Web服务复合技术在SOA系统中的研究与应用

随着以Web服务为基础的面向服务的体系结构的发展,如何复合分布的、自治的Web服务以构建新的企业业务应用的问题已成为软件工程领域一个新的热点问题。本文研究探讨了Web服务复合技术在面向服务体系的系统开发中的应用,并在此基础上提出一个基于Web服务复合技术的应用程序设计模式。     

Web服务复合技术在SOA系统中的研究与应用

随着以Web服务为基础的面向服务的体系结构的发展，如何复合分布的、自治的Web服务以构建新的企业业务应用的问题已成为软件工程领域一个新的热点问题。本文研究探讨了Web服务复合技术在面向服务体系的系统开发中的应用，并在此基础上提出一个基于Web服务复合技术的应用程序设计模式。     

Eine Dienstgüte unterstützende Webservice-Architektur für flexible Geschäftsprozesse

Web services as a technology to enable distributed business processes gain in importance. However, the support of Quality of Service (QoS) is crucial in this context. Thus, we present an integrated web service architecture with comprehensive QoS support. The architecture we introduce in this paper supports the assessment of web services to assure that only web services will be used in critical business processes that satisfy the requirements defined by the user. The selection and execution of a certain web service depends on its QoS-properties that must be guaranteed in Service Level Agreements (SLAs). The compliance with SLAs is monitored by the system as well. Furthermore we introduce a prototypical implementation of our web service architecture.     

面向SOA架构的单通道应用程序模式的改进

随着以Web服务为基础的面向服务的体系结构的发展，如何复合分布的、自治的Web服务以构建新的企业业务应用问题已成为软件工程领域一个新的热点问题。研究探讨一种面向SOA架构的单通道应用程序设计模式，并通过Web服务复合技术对这种程序模式进行改进，通过项目应用验证其可行性。     

PDC-Agent支持的动态自组织系统

提出一种基于政策（P）、愿望（D）和合同（C）的扩展Agent模型（PDC-Agent），并以它为基础，建立用于网络服务自动合成的方法体系．PDC-Agent根据3个因素（P，D和C），运用基于优先级的决策机制，理性地选择将要执行的服务和特性。并参与虚拟组织的建立和服务的合成．最后给出服务自组织的过程和实例分析．该系统能够适应商业需求的变化，在开放、动态、异构的虚拟组织环境中进行即时的服务集成．     

End-to-end reliability of service oriented applications

As organizations move towards adopting a service oriented architecture that permits the coexistence of multiple technology environments, an increasing number of applications will be developed through the assembly of existing software components with standard web service interfaces. These components with web service interfaces may be available in-house, or may be supplied or hosted by external vendors. The use of multiple services, possibly utilizing different technologies, providers, locations, and sources, has implications for the end-to-end reliability of these applications to support a business process. Selecting the best service for individual tasks in a business process does not guarantee the most effective overall solution, particularly if criteria other than functional characteristics are employed. This paper examines reliability issues associated with applications developed within service oriented architecture. It develops a measure for deriving end-to-end application reliability, and develops a model to help select appropriate services for tasks in the business process which accommodate the redundant and overlapping functionality of available services and planned redundancy in task support to satisfy the reliability requirement of the resulting application. A genetic algorithm approach is adopted to select promising services to assemble the application using end-to-end reliability as the criterion of interest. An application to a real-world business process illustrates the effectiveness of the approach.     

PBA4WSSP: a policy-based architecture for web services security processing

Due to the dynamic, heterogeneous and interorganizational nature, different web services and different ports or operations in the same service, even the same services at different times may have their different security requirements because of their different security domains and different business backgrounds. How to design a flexible, fine-grained and comprehensive architecture for web services security processing has become a matter of great urgency. However, no ideal solutions have been worked out for these problems. As a result of our study, we have presented in this paper a policy-based architecture termed policy-based architecture for web services security processing (PBA4WSSP) to meet the dynamic, complete and fine-grained security requirements. In PBA4WSSP, the processing of all security problems is based on security policy in service stage to support flexibly security configuration. Moreover, we have designed a service policy model to describe the fine-grained security requirements. And the conversion method between security policy model and security policy expression has also been described. In addition, a staged complete security processing architecture is provided to reduce the dependency among protocol implementations. Furthermore, with PBA4WSSP, a web service security module has been designed and implemented as well. Eventually, the performance evaluation results amply demonstrate that our system is flexible and usable.     

