软件技术的新热点面向服务的计算

1、为研究生做的讲座 2005.11,1,软件技术的 新热点： 面向服务的计算 Service-Oriented Computing (SOC),西北大学软件工程研究所 郝克刚,2,为研究生做的讲座 2005.11,Service-Oriented Computing (SOC) 讲座大纲,软件技术的新热点：面向服务的计算。 发展的历史渊源：从 结构化设计、 面向对象、面向构件 到面向服务。 面向服务的结构 SOA 。 服务的描述。 服务的发现。 服务的组合。 模型和理论。 结束语。,3,为研究生做的讲座 2005.11,一，软件技术的新热点,面向服务的计算Service-Oriented Com

2、puting(SOC)， 面向服务的结构Service-Oriented Architecture (SOA).,4,为研究生做的讲座 2005.11,Bill Gates : Microsoft .NET Today June 14, 2001,Much of the information your business needs is locked up in centralized databases, served up a page at a time to individual users. Worse, Web pages are simply a “picture” of th

3、e data, not the data itself, forcing many developers back to “screen scraping” to acquire information. todays standalone applications and Web sites create islands of functionality and data. Solving such problems is the key challenge for the next generation of the Internet. At the heart of the soluti

4、on is eXtensible Markup Language, or XML. With the help of XML-based technologies such as SOAP and UDDI, they are creating a new type of software,5,为研究生做的讲座 2005.11,各软件公司纷纷提出对策。 Microsoft 比尔盖茨关于消除信息孤岛的讲话。 Sun. 面向服务的体系结构因其固有的松散耦合与互操作性，成为许多企业应用的自然选择。使用 J2EE 提供的 Web 服务功能可以很容易地构建能够访问现有业务流程的 SOA 系统。 IBM推

5、新软件与服务 隶属面向服务体系结构。 Oracle。应用程序网格计算的特征和优点恰恰是面向服务体系结构(SOA) 的特征和优点。,6,为研究生做的讲座 2005.11,World Wide Web Consortium (W3C),an international consortium where Member organizations, a full-time staff, and the public work together to develop Web standards 成立工作组， Web Services Addressing Working Group , Web Serv

6、ices Description Working Group Web Services Architecture Working Group Semantic Web Services Interest Group Web Services Choreography Working Group 制定标准： XML-RPC, SOAP, UDDI “yellow pages” that categorize businesses by standard taxonomies; “green pages” that document the technical information about

7、services that are exposed.,61,为研究生做的讲座 2005.11,Yellow, Green, and White Pages in UDDI,62,为研究生做的讲座 2005.11,WSDL UDDI Correspondence,63,为研究生做的讲座 2005.11,如何从已有的Web服务经过组合，构造新的Web服务，已成为关注的一个焦点。为了得到可靠的，高质量的服务，必须找到一种建模方法、语言和工具，进行服务的组合，以及分析和验证。,六，服务的组合 Service Composition,64,为研究生做的讲座 2005.11,Service Composi

8、tion,Industry Solution: WSDL +BPEL4WS BPEL4WS proposed by IBM and Microsoft), which specifies the roles of each of the partners and the logical flow of the message exchanges BPEL4WS provides programming-language like constructs (sequence, switch, while, pick) as well as graph-based links that repres

9、ent additional ordering constraints on the constructs.,65,为研究生做的讲座 2005.11,Service Composition,WS-BPEL Business Process Execution Language for Web Services version 1.1 Contributors: IBM, BEA Systems, Microsoft, SAP AG, Siebel Systems 30 Jul 2002Updated 01 Feb 2005 Semantic Web Solution: RDF/DAML-S +

10、 Golog/Planning,66,为研究生做的讲座 2005.11,Web Service Composition - Current Solutions and Open Problems,none of the approaches has developed a true planning solution to the service composition problem so far. Plans need to contain complex control structures involving loops, nondeterminism, and choice. The

11、 planning problem cannot really be expected to take place at the level of primitive actions and control structures, but seems to require to take complex plans as building blocks and synthesize multipartner interactions from them. web services create new objects at runtime, i.e., they produce message

12、 objects during their execution that then can be further processed by other services.,67,为研究生做的讲座 2005.11,Standards for Web Services,68,为研究生做的讲座 2005.11,W3C Candidate Recommendation 9 November 2005,Web Services Choreography Description Language Version 1.0 Choreography 辞典：安排被比作舞蹈编排的某样东西，如一种情况或一系列情况或

13、者是一系列计划等： Web 服务编排描述语言,69,为研究生做的讲座 2005.11,Web Services Choreography Description Language,WS-CDL is an XML-based language that describes peer-to-peer collaborations of participants describes collaborations of participants by defining from a global viewpoint their common and complementary observable

14、behavior, where information exchanges occur, when the jointly agreed ordering rules are satisfied,70,为研究生做的讲座 2005.11,七，模型和理论。,计算机科学理论和形式化方法对软件技术的重要作用。 计算机的诞生和图灵机器。 高级语言和编译系统和形式语言自动机理论。 数据库及有关关系代数理论。 高可信软件同程序的正确性证明，形式语义和时态逻辑学。,71,为研究生做的讲座 2005.11,Petri Net 佩特里网,Petri 网是德国学者Carl Adam Petri教授于1962年在其博

