A Review of Distributed Workflow Management Systems

An increasing number of distributed applications are being constructed by composing them out of existing applications. The resulting applications can be very complex in structure, containing many temporal and dataflow dependencies between their constituent applications. An additional complication is that the execution of such an application may take a long time to complete, and may contain long periods of inactivity, often due to the constituent applications requiring user interactions. In a distributed environment, it is inevitable that long running applications will require support for fault-tolerance and dynamic reconfiguration: machines may fail, services may be moved or withdrawn and application requirements may change. In such an environment it is essential that the structure of applications can be modified to reflect these changes. The C3Ds project has chosen transactional workflow management system technology to provide an execution environment where sets of inter-related tasks can be carried out and supervised in a dependable manner. Transactional workflow systems can be built on top of available middleware technologies. This report presents a brief survey of the state of art in distributed workflow management.