共查询到20条相似文献,搜索用时 78 毫秒
1.
网构软件体系结构代数模型 总被引:1,自引:0,他引:1
由于网络化软件的规模和复杂程度的不断增加,设计可伸缩的软件体系结构,开发可演化的软件系统遇到了挑战.挑战之一是很难把软件模型与原系统说明区分开来,使得软件系统的可演化性受到限制.一个有效的途径是建立可范用软件体系结构的抽象模型,指导网构软件设计,从而提高软件模型的概括能力和可伸缩能力.本文提出一种网构软件体系结构代数模型,其中一个创新思想是把网构连接子解释成网构变量的运算.结合代数学方法和软件实现技术,定义了6种网构连接运算,所有运算是对连接子的代数抽象,因此软件体系结构的抽象表达能力得到了加强.为了展示提出代数模型的建模与分析辅助作用,介绍了一个基于代数模型的网构软件设计与演化的案例研究. 相似文献
2.
3.
4.
安全体系结构集成了软件体系结构与信息安全两大领域的研究,基于进程代数的语言适合描述基于并发交互构件的软件体系结构的一系列重要性质。使用基于进程代数的描述语言对结构中各组成元素和整体拓扑构形分别建模,形成安全的软件体系结构。 相似文献
5.
进程代数可有效地用于Web服务组合的描述和验证,然而缺乏对服务组合成本建模和分析的能力.提出一种扩展了价格信息的进程代数PPA, 在CCS基础上为进程动作和状态扩展价格函数, 给进程动作的执行标记价格,给进程的迁移状态标记成本.给出了PPA的语法和语义,定义了PPA成本弱互模拟并分析了其与CCS弱互模拟的关系,证明了PPA在CCS基础上扩展了成本建模能力,给出了成本状态空间构造算法,该算法支持选择成本优化的组合服务.实验分析了PPA用于Web服务组合成本建模和分析的可行性. 相似文献
6.
需求规约到软件体系结构(SA)模型的转换是软件工程领域的一个研究热点,UML-RT广泛用于实时系统软件体系结构建模,然而基于自然语言规约建立的UML-RT模型往往是不精确的,存在二义性,为了解决这一问题,需要赋予UML-RT模型形式化语义.进程代数是一种用来解决并发系统通信问题的形式化方法,具有精确的语法和语义,并且便于机器自动检验与验证.TCSP是进程代数CSP的实时扩展,适合于规约实时系统带有时间约束的行为.提出一种基于进程代数规约生成SA模型的方法.首先建立了自然语言规约到SA模型的转换框架;然后使用时间通信顺序进程(TCSP)描述实时系统需求规约,通过建立TCSP到UML-RT的转换机制,从而实现进程代数规约到SA模型的转换;最后通过一个实例来验证该方法在实时软件建模过程中的有效性.实验分析表明通过该方法建立的UML-RT模型能够从整体上提高实时系统SA设计的可信性. 相似文献
7.
8.
面向服务软件体系结构的XML描述和构造 总被引:2,自引:0,他引:2
介绍一种新的基于XML的用来描述服务软件体系结构的体系结构描述语言S-XADL.S-XADL规约采用XML作为元语言,集成了相关的UML 2.0 Profile规则、OCL语言和MSC表示法,除具备描述软件系统高层结构的能力,还为定义服务的交互集成模式和把服务映射到目标构件配置提供了建模元素.提出一个三阶段的软件体系结构迭代改进过程,该过程把服务视为首要的类建模元素,并认为服务是横切体系结构的方面.给出一个使用MVC模式的运行实例的面向服务体系结构建模,用以展示该方法的可行性和有效性. 相似文献
9.
一种基于进程代数的软件体系结构描述语言PEADL 总被引:1,自引:0,他引:1
对性能评价进程代数(PEPA)扩展,提出具有时序特征的随机进程代数(ESPA)。在此基础上进一步提出一种软件体系结构描述语言(PEADL)。介绍PEADL的语法和语义,并通过三层C/S结构应用系统展示PEADL的表述能力。 相似文献
10.
现有的服务组合描述途径不能有效地验证和测试组合正确性,针对这一问题,提出了一个代数规约方法,引入规约包机制扩展面向服务代数规约语言SOFIA以支持该方法。用代数规约单元描述服务系统中的各种实体,其中基调部分定义实体的语法和结构,公理部分定义其功能和行为特性。与一个服务相关的规约单元封装在一个包中或拆分在几个相互引用的包中,每个包形成一个命名空间。当多个服务组合在一起时,以这些服务的代数规约包为基础,一方面抽象地定义组合服务的交互过程和语义,形成描述服务组合实现方式的实现规约包;另一方面抽象地定义组合服务对外接口及其功能语义,形成描述组合服务需求的抽象规约包。在实现规约和抽象规约的双元结构基础上,进一步定义了实现规约和抽象规约之间必须满足的“实现”关系,证明了满足实现关系可以保证实现的正确性,从而为服务组合的可验证性和可测试性奠定了理论基础。最后结合实例分析阐述了用代数规约描述服务组合的抽象性、可表达性和可验证性。 相似文献
11.
