Organizations trying to become an agile, real-time enterprise often don’t notice that most of their critical business events lie dormant, locked within the safe confines of their complex operating systems. Event-driven architecture offers the promise of unlocking business potential in a world where business processes and their dependencies on business events occur without latency. Imagine a corporation where:
- Any important business event can be easily, efficiently, reliably identified, captured, and published to the corporate message bus without expensive, risky application re-engineering.
- The information describing the events proceeds through the enterprise with great potential to affect numerous business units that derive unique value in subscribing to those events.
- Business analysts can dynamically configure the entire system easily and safely without recourse to complex technical implementation tasks.
You’re imagining a corporation that has successfully implemented event-driven architecture.
Since a business event loosely constitutes a change or an act in a business state, the information flow is asynchronous or push-oriented, originating from the source of the event and published out to the enterprise. This allows for a new, more virtual view of the corporate enterprise that expands beyond the hardened corporate boundary to encompass every other business entity that could be touched by event-driven business processes.
EAI: GENESIS OF EVENT-DRIVEN ARCHITECTURE
Multi-point human data entry, phone, fax, mail, and a host of other latency-flawed technologies support traditional methods of processing across enterprise applications. This involves linear batch processing and redundant, paper reporting, data entry, and manual exception processing that occurs in concert with disparate business units. Zerolatency, in reality, becomes days and perhaps weeks, so that information between business units is rendered irrelevant. Because it can improve upon these latency-flawed systems, enterprise application integration (EAI) has become a mainstream discipline that’s attractive to most CIOs.
Initially seen as a way of synchronizing important data under the control of various applications, EAI has evolved into a platform to streamline business processes and improve efficiency by eliminating the friction that occurs inside businesses as a consequence of data inconsistencies. Furthermore, with the advent of ubiquitous Internet connectivity, it has been used to ensure that key applications have the accuracy necessary to encourage confident use by customers, suppliers, and partners.
Most integration initiatives have been pull- or request/reply-oriented. This means that timing of the integration process occurs under the control of the integration platform itself. The integration platform requests or pulls information from the underlying application systems to have the information available to enrich a target application system. However, the pull process occurs at predefined intervals. Such initiatives have delivered considerable business value but are only the first step in making organizations more agile. To further reduce friction inside the business process, business and integration processes must often be triggered by events occurring in the underlying systems in near real-time. This approach is known as event-driven integration. An integration strategy that embraces an event-driven approach can deliver consistent information across the enterprise far more rapidly. Often, event-driven integration is the only way to ensure consistency since many events have meaning only if captured at the precise moment they occur.
An often-cited example is that of stock prices. Repeatedly pulling a quote from an underlying system that tracks the price movements is almost guaranteed to miss certain important price changes due to float—the time between initially retrieved information and its availability for processing. If a price moved from $1.87 to $1.88 and back to $1.87 between invocations of the price quote request from the integration platform, for all intents and purposes, the price movement never occurred from the perspective of the integration platform. One can think of many other examples of such time-sensitive events.
For the largest organizations around the world, implementing a strategy that depends on event-driven integration would mean capturing events that occur within mainframe systems. The IBM zSeries mainframe remains the primary processing platform for the transactional and batch workload of the Fortune 500. Changing the billions of lines of proprietary programming that underpin these transactional and batch applications isn’t for the faint-hearted. Implementing event-driven integration in support of mainframe events requires a non-invasive approach if it’s to have any chance of success.
THE VALUE OF BUSINESS EVENTS