Middleware Support for BPEL Workflows in the AO4BPEL Engine

This paper focuses on middleware concerns in BPEL workflows. When looking at those workflows from the implementation perspective, we observe that they have several BPEL-specific middleware requirements, which are not supported by current WS-* specifications and by most BPEL engines available to date. This demo paper will show the AO4BPEL Engine, which implements a container framework that allows the specification and enforcement of middleware requirements in BPEL processes. A deployment descriptor is used to specify the quality of service requirements of BPEL activities. A light-weight and aspectbased process container is used to enforce those requirements by calling dedicated middleware Web Services. We implemented those middleware Web Services by extending open source implementations of WS-* specifications for security, reliable messaging, and transactions.