一种面向软件体系结构的动态重配置方法*

通过在整个软件生命周期建立开发模型,研究了当前软件工程与实际需求之间差异。利用基于XML的中间脚本,提出一种事务处理软件开发模型,实现用户功能需求到表单流、事件流和数据流的转换,动态重配置出不同应用的事务处理软件。建立了企事业信息综合事务处理系统开发平台,分析了平台体系结构和中间脚本,表明可以根据业务变化进行整个系统功能重组而不需要编写一句程序,验证了该模型的可行性和有效性。     

WCA：一种面向Web系统的通用组件架构

随着Web应用的爆炸式增长,面向Web的工程理论和方法研究得到了广泛的重视.本文针对Web工程应用中存在的通用架构设计和组件重用等问题,提出了一套灵活、可扩展的Web组件架构模型WCA,以及与之相辅的一套Web系统分析、设计、编码与测试的方法体系.     

面向Web服务的管理体系架构

Web服务作为一种新型的分布式计算和处理的技术,为实现大范围的信息系统之间的通信和交互提供了条件.根据Web服务本身的特点,提出了一个面向Web服务的管理体系架构.并举例说明如何应用此架构解决实际应用中Web服务管理的问题.     

一种Web应用框架的研究与实现

软件框架是目前产业界实现大型软件快速开发的关键,也是学术界研究的热点.文中分析了Web应用三层架构的实现方式及其特点,提出了一种新的Web应用框架.该框架采用"面向接口"的设计思想,通过构建业务逻辑接口层实现了表示层和业务功能层之间的松散耦合,通过构建数据访问接口层实现了业务功能层和数据存储层之间的松散耦合;以某大型制造企业的工时管理系统中用户登录功能模块为例,详细阐述了采用此框架构建Web应用的具体过程.该框架可为有效实现基于Web的应用软件的开发提供帮助.     

动态Web技术架构及其性能分析

本文对三项动态Web技术进行了性能研究,包括PHP、Java Servlet、以及EJB。用TPC-W负载对三种技术架构进行了性能测试。实验结果显示,对于中小规模的动态Web系统,PHP技术表现出良好的性能。Java Servlet技术在性能上比PHP稍微差一些。但是当数据库加锁冲突加剧的时候。可以利用Java的同步机制减少这种冲突。提高系统吞吐量。另外,当Web服务器成为系统瓶颈时。可以把Servlet执行引擎迁移到其它机器,通过负载均衡达到提高性能的目的。EJB技术在所有的测试中,都获得最差的性能。但是通过不同版本的EJB服务器的性能比较,我们发现新版本的EJB容器在数据库存取上做了大量优化。获得了可观的性能提高,EJB技术具有丰富的基础服务,其架构灵活,逐渐成为企业计算的现实选择。     

MVC架构及其在Web应用开发中的应用

介绍了MVC架构及其利用Struts在Web应用程序中的实现,从系统架构的角度,提高了Web应用程序的可扩展性和可维护性。     

基于ASP.NET的Web应用系统架构探讨

提出了一种基于ASP．NET开发方式的四层架构的Web应用系统构造思想。其基本内容是：将面向对象的UML建模与Web应用系统开发相结合，将整个系统分成适合ASP．NET开发方式的应用表示层、业务逻辑层、数据访问层和数据存储层四层结构。以此方式构造的Web应用不仅达到了代码组织结构清晰明朗、高重用性、适用性，易于维护和移植的目标，而且可以提高web应用系统的开发速度。解决了目前大型Web程序开发中，代码适用性、重用性差，及难于维护和移植的问题。     

一种动态Web页面缓存技术

1 引言信息多样性的驱动以及互联网个性化趋势,使得越来越多的动态内容被引入Internet。动态页面的实现主要是通过CGI(Common Gateway Interface)或类CGI程序(如:ASP、JSP、PHP、Perl等服务器端嵌入式脚本)在服务器上根据客户端GET或POST方法发来的消息作为参数,并也可与后台数据库交互,动态生成HTML文档。所以,这些临时自动生成的页面“总是”被浏览器认为是最新的。故此,目前大多数的缓存系统都无法对动态页面进行缓存。然而由于CGI程序本身或其访问的数据库并不总是变化的,因而没有必要每次都要向原始服务器发送请求。     

一种Web应用测试数据生成与组织架构

随着web应用的不断普及,web应用软件的测试越来越重要。本文针对web应用的测试数据生成和组织结构问题,提出了一种元模型驱动的数据池技术,并实现了一个测试数据生成与组织框架。该框架依据web页面上的输入域类型、输入变量的数据类型以及实例化约束条件,支持手工或自动产生测试数据。     

面向服务架构的全球数字制造技术

本文通过对全球数字制造的内涵及在此环境下实现敏捷制造和构建动态联盟所需技术条件的分析,根据对全球数字制造系统原型研发的经验,提出了在这种环境下基于WebService技术构建敏捷制造和动态联盟的一种面向服务的架构,并通过简单的实例与现实世界中的服务进行对比,描述了此架构的使用流程。     

Architecting and implementing distributed Web applications using the graph‐oriented approach

