A Two-Layered Software Architecture for Distributed Workflow Coordination over Web Services

Abstract

The current state of the art of workflows over Web services employs a centralized composite process to coordinate the constituent Web services. Therefore, the coordinator process is complex, less scalable, and bulky. This paper introduces an architecture and a technique for distributing the centralized coordination logic of traditional workflows by (i) extending the stateless Web services into self-coordinating entities using coordinator proxy objects, and (ii) creating a workflow over these entities by interconnecting them into a distributed network of objects using Web bond primitives. Previously, we have developed Web bond primitives to enforce interdependencies among autonomous entities. We have designed and prototyped our BondFlow system, which provides a platform to configure such distributed workflows, producing coordination components with footprint small enough (around 150 KB) to be executed on a handheld