一种中间件服务容错配置管理方法

提出一种基于运行时刻软件体系结构的容错管理方法,支持开发者和管理员针对不同中间件服务失效定制合适的故障检测和修复机制.首先,运行时刻软件体系结构自动构造构件依赖视图和错误传播①视图,为理解和分析整个系统的可靠性提供全局视图;然后,操作运行时刻软件体系结构配置容错机制;最后利用AOP技术将容错机制插装到中间件中,使其具备指定的容错能力.上述过程在一个可视化工具的辅助下半自动实施,并在J2EE中间件上得到验证.     

基于软件体系结构的反射式中间件研究

Internet为分布应用提供了一种开放、动态的运行环境,这要求分布应用的主要基础设施中间件能够支持运行时查看并调整平台内部状态和行为,由此产生了反射式中间件.目前的反射式中间件研究与实践存在3个不足:注重系统局部或单个实体的反射而缺乏全局视图;注重中间件平台内部功能的反射,而对上层应用的反射不够;集中于CORBA平台,而对J2EE平台的反射性研究较少.介绍了一个反射式的J2EE应用服务器PKUAS.基于构件化的平台内部体系结构,PKUAS引入软件体系结构作为全局视图以实现反射体系对系统整体的表示和控制,作为J2EE应用服务器,PKUAS可反射底层平台以及上层EJB构件.同时,以PKUAS实时监控工具为例,探讨了如何利用基于软件体系结构的反射体系管理整个系统,并给出了PKUAS与其他几种反射式中间件的比较.该工作有效地解决了现阶段反射式中间件研究的不足,提高了反射式中间件的实用性.     

软件体系结构驱动的运行环境

由于软件体系结构以隐性的方式存在，结构的问题被传播到平台内，运行时软件体系结构不能在应用层次上被观察和控制，系统难以联机动态演化．在现有的中间件平台之上设计了一个面向应用、开放的、软件体系结构驱动的分布式远行环境SADRE（Software Architecture—Driven Runtime Environment），软件体系结构在可运行系统中以一类实体显性地表示,体系结构描述作为核心元素被整个分布式运行环境共事，成为系统调度、通信的依据．从而驱动用户应用的运行．SADRE为灵活的动态体系结构提供了良好的支持，提高了系统的柔性和扩展性．     

一种发现运行时软件体系结构的方法

运行时软件体系结构能够准确描述目标系统的真实状态和行为,对指导软件的维护和演化起着重要的作用。本文提出了一种发现运行时体系结构的方法,利用系统实现与体系结构风格之间的对应关系,定义了一种基于规则的转换映射;将收集到的底层系统事件解释成体系结构层面的操作,从而可获取运行时体系结构视图;通过一个即时通信系统实例说明了该方法的可行性。     

基于反射和连接件的SA动态演化研究

使用反射机制感知软件系统的结构与运行状态,提出了一种基于知识规则、直接对连接件进行操作的SA动态演化方法,消除了SA动态演化的不一致性,提高了效率.该方法使用代数表达式简化了演化日志,提高了演化可跟踪性。     

基于通用连接器模型的复合构件的组装

基于构件的软件体系结构(SA)由构件与连接器组成，连接器作为构件间的交互实体在SA中扮演着重要角色。现有的连接器模型只能支持特定软件体系结构风格的组装，该文针对构件组装的核心问题：构件间交互的不匹配，采用复合构件组装的方法，提出一种通用连接器模型用以对不同连接器模型进行描述。给出4种复合构件组装机制及各种机制的组装方式，并对复合构件进行扩展，使其具有动态性，能较方便地实现动态体系结构。     

Technical framework for Internetware: An architecture centric approach

Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program （973）, researchers in China have developed an architecture centric technical framework for the definition, incarnation and engineering of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc.     

Using architecture models for runtime adaptability

Every software system has architecture. The architecture strongly influences the software system's properties, including maintainability and runtime properties such as performance and reliability. By describing the architecture in models, we can make the architecture explicit. Developers typically use software architecture models at design time to capture the significant decisions about a software system's organization and to describe and establish a common understanding about the system's abstract properties. In the MADAM (mobility- and adaptation-enabling middleware) project, we aim to facilitate adaptive application development for mobile computing. We follow an architecture-centric approach where we represent architecture models at runtime to allow generic middleware components to reason about and control adaptation.     

ABC:基于体系结构、面向构件的软件开发方法

基于构件的软件复用和开发被认为是提高软件开发效率和质量的有效途径,并在分布式系统中得到了广泛的应用.但是,目前的软件构件技术主要还是着眼于构件实现模型和运行时互操作,缺乏一套系统的方法以指导整个开发过程.近年来,以构件为基本单元的软件体系结构研究取得了较大的发展.它通过对软件系统整体结构和特性的描述,为面向构件的软件开发提供了一个自顶向下的途径.介绍了一种以软件体系结构为指导,面向构件的软件开发方法,试图为基于构件的软件复用提供一种有效的解决方案.这种方法主要是将软件体系结构引入到软件开发的各个阶段,作为系统开发的蓝图,利用工具支持的自动转换机制缩小从高层设计到实现的距离,而后在构件平台的运行支持下实现自动的系统组装生成.     