This paper presents a graph‐oriented framework, called WebGOP, for architecture modeling and programming of Web‐based distributed applications. WebGOP is based on the graph‐oriented programming (GOP) model, under which the components of a distributed program are configured as a logical graph and implemented using a set of operations defined over the graph. WebGOP reshapes GOP with a reflective object‐oriented design, which provides powerful architectural support in the World Wide Web environment. In WebGOP, the architecture graph is reified as an explicit object which itself is distributed over the network, providing a graph‐oriented context for the execution of distributed applications. The programmer can specialize the type of graph to represent a particular architecture style tailored for an application. WebGOP also has built‐in support for flexible and dynamic architectures, including both planned and unplanned dynamic reconfiguration of distributed applications. We describe the WebGOP framework, a prototypical implementation of the framework on top of SOAP, and a performance evaluation of the prototype. The prototype demonstrated the feasibility of our approach. Results of the performance evaluation showed that the overhead introduced by WebGOP over SOAP is reasonable and acceptable. Copyright © 2003 John Wiley & Sons, Ltd.     

利用构件框架技术构造高度灵活的分布式中间件

为了构造灵活的中间件,本文基于现有中间件标准的计算模型和工程模型,从所面临的需求或挑战的来源出发,系统化地分析了这些挑战对于中间件实现所造成的影响和相应解决方案应该满足的特征,并采用构件和构件框架技术,提出了一个实现框架,以满足各种灵活性需求.     

An Approach for Recovering Distributed System Architectures

Reasoning about software systems at the architectural level is key to effective software development, management, evolution and reuse. All too often, though, the lack of appropriate documentation leads to a situation where architectural design information has to be recovered directly from implemented software artifacts. This is a very demanding process, particularly when involving recovery of runtime abstractions (clients, servers, interaction protocols, etc.) that are typical to the design of distributed software systems. This paper presents an exploratory reverse engineering approach, called X-ray, to aid programmers in recovering architectural runtime information from a distributed system's existing software artifacts. X-ray comprises three domain-based static analysis techniques, namely component module classification, syntactic pattern matching, and structural reachability analysis. These complementary techniques can facilitate the task of identifying a distributed system's implemented executable components and their potential runtime interconnections. The component module classification technique automatically distinguishes source code modules according to the executables components they implement. The syntactic pattern matching technique in turn helps to recognise specific code fragments that may implement typical component interaction features. Finally, the structural reachability analysis technique aids in the association of those features to the code specific for each executable component. The paper describes and illustrates the main concepts underlying each technique, reports on their implementation as a suit of new and off-the-shelf tools, and, to give evidence of the utility of the approach, provides a detailed account of a successful application of the three techniques to help recover a static approximation of the runtime architecture for Field, a publicly-available distributed programming environment.     

一种面向图的分布式软件动态配置和容错方法

提出一种新的方法，通过动态配置对基于组件的分布式软件的容错提供支持。此方法采用面向图的GOP编程模型，将整个分布式软件的体系结构用一张逻辑图来描述，系统的动态配置可以通过执行图上预定义的一组操作来完成。检测到故障或异常的时候实施这种动态配置能够支持系统的容错。文中描述了此方法的基本模型、系统结构和基于CORBA的原型实现。     

Fault Management in Distributed Systems: A Policy-Driven Approach

Managing the availability and performance of a distributed system involves monitoring the behavior of the system, identifying system problems, and correcting those problems. Each of these tasks requires some expertise, such as an understanding of the mechanics of the underlying system components. As the size and complexity of these systems increases, and the number of distributed applications executing on these systems increases, managing the availability and performance of distributed systems becomes more difficult. Little research has focused on embedding systems management expertise into a management application for a distributed system. In this paper we describe a rule-based management application for a commercially available distributed computing environment that is capable of monitoring the distributed system, detecting system service-related performance and availability problems, and generating corrective actions to correct the problems.     

分布式软件体系结构中组件依赖的描述

分布式软件的动态配置及软件体系结构中的一个重要问题是对组件依赖的理解和描述。该文采用的方法提供了精确描述组件交互的基础,展示了分布式系统组件间的拓扑关系,进而描述了软件体系结构。该方法还对组件测试提供了有力支持,它的突出优点是用一种方法来描述体系结构并支持软件测试。     

The UM-MAIS Methodology for Multi-channel Adaptive Web Information Systems

Multichannel Adaptive Web Information Systems (WISs) are emerging as a new class of information systems, characterized by their powerful use of mobility and context-awareness. Different methodologies have been proposed so far for the analysis and design of Multichannel Adaptive WISs, specifically focused on the front-end layer or the back-end layer, but no methodology has aimed to cover all the lifecycle and to design all the components that characterize Multichannel Adaptive WIS. This paper fills such a gap, by presenting UM-MAIS (Unified Methodology for Multichannel Adaptive Information Systems), a new methodology that capitalizes on well-established existing methods. It supports the analysis and design of the various components of Multichannel Adaptive WISs (including the user’s experience) in a comprehensive and unified manner with special emphasis on context modeling, personalization, and adaptation.     

基于软件体系结构的Web应用自适应

随着互联网的迅速发展,Internet上的Web应用大量涌现.然而传统主要依靠管理人员人工配置和维护系统的方式由于不断变化的环境和需求而显得有所不足.本文在相关工作的基础上,提出一种基于软件体系结构构建自适应Web系统的技术方案,该方案具有非侵入式设计和自适应相关组件具有可恢复能力的特点.同时,本文也实现了一个自适应系统原型来说明这个方案及其效果.