Web Service Diagnoser Model for managing faults in web services

Reliability is an important criterion to facilitate extensive deployment of web service technology for commercial business applications. Run-time monitoring and fault management of web services are essential to ensure uninterrupted and continuous availability of web services. This paper presents WISDOM (Web Service Diagnoser Model) a generic architecture for detecting faults during execution of web services. Policies have been proposed to describe the intended behavior of web services and faulty behavior would be detected as deviations or inconsistencies with respect to the specified behavior. The model proposes the use of monitoring components in service registries and service providers to detect run-time faults during publishing, discovery, binding and execution of web services. An independent fault diagnoser is proposed to coordinate the individual monitoring components and also act as a repository for the specified web service policies. The proposed model has been tested with a sample web service application and the results obtained are presented.     

On the verification of security-aware E-services

Web services providing E-commerce capabilities to support business transactions over the Internet are more and more widespread. The development of such services involves several security issues ranging from authentication to the management of the access to shared resources according to a given business model. The capability of validating designs against fast evolving requirements is of paramount importance for the adaptation of business models to changing regulations and rapidly evolving market needs. So, techniques for the specification and automated analysis of web services to be used in security-sensitive applications are crucial in the development of these systems.     

Synthy: A system for end to end composition of web services

The demand for quickly delivering new applications is increasingly becoming a business imperative today. However, application development is often done in an ad hoc manner resulting in poor reuse of software assets and longer time-to-delivery. Web services have received much interest due to their potential in facilitating seamless business-to-business or enterprise application integration. A web service composition system can help automate the process, from specifying business process functionalities, to developing executable workflows that capture non-functional (e.g. Quality of Service (QoS)) requirements, to deploying them on a runtime infrastructure. Intuitively, web services can be viewed as software components and the process of web service composition similar to software synthesis. In addition, service composition needs to address the build-time and runtime issues of the integrated application, thereby making it a more challenging and practical problem than software synthesis. However, current solutions based on business web services (using WSDL, BPEL, SOAP, etc.) or semantic web services (using ontologies, goal-directed reasoning, etc.) are both piecemeal and insufficient. We formulate the web service composition problem and describe the first integrated system for composing web services end to end, i.e., from specification to deployment. The proposed solution is based on a novel two-staged composition approach that addresses the information modeling aspects of web services, provides support for contextual information while composing services, employs efficient decoupling of functional and non-functional requirements, and leads to improved scalability and failure handling. We also present Synthy, a prototype of the service composition system, and demonstrate its effectiveness with the help of an application scenario from the telecom domain.     

A tentative commit protocol for composite web services

Composite web services provide promising prospects for conducting cross-organizational business transactions. Such transactions: are generally complex, require longer processing time, and manipulate financially critical data. It is therefore crucial to ensure stronger reliability, higher throughput and enhanced performance of transactions. In order to meet these requirements, this paper proposes a new commit protocol for managing transactions in composite web services. Specifically, it aims to improve the performance by reducing network delays and the processing time of transactions. The proposed protocol is based on the concept of tentative commit that allows transactions to tentatively commit on the shared data of web services. The tentative commit protocol avoids resource blocking thus improving performance. The proposed protocol is tested through various simulation experiments. The outcomes of these experiments show that the proposed protocol outperforms existing protocols in terms of transaction performance.     

