Deriving Transactional Properties of CompositeWeb Services

Web services have been emerging as a promising technology for business integration. Transactional support to integrated businesses via composing individual Web services is a critical issue. Current Web services protocols (e.g. BPEL4WS) have been proposed to deal with this issue on a strong assumption that each Web service is compensatable for a recovery purpose. It is arguable that Web services composition requires more transactional support beyond the compensation-based solution. This paper looks into the problem of transactional support for composing and scheduling those Web services that may have different transactional properties. The transactional properties of workflow constructs, which are fundamental to the composition of Web services, are thoroughly investigated. The concept of a connection point is introduced to derive the transactional properties of composite Web services. The scheduling issue of composite Web services is also discussed.