Exception handling framework for workflow automation collaboration

Abstract

To propose a design of a framework in detecting and handling synchronous exceptions, in sending and receiving message, which is the main part in any workflow collaboration. The design is based on the idea of a Gateway Service, which buffers incoming messages in the exceptional case of the messages arriving before the receiving flow is ready. The Gateway Service uses correlations data to deliver the messages to the correct recipients. Moreover, the Gateway Service redirects the service request from a BPEL flow to the location of corresponding Gateway Service where the requested service resides. Although the implementation focuses mainly on cases where messages are added to a service that has already been instantiated, little modification can be added to extend supports to cases where incoming messages create new instances. The service can be well applied to loosely coupled collaborations where most messages are sent in asynchronous patterns. The service itself has been implemented on an event-based web service which spawns new threads at each incoming request, and thus helps dealing with cases where high volume of incoming messages are directed to an instance of a service simultaneously.