Abstract

Workflows are the semantically appropriate composite activities in heterogeneous computing environments. Such environments typically comprise a great diversity of locally autonomous databases, applications, and interfaces. Much good research has focused on the semantics of workflows, and how to capture them in different extended transaction models. Here we address the complementary issues pertaining to how workflows may be declaratively specified, and how distributed constraints may be derived from those specifications to enable local control, thus obviating a centralized scheduler. Previous approaches to this problem were limited and often lacked a formal semantics. 1 Introduction Workflows are composite, semantically appropriate activities that execute in heterogeneous environments. In such environments, extremely common in practice, the challenge is to interoperate properly without violating the autonomy of the components. Workflows address this challenge [5]. Transactional workfl...

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