分布式工作流的动态管理

Dynamic Management in Distributed Workflow

近些年来 ,分布式工作流管理系统设计已经成为计算机学者的研究热点。传统的工作流管理系统大多建立在客户机 /服务器模式上 ,采用集中式的方式。虽然易于实现、维护和管理 ,却存在着系统可扩展性、集成性差 ,产品可靠性、可用性不高 ,安全性能低的显著缺陷。采用分布式策略将工作流系统功能离散化或模块化 ,通过各个模块间的相互协调工作 ,实现预定功能 ,其优点在于能适应大吞吐量的要求、可扩展性高、可靠性强。然而 ,在现代企业管理中 ,由于流程模式改进、客户需求改变等原因迫使流程经常发生变迁。其必须在工作流结构中及时得到反映 ,这就使得动态管理技术在分布式工作流显得必不可少。将从建模、体系结构、运行环境、动态重组几个方面对分布式工作流的动态管理技术进行介绍和探讨。

Designing a distributed WfMS(Workflow Managemen System) has become a topic with tremendous research interests in recent years. Unlike traditional C/S WfMSs that execute only at a single site which lead to bad scalability, reliability and security, a distributed WfMS divides workflow into different modules. These modules can run in more sites and cooperate each other. It allows the execution of a workflow instance to be governed by more than one server so as to achieve availability, scalability, reliability and efficiency. In a distributed workflow, it's inevitable that management of large enterprise will require support for dynamic management because,the improvement of workflow model, workflow user requirements may be changed. It's essential that the structure of workflow should be modified to reflect such changes in such an environment. In this paper we discuss three aspects of dynamic management of distributed workflow: workflow modeling, workflow execution environment, dynamic reconfiguration to illustrate feathers of dynamic management of distributed workflow.