Several years into the SOA era of application and integration development, SOA continues on without a full consensus opinion of what SOA is.
Yet there were plenty of takes on what SOA is at this year's Gartner's Application Architecture, Development & Integration Summit 2008 in Las Vegas, and while the definitions and prognostications on SOA remained diverse, a picture emerges.
It does seem one great trait of SOA is that it is an ongoing process. Its goal is to favorably and repeatedly change development outcomes based around logically partitioned services. It shares this goal with predecessor components, objects and elements of CASE methodologies. But it is different.
The idea that 'one SOA fits all' may be fading. "SOA is integration. It is a strategic initiative," said Gartner analyst Yefim Natis. "You can only do it in parts of a domain where you have control."
One SOA at a time
At last week's Gartner Summit, Natis discussed varieties of SOA, and pointed to the fact that many companies are instituting SOAs, but they are doing so without a singular architectural blueprint for all IT. Some people, according to Natis, are starting to try to federate their 'domain SOAs' based on agreed-to interoperability protocols and transports that span the full organization.
Sometimes, things are best seen in comparison to what they are not. In this example, the 'anti-SOA' may be seen as the mainframe application of yore. Said Natis: "The monolithic application is the other side of SOA." In other words, a SOA is not part of just one app.
Yefim marked defining SOA traits. He said that a SOA is modular, discoverable, shareable, swappable and can be distributed.
The difficulty in SOA-oriented development is that it must achieve real short term business goals while setting the stage for far-reaching architectural objectives. "When you move to SOA there are challenges – it's not all good. Everything you do has dual impact," said Natis. "To get long term strategic benefit requires long term investment."
This past summer was a cold one for SOA, with critics tossing barbs, and denigrating aspects of SOA. Some criticism may be well placed. The Gartner conference brought to mind a paraphrase of an old Elvis Costello song: 'What's so funny about shareable, swappable and modular?' SOA is less a technology than a way to dependably extract business value from technology. It is a journey, and it involves work.