动态分布式系统中多层次配置文件的形式描述及管理

FORMAL SPECIFICATION AND MANAGEMENT OF MULTI LAYERED CONFIGURATION FILE IN DYNAMIC DISTRIBUTED SYSTEMS

介绍了分布式程序设计模型ＥｘＧＯＭ（ＥｘｔｅｎｄｅｄＧｒａｐｈＯｒｉｅｎｔｅｄＭｏｄｅｌ）中一种新型的多层次配置文件的结构及相关的配置描述．基于树型结构的多层次的配置文件为分布式系统的动态重配置提供了灵活、清晰的结构和丰富的基于图结构的配置操作．一个树型结构的分布式应用的配置文件包含若干个处于不同层次的深度不大于２的子树．这些子树通过装配规则可装配成一棵大树，它就是分布式应用程序的逻辑图结构．通过配置文件修改Ａｇｅｎｔ，用户可在线、实时地修改各层配置文件。

The tree structured multi layered configuration file supplies a flexible and clear structure, and various graph oriented configuration operations. It is a fundamental part in ExGOM (Extended Graph Oriented Model, a distributed programming model supporting dynamic configuration) to support non deterministic dynamic configuration, including plannable dynamic configuration and unpredicted (non preplanned) dynamic configuration. The configuration file in a tree structured distributed application is composed of several multi layered sub trees with depth not larger than two. These sub trees are configured through configuration rules into a big tree, which is the logical graph construct of the distributed application. Using 'Edit Agent', users can make on line changes of different layers of configuration files, thus triggering dynamic configurations. This paper introduces such a new, multi layered configuration file and relative configuration specification employed in ExGOM.