Correlation Patterns in Service-Oriented Architectures

Abstract. When a service engages in multiple interactions concurrently, it is generally required to correlate incoming messages with messages previously sent or received. Features to deal with this correlation re-quirement have been incorporated into standards and tools for service implementation, but the supported sets of features are ad hoc as there is a lack of an overarching framework from which their expressiveness can be evaluated. This paper introduces a set of patterns that provide a basis for evaluating languages and protocols for service implementation in terms of their support for correlation. The proposed correlation pat-terns are grounded in a formal model that views correlation mechanisms as means of grouping atomic message events into conversations and pro-cesses. The paper also provides an evaluation of relevant standards in terms of the patterns, specifically WS-Addressing and BPEL, and dis-cusses how these standards have and could continue to evolve to address a wider set of correlation scenarios.