Blind-date Conversation Joining

In service-oriented applications, service providers and their clients can engage in conversations to exchange the data required to achieve their business goals. In this paper, we focus on a particular kind of conversation joining, which we call blind-date, where a client may join a conversation among multiple parties in an asynchronous and completely transparent way. Indeed, the client can join the conversation without knowing any information about it in advance. More specifically, we show that the correlation mechanism provided by orchestration languages enables the blind-date conversation joining strategy. To demonstrate the feasibility of the approach, we provide an implementation of this strategy by using the standard orchestration language WS-BPEL. Moreover, to clarify the run-time effects of the blind-date joining, we formally describe its behaviour by resorting to COWS, a process calculus specifically designed for modelling service-oriented applications. We illustrate our approach by means of a simple example and a more realistic case study from the online games domain.