Event Based Approach for Web Services Composition

The success of the Internet and the ongoing globalization led to a demand for new solutions to meet the requirements for ITsystems. The paradigm of service-oriented and event-driven architecture with fine grained and loosely coupled services tries to cope with those needs. Service Oriented Architecture (SOA) and Event Driven Architecture (EDA) are two acknowledged architectures for the development of business applications and information systems, which have evolved separately over the years. Today both architectures are acknowledged, but their synergy is not. There are numerous benefits of having an architecture that supports coexistence between operations and events, and composition of services based on operation invocation and event triggering. As part of our ongoing research work, we have tried to analyze in this paper, the basic design of Event based systems, issues that have to be addressed when event based approach is used for composing and coordinating web services. Then we have specified the techniques available that handle these issues, and gave a comparative study on these techniques. Finally we have attempted to sort out the unhandled/ partially handled issues that could be addressed as part of our research.