A Distributed Execution Environment for Large-Scale Workflow Management Systems with Subnets and Server Migration

Abstract

If the number of users within a workflow management system increases, a central workflow server (WFserver)and a single local area network (LAN) may become overloaded. The approach presented in this paper describes an execution environment which is able to manage a growing number of users by adding new servers and subnets. The basic idea is to decompose processes into parts which are controlled by different WF-servers. That is, during the execution of a workflow instance its execution (step) control may migrate from one WF-server to another. By selecting the appropriate physical servers (for hosting the WF-servers) in the appropriate LANs, communication costs and individual WF-server workload can be reduced significantly.