Event-driven modeling and testing of real-time web services

A service-oriented architecture (SOA) for web applications is often implemented using web services (WSs) and consists of different operations the executions of which are perceived as events. The order and time-appropriateness of occurrences of these events play a vital role for the proper functioning of a real-time SOA. This paper presents an event-based approach to modeling and testing of functional behavior of WSs by event sequence graphs (ESG). Nodes of an ESG represent events, e.g., “request” or “response”, and arcs give the sequence of these events. For representing parameter values, e.g., for time-out of operation calls, ESG are augmented by decision tables. A case study carried out on a commercial web system with SOA validates the approach and analyzes its characteristic issues. The novelty of the approach stems from (i) its simplicity and lucidity in representing complex real-time web applications based on WSs in SOA, and (ii) its modeling that considers also testing and thus enables a comfortable fault management leading to a holistic view.