound at an architectural practice level, but in terms of selling product, it was really an artificial, marketing created, concept." Johnson goes on to say that cloud has more "substance behind it."
I suspect a lot of other tech experts would disagree. The same InfoQ article asked a virtual panel for their thoughts on SOA and cloud. The panel included Linthicum; JP Morgenthal; Rob High of IBM; Miko Matsumura, formerly of Sun, but now with SoftwareAg; and William Vambenepe, an architect with Oracle, about the cloud/SOA connect. I'll grant you, all have a vested interest in SOA, with Linthicum and Morgenthal being SOA/cloud experts and, obviously, the vendor members all representing companies with SOA products. But, I think you'll find their reasoning extends beyond mere marketing when you read the full article. They actually make a good case for how SOA can make the cloud more accessible, more useful and more powerful for those who understand how they work together.
Of course you can have cloud without SOA. But as Vambenepe explained, cloud without SOA has less potential:
When bringing business applications to a cloud environment, you need to be able to decompose them in manageable units both from an interaction perspective (How they relate with one another, which is what SOA focuses on) and an operational perspective (where Cloud Computing brings more formalism and automation). If you've already done the work in the context of a SOA effort, and you've done it on top of an infrastructure that is SOA-aware, then you're probably in good shape with regards to operational decomposition. If, on the other hand, you don't efficiently control the interactions and dependencies of your application components, then you'll have to do it now or your move to Cloud will really just be a move to virtualization. You'll get some consolidation benefits, but not a real Cloud Computing environment.
And that is the bottom line about SOA and cloud: It's about potential. Use cloud by itself and you get one thing; add SOA and you get so much more.
Hollis Tibbetts, a middleware expert who writes for ebizQ, explains, there's SOA and there's cloud and there's the intersection of SOA and cloud.
"That intersection is a very exciting place to be," Tibbetts writes. "Enterprises AND software companies seeking competitive advantage through IT innovation should be aware of this technology shift and actively defining strategies for capitalizing on it."