The Web Services-BusinessActivity-Initiator (WS-BA-I) Protocol: an Extension to the Web Services-BusinessActivity Specification

The Web services transaction protocol family includes the WS-atomic transaction and the WS-business activity specifications in order to carry out distributed transactions in a Web services (WS) environment. The WS-atomic transaction specification defines all necessary interfaces to carry out transactional work. In contrary, the WS-business activity specification for long-running transactions intentionally left the interface between initiator and coordinator undefined. This allows vendors to integrate WS-business activity coordinators into their business process engines. However, it requires proprietary protocols between initiator and coordinator. We propose an extension protocol to the WS-business activity specification that explicitly defines this interface between initiator and coordinator. This extension allows coordinators and initiators from different vendors to interoperate transparently. Accordingly, participants no longer need to trust an initiator-selected and likely initiator-run coordination service, but may use commonly trusted, third-party coordination services.