15、士论文“自动机通信”中提出的一种网络图理论。70年代以后，Petri 网理论引起人们的重视，得到迅速发展并应用于解决计算机科学领域的问题。 Petri 网既有严格的数学定义，又有直观的图形表示，特别适合描述离散事件系统的控制流、并发特性和异步行为。,72,为研究生做的讲座 2005.11,Petri Net 是一种很好的模型,非结构化，并行，竞争，同步，,73,为研究生做的讲座 2005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,74,为研究生做的讲座 2005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,75,为研究生做的讲座 2

16、005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,76,为研究生做的讲座 2005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,77,为研究生做的讲座 2005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,78,为研究生做的讲座 2005.11,非结构化，并行，竞争，同步，,Petri Net 是一种很好的模型,79,为研究生做的讲座 2005.11,软件工程研究所在Petri 网方面的工作,郝克刚: “Petri 网与结构的 Petri 网”，微电子学与计算机，1985年 第6期。 郝克刚，段振华：“

17、多出口 Petri 网与 Petri 网的等价性”， 计算机学报， 郝克刚，张 慧，侯 红：“Petri 网工具(GPNT)的设计与实现”， 软件学报， 1991年 第3期。 郝克刚,葛玮：“关于高级网系统的等价及谱系的研究”，计算机学报，1993 年第7期， 郝克刚：开放网-交互式并行系统的模型，西北大学学报（自然科学版），1997, 5。,80,为研究生做的讲座 2005.11,软件工程研究所在Petri 网方面的工作,岳晓丽,杨 斌,郝克刚.信牌驱动式工作流计算模型. 计算机研究与发展, 2000,(37) 12 郝克刚，王斌君。.非确定Petri网。小型微型计算机系统（2003。3（2

18、4）。 郝克刚，王斌君。 扩展的信牌驱动模型与Petri网。 计算机应用与软件（2004.2(21) ）。 郝克刚，王斌君，安 贵。 WPDL中的JOIN语义问题和分区解决方案。计算机科学（2003。7（30）。 Kegang Hao：Two Formal Models of Interactive Machine ,Proceedings of The Third Asian Workshop on Foundations of Software, Xian, China, November, 2004；,81,为研究生做的讲座 2005.11,罗宾. 米尔纳 的演算,The -calcul

19、us是 Robin Milner在下述演算系统的基础上建立的。 Churchs -calculus equivalent to Turing Machines his earlier CCS (calculus for communicating systems) Anthony Hoare process algebra CSP (communicating sequential processes).,82,为研究生做的讲座 2005.11,The Monadic -calculus Basic ideas,The most primitive entity in -calculus is

20、 a name. Names, infinitely many, are x,y, X there is only one other kind of entity: a process. Processes are P,Q, P and are built from names by this syntax P := iIi Pi | P | Q | !P | (x)P,83,为研究生做的讲座 2005.11,P := iIi Pi | P | Q | !P | (x)P,Here I is a finite indexing set. in the case I = we write th

21、e sum as 0. In a summand P the prefix represents an atomic action, the first action performed by P . There are two basic forms of prefix : x(y), which binds y in the prefixed process, means “input some name ( call it y ) along the link named x” , which does not bind y, means “output the name y along

22、 the link named x ”,84,为研究生做的讲座 2005.11,P := iIi Pi | P | Q | !P | (x)P,The summation form iIi Pi represents a process able to take part in one, but only one, of several alternatives for communication. Processes in this form are called normal processes (because as we see later, all processes can be

23、converted to this normal form) For normal processes M,N, N we shall use the following syntax: N := P | 0 | M + N,85,为研究生做的讲座 2005.11,P := iIi Pi | P | Q | !P | (x)P,P |Q simply means that P and Q are concurrently active so they can act independently but can also communicate !P means P |P | as many c

24、opies as you wish There is no risk of infinite concurrent activity, our reduction rules will see to that. The operator “!” is called replication. A common instance of replication is !P ,a resource which can only be replicated when a requester communicates via ,86,为研究生做的讲座 2005.11,P := iIi Pi | P | Q

25、 | !P | (x)P,Finally, (x)P, new x in P restricts the use of the name x to P. Another way of describing it is that it declares a new unique name x distinct from all external names for use in P,87,为研究生做的讲座 2005.11,Some simple examples,reduction,88,为研究生做的讲座 2005.11,SOC 涉及的研究方向 （上）,Service Description S

26、ervice Discovery Service Composition Service Monitoring Service Deployment Service Middleware Service Oriented Architectures Service Development and Maintenance Programming models for Service Oriented Applications,89,为研究生做的讲座 2005.11,SOC 涉及的研究方向 （中）,Methodologies for Service Oriented Applications Novel business models for service-oriented applications Economical implications of Web services and SOAs Formal Methods for Service Oriented Architectures Service Testing and Validation Service Lifecycle Managemen