A framework for the deployment of adaptable web service compositions

摘要

The basic paradigm of service-oriented architectures—publication, discovery, and use—can be interpreted in different ways. Current technologies assume a static and rigid approach: UDDI was conceived with the idea of a centralized repository for service publication and BPEL only supports design–time bindings between the orchestrated workflow and the external services. The trend, however, is towards more flexibility and dynamism. The single centralized repository is being substituted by dedicated repositories that cooperate and exchange information about stored services on demand. Design–time compositions are complemented by mechanisms to allow for the selection and binding of services at runtime. This paper presents the research results of our group in delivering a framework for the deployment of adaptable Web service compositions. The publication infrastructure integrates existing heterogeneous repositories and makes them cooperate for service discovery. The deployment infrastructure supports BPEL-like compositions that can select services dynamically, and also adjust their behavior in response to detected changes and unforeseen events. The framework also provides a monitoring-based validation of running compositions: we provide suitable probes to oversee the execution of deployed compositions. The various parts of the framework are exemplified on a common case study taken from the automotive domain.