EDA scenario
This scenario shows how the event processing business pattern for event-driven architecture integration described in Chapter 1 can be implemented.
Implementing the event processing business pattern
As shown in the following diagram, the event processing business pattern can be implemented using a Complex Event Processing (CEP) engine, which is controlled by an ESB.
Trigger:
An event occurs and is placed in a queue by the source system.
Primary flow:
1. An event-driven consumer building block removes the messages or events from the queues using an appropriate JMS adapter, and forwards them to the CEP engine.
2. The CEP engine uses a specific query language to identify the events that are of interest, and enables events to be, for example, filtered, correlated, and aggregated.
3. The CEP engine sends the events that it has identified, in the form of messages, to the ESB endpoint. This ensures that the events are forwarded as messages to a web service through SOAP.
4. The events that...