Transaction policies for service-oriented computing

Abstract

Service-oriented computing is emerging as a distributed computing model where autonomous services interact with each other using standard Internet technology. In addition to the application-specific functions that services provide (different) services may also support (different) sets of protocols and formats addressing extra-functional concerns such as transaction processing and reliable messaging. This raises the need for services to complement their functional service descriptions with descriptions of extra-functional capabilities, requirements, and/or preferences, which must be matched and enforced for service interactions. In this paper, we address the problem of transactional coordination in service-oriented computing. We argue for the use of declarative policy assertions to advertise and match support for different transaction styles (direct transaction processing, queued transaction processing, and compensation-based transaction processing), and introduce the concept of and system support for transaction coupling modes as the policy-based contracts guiding transactional business process execution. We focus on concrete, protocol-specific policies that apply to relevant Web services specifications. Using transaction policies and our middleware system, we are able to support a reliable SOC environment.