A distributed workflow management model for grid middleware

Workflow management enables grid service composition and user collaboration in grid middleware, it includes the workflow of grid service invoking and data exchanging among services. Because of the large requirements of grid service composition, it's necessary for the workflow management to be scalable in many grid application systems. This paper proposes a distributed workflow management model for grid middleware, it is comprised of three modules including workflow definition tool (WDT), workflow balancer (WB), workflow execution engine (WEE) and defines the interfaces between workflow management and other grid components. Firstly, WDT composites grid services into workflow service, secondly WB dispatches workflow services and workflow job requests, thirdly WEE is up to the execution of workflow jobs. Furthermore, it describes the interfaces between workflow management and related grid components, such as job management, information service and grid portal. Also it divides the interfaces into WEE management, workflow service management and workflow job management. With the implementation and experiments of this model for Chinese education and research, its support platform middleware, its usability is verified through the usage of workflow tools in image processing scenario, its scalability and load balancing ability are proved in workflow scheduling test.