传统构架下的ERP软件,在实际应用中出现了许多问题.文章介绍了一种新的软件架构方法--面向服务架构(SOA)的理念及其特点,并对面向服务架构的ERP和面向对象架构的ERP分别在体系结构和开发方法上作比较,最后选取SAP公司的NetWeaver和ESA产品设计理念作为案例,进一步阐述了SOA思想在ERP设计中的应用特点和优势. 相似文献
13.
14.
Performance Aware Service Pool in Dependable Service Oriented Architecture 总被引:3,自引:1,他引:3 下载免费PDF全文
As a popular approach to dependable service oriented architecture (SOA), a service pool collects a set of services that provide the same functionality by different service providers for achieving desired reliability. However, if the tradeoff between reliability and other important qualities, e.g., performance, has to be considered, the construction and management of a service pool become much more complex. In this paper, an automated approach to this problem is presented. Based on the investigation of service pools in the typical triangle SOA model, two challenges critical to the effectiveness and efficiency of service pools are identified, including which services should be held by a pool and what order these services are invoked in. A set of algorithms are designed to address the two challenges and then a service pool can be automatically constructed and managed for given reliability and performance requirements in polynomial time. The approach is demonstrated on a J2EE based service platform and the comparison results between different pooling algorithms are evaluated. 相似文献
15.
Tapio Saarelainen 《通讯和计算机》2014,(2):124-132
The pace of war is increasing since militaries are adopting the ideas of NCW (network centric warfare). Therefore, the process of war has to be modeled into the BP (business process) in order to benefit from available resources in real-time. There is an increasing need to automate command and control tools utilized in military operations because of the versatility and increase d tempo of operations. Operations can be commanded and orchestrated with the assistance of SOA (service oriented architecture). SOA is currently seen as a technology that can satisfy these needs of NCO (network centric operations). The BPs are chains of logic that request SOA services. This paper argues that in the case of a military setting, in order to achieve maximum impact with minimal effort (cf. downsizing), military operations need to be modeled as BPs (e.g., a dismounted company attack). This asks for using a RM (resource manager), a scheduler and a BSS (battle secure scheduler) in allocating the requested services (e.g., processing a fire support order). In the future, a single FFW (future force warrior), an essential performer in military operations, can benefit from the BPs approach via enhanced performance, improved SA (situational awareness) and with decreased instances of fratricide. This introduced model examines war as a business process with the assistance of SOA and discusses how a business process--like orchestration of systems and services can improve the overall performance in given military settings. 相似文献
16.
在基于分布式应用的互联网技术高速发展的今天,为解决异构平台互联、不同协议系统之间的通信、遗留系统和新增系统接口等等传统技术较难解决的问题,一种被称为"面向服务的体系架构SOA"的软件工程方法应运而生。SOA由于具有基于标准、松散耦合、共享服务、粗粒度和联合控制等优势,比以前的面向过程、面向对象、面向构件的方法能够更好地解决前述问题而日益受到软件理论界和业界的青睐。该文从概念介绍开始,逐步深入探讨SOA作为一种新型软件架构的基本特征和优点,详细介绍了SOA参考架构中的三个角色和三种操作,以及组成SOA的四个关键元素;然后把SOA与传统的软件架构进行比较,说明了SOA的必然性。 相似文献
17.
18.
随着大规模软件的出现,软件质量成为软件行业倍受关注的重点问题之一。在基于一种粗粒度松耦合的面向服务体系结构,构建了一个主动过程引擎系统模型。该模型既可以完成软件开发过程的定义、解析和组装,也提供软件过程的主动执行和行为监控,同时也支持软件过程的演化,从项目的整体过程保证软件开发任务的顺利完成和软件产品质量。 相似文献
19.
20.
Valeria Cardellini Valerio Di Valerio Vincenzo Grassi Stefano Iannucci Francesco Lo Presti 《International Journal of Software and Informatics》2013,7(2):195-220
Service selection has been widely investigated by the SOA research community as an effective adaptation mechanism that allows a service broker, offering a composite service, to bind at runtime each task of the composite service to a corresponding concrete implementation, selecting it from a set of candidates which differ from one another in terms
of QoS parameters. In this paper we present a load-aware per-request approach to service selection which aims to combine the relative benefits of the well known per-request and perflow approaches. Our service selection policy represents the core methodology of the Plan phase of a self-adaptive service oriented system based on the MAPE-K reference loop. Since the service broker operates in a variable and uncertain environment where the QoS levels negotiated with the service providers can fluctuate, it requires some mechanism to enforce the QoS constraints with its users. To this end, we also propose an algorithm for the Analyze phase of MAPE-K which is based on the adaptive Cusum algorithm and allows to determine whether a change in the QoS level requires a service selection replanning. We
present experimental results obtained with a prototype implementation of a service broker. Our results show that the proposed load-aware approach is superior to the traditional perrequest one and combines the ability of sustaining large volume of service requests, as the perflow approach, while at the same time offering a finer customizable service selection, as the per-request approach. Furthermore, the results show that the adaptive Cusum algorithm
can quickly detect changes in the execution environment and trigger a new optimization plan
before the system performance degrades. 相似文献