An Operational Approach to BPEL-like Programming

摘要

Web services have become more and more important during these years and BPEL4WS (BPEL) is to be a stan- dard for the web services composition and orchestration. It contains several distinct features, including the scope- based compensation and fault handling mechanism. In this paper, we formalize an operational semantics for BPEL, which provides the precise understanding of the language. In order to explore program equivalence, bisimulation is in- troduced for BPEL programs in the form of two-layer struc- ture. A set of algebraic laws is studied, which includes sev- eral BPEL featured laws. These algebraic laws are verified via the two-layer bisimulation. This reflects that our bisim- ulation is a practical approach to explore program equiva- lence for web services. Keywords: Web Services; BPEL; Compensation; Fault Handling; Operational Semantics; Bisimulation; Algebraic Semantics