Event-driven architecture
At the Application Integration and Web Services Summit last May, Gartner analyst Roy Schulte called "event-driven architecture" the "next big thing." Indeed, he predicted more than 67% of new large-scale application systems would "emit" business events by 2008. It was an intriguing prediction.
"Event-driven design is a fundamental requirement of pervasive computing and agility," he explained. "Events are based on notification, a decoupled type of communication that is more scalable and flexible than loosely coupled or tightly coupled interactions. Imagine a world where every new application emits a continuous stream of messages that record every significant action, regardless of whether the use of that data is known when the application was built. Imagine that routine documents, files and messages sent through the enterprise network and Internet are automatically scanned to extract meaningful data without having any impact on the sending or receiving applications."
Are you done imagining? Don't quit just yet. "Imagine that sensors are placed strategically around the enterprise to observe what is happening in the physical world outside of IT. What could a business person accomplish if he or she could tap into this wealth of information in a timely fashion? What problems could be anticipated and headed off before they caused damage? What opportunities for maximizing the value of human effort and capital would be created? People often say, 'If only I knew then what I know now,' but in many cases they could have known 'then' if they had had access to data that already existed. To accomplish this level of awareness, low-impact methods for collecting event data must be implemented; networks must have more throughput; and intelligent listener agents must be installed in the network to evaluate event messages, discarding those not needed and summarizing low-level observations into higher-level 'complex' events suitable for presenting to people or triggering automated follow-up actions."
As Schulte sees it, "Event-driven design will be 'the next big thing' in business architecture and in IT because it brings unprecedented power to support dynamic and multifaceted business processes. Events will complement, not replace, services in a service-oriented architecture. The agile enterprise will be service-oriented in some places and event-driven in others."