基于不动点转移的SA动态演化模型

构造性和演化性是软件的两个基本特性．而软件演化包括静态演化和动态演化两个方面．动态演化更为复杂，这种复杂性决定了．对动态演化的研究首先应从宏观层面人手．软件体系结构SA作为软件的蓝图和支撑骨架．为人们宏观把握软件的动态演化提供了一条有效的途径．该文描述了构件——连接件组成的SA动态语义网络模型．分析了SA动态语义网络模型中的浸润过程．给出基于不动点的浸润过程收敛的判定，提出了邻接矩阵过滤和原子过滤的概念，阐明了基于邻接矩阵原子过滤的SA动态语义网络浸润步的原子性．指出SA动态演化过程可用一系列邻接矩阵原子过滤在时刻上相继的逻辑衔接来描述．最后给出了两个层面上对SA动态演化波及效应的分析方法．为基于矩阵变换的SA动态演化的进一步研究和计算机自动量化描述奠定了基础．     

适用于动态软件体系结构的扩展的Z描述语言

动态软件体系结构语言已成为描述复杂软件体系结构的重要工具,然而许多描述语言都是静态的,并不能对动态软件体系进行描述。为此,对经典Z描述语言进行扩展,主要通过对构件、连接件和它们的添加以及删除来达到动态演化的目的。实例分析表明了这种扩展的可行性。     

A software architecture centric engineering approach for Internetware

As a new software paradigm evolved by the Internet, Internetware brings many challenges for the traditional software development methods and techniques. Though architecture-based component composition (ABC) approach is originated in the traditional software paradigm, it supports the engineering of Internetware effectively due to its philosophy, rationales and mechanisms. ABC has three major contributions to the en- gineering of Internetware in detail. First, the feature oriented domain modeling method can structure the “disordered”“software entities” to “ordered Internetware” bottom-up in the problem space. Second, the architecture centric design and analysis method can support the development of self-adaptive Internetware. Third, the component operating platform is a reflective and self-adaptive middleware that not only provides Internetware with a pow- erful and flexible runtime infrastructure but also enables the self-adaptation of the structure and individual entities of Internetware.     

A software architecture centric self-adaptation approach for Internetware

Being one of the basic features of Internetware, self-adaptation means that the software system can monitor its runtime state and behavior and adjust them when necessary according to pre-defined policies. Focusing on the three fundamental issues of self-adaptation, including the scope, operability and trustworthiness, a software architecture （SA） centric approach for Internetware＇s self-adaptation is presented in this paper. All of the self-adaptive actions, i.e. monitoring, analyzing, planning and executing, are performed based on SA. In detail, runtime state and behavior of Internetware are represented and changed in the form of runtime soft- ware architecture. The knowledge for self-adaptation is captured, organized and reasoned in the form of SA so that automatic analysis and decision-making are achieved.     

嵌入式RFID中间件的设计与实现

对基于嵌入式系统的RFID中间件进行了研究.该中间件架构在多个针对嵌入式系统的开源软件系统平台之上,系统中各组件通过环形缓存和守护进程之间的配合构成松散耦合关系,由ALE_Reporter模块完成EPCglobal的ALE标准规划的数据处理逻辑.这种软件架构方法可以缩短开发周期,使各模块基本保持原有面貌,利于将来对软件系统进行维护和扩展.     

Hierarchical message bus-based software architectural style

As the size and complexity of software systems increase, the design and specification of overall system structure become more significant issues than the choice of algorithms and data structures of computation. An appropriate architecture for a system is a key element of its success. Based on the practice of Jadebird software production line, this paper proposes a software architectural style based on hierarchical message buses, named JB/HMB. In this style, the component model consists of external interfaces, static structure and dynamic behavior, which depicts a component from different aspects. Supported by message buses, components interact with one another by messages, which can be used to describe distributed and concurrent systems well. JB/HMB style supports stepwise decomposition and refinement, and runtime system evolution. Finally, characteristics of JB/HMB style are summarized as a conclusion, and future research directions are specified.     

体系结构动态演化中的构件行为分析

在体系结构演化的过程中,关闭运行时系统升级的代价增高和频繁改变的业务需求使得研究者考虑动态的软件升级机制.但在体系结构的动态升级过程中,由于构件风格、功能及交互方式等方面的差别,强制的构件升级会影响系统的稳定性和正确性。从构件行为的角度考虑,采用基于Wright的软件体系结构描述语言和通信顺序进程中对于进程的描述方法,描述构件行为并在构件替换之前分析原构件和新构件间的行为特性,在演化前确认构件的行为一致性,从而保证动态升级过程的正确性和合法性,以及提高系统演化的自适应性。     

软件体系结构的描述方法研究

目前关于软件体系结构的描述已有许多工具支持,但各种工具不仅是领域相关的,而且描述方法也不尽统一,这使设计人员很难选择一种合适的工具,将体系结构的共同特征提取出来,秦为体系结构描述的核心模型,为各种工具提供了共同的基础－若要用某一种工具描述,只需增加与之相关的约束,另一方面将软件体系结构与当前主流的面向对象方法相结合,利用统一建模语言ＵＭＬ的扩充机制,从多个视图描述了软件体系结构,最后结合研究工作给