Event-driven response architecture for event-based computing

Service-based computing is rapidly replacing the more-traditional approaches to architecting distributed systems. The critical advantage of service-based architectures is that they require only a specification of protocol, and not of API. As such, they engender a significantly looser coupling than prior techniques, thus facilitating seamless collaboration across systems and across administrative domains. A Service-Oriented Architecture (SOA) is a middleware platform that provides a servicebased computing environment. The "publishfind-bind" paradigm at the core of SOA enables the development of service-provision software separately from the development of serviceconsumption software. Closer observation of each aspect in this paradigm reveals that significant developer involvement is still required to assist the interaction between service provider and consumer. Developers of service-consumer software make the decision to employ a set of service providers at development time. Some SOAs provide facilities to programmatically search, bind, and even invoke services dynamically. However, it is still assumed that knowledge of both service providers and the service provided is known at development time, or the client must supply Copyright  2005 Vijay Dheap, Dr. Paul A.S. Ward, and IBM Corp. Permission to copy is hereby granted provided the original copyright notice is reproduced in copies made. highly-detailed information about services they wish to use. This severely limits the possibility of dynamic run-time interactions among service providers and service consumers. In this paper we introduce EDRA, the EventDriven Response Architecture for service-based computing. EDRA is a software framework that provides an infrastructure to dynamically select client-relevant service providers during run-time. Information services selected by EDRA on behalf of clients may send notification events in case of changes in the service. In such cases, our runtime will automatically process the notification based on a selection of user-choice, system defaults, and available action services. We have implemented a prototype of our framework, and show its operation in the domain of airline services.