Adaptive integration activity management for on demand business process collaboration

Today businesses are interacting and collaborating more often in the context of a business value chain involving a variety of partners to deliver products and services. Business to business (B2B) connectivity, Enterprise Application Integration (EAI) and general business collaboration processes are becoming more critical in operating and managing efficient enterprises. The required level of inter and intra enterprise integration is generally a large undertaking and involves substantial development and customization efforts. In this paper, we propose an adaptive integration activity management approach based on web services technologies to reduce code changes associated with business process integration in a distributed collaboration environment. Specifically, we present a concept of activity chain to capture non-deterministic process flows as well as deterministic process flows in a uniform manner. Then an Activity Ontology is introduced to capture the integration requirements that include adaptation behaviors, action properties, business rules, and access control policy references. The unique ontology representation and management of the integration activities provides a uniform way to integrate additional internal and external business applications to reduce the need for pre-defined and hard-wired integration methods and to minimize code changes to existing components in an existing business collaboration and integration (B2B/EAI) infrastructure. In addition, a Petri-Net modeling exercise of the proposed integration activity management is performed to help better understand the actual system and improve the system design beforehand.     

SOA的架构功能需求分析

面向服务的架构（SOA）作为一种架构方法,将企业应用中分散的功能组织成为基于标准、松耦合、可互操作的业务服务。SOA让IT变得更有弹性,能够更快地响应业务需求,从而实现更好的业务灵活性。本文对SOA架构的优势进行了简要分析,同时对其功能需求也提出了4个基本要求。     

基于Web服务的B2E移动电子商务平台的设计与实现

随着电子商务技术的逐渐成熟,实施移动化成为企业考虑的重点和未来发展的趋势.在移动商务中使用Web服务,是目前较新较可行的方式,提出了一个.NET环境下的基于Web服务的B2E(企业对员工)移动商务平台的设计架构,此平台功能包括任务管理、个人事务管理、客户资料管理、订单查询等功能,采用三层结构进行设计,用户可以使用手机、PDA或桌上型浏览器,使用本平台提供的服务,以达到移动商务的目的.     

网格服务的合成模型研究

开放网格体系结构OGSA规范通过整合网格和Web服务技术确定了网格服务分布式系统框架，但其中关于网格服务合成的方面并没有定义相应的规范，业务流程执行语言BPEL4WS是应用于Web服务上的服务合成规范。通过分析网格服务和Web服务的异同，设计出一种可行的模型，解决了BPEL4WS不支持网格服务中部分特性的问题，从而可以将BPEL4WS应用于网格服务合成上。     

基于Web Service的家庭人体健康监护系统快速开发平台

家庭人体健康监护系统作为上下文感知应用的一种,越来越多的被应用到有老人或病人的家庭中。该文提出一种新的面向服务的开发平台,引入Web Service框架,将家庭人体健康监护系统中的软硬件集成模块抽象成独立的网络服务,开发人员既可以直接调用这些服务,又可以创建基于这些服务的业务流程,极大的提高了工作效率。     

一个Web服务管理框架设计方案

简单地说,Web服务(Web Services)就是自描述模块化的业务应用程序,它可以通过可编程接口经由Internet将业务逻辑发布为服务,并通过XML,SOAP,WSDL,UDDI和ebXML等标准协议来查找、订阅和调用这些服务。文中针对日益增长的Web服务管理的需求以及存在的问题,对Web服务管理(Web Service Management)、Web服务管理原则和管理模式等做了深入的研究探讨,提出了一个Web服务管理框架设计方案,同时阐明了框架的内部组成模块以及各部分之间的相互关系。     

基于Web Services架构的制造业信息化模型研究

针对目前制造业信息化系统存在的不足，提出一种基于Web Services架构的制造业信息化模型建立方法，即对Web Services架构及其支撑技术、工作模式进行详细的研究后。按照产品生命周期建立制造业信息化模型，给出模型组成结构和功能设计，论述了模型实现的模式，从而实现制造业电子化的B2B(business to business)和B2C(business to customer)业务．