Web服务测试技术综述

面向服务的体系结构（SOA）已成为基于Web的分布式系统的主要发展趋势。Web服务作为实现SOA的一种形式,已得到广泛的关注与应用。由于Web服务为基于开放和通用的协议与平台,其服务质量与可信等均可能存在问题,这将会阻碍Web服务的发展。Web服务进行充分测试可保证Web服务的质量,然而由于Web服务所具有的特点,传统的软件测试技术方法不再适用于Web服务的测试,所以对Web服务测试方法和技术的研究成为当务之急。本文在SOA体系结构基础上,讨论了Web服务测试的难点和Web服务测试的基本方法,分析了目前Web服务测试的研究现状。最后,展望了未来可能的研究方向。     

Building Web services middleware with predictable execution times

Predictability of execution has seldom been considered important in the design of Web services middleware. However, with the paradigm shift brought by cloud computing and with offerings of Platforms and Infrastructure as services, execution level predictability is mandating an increased importance. Existing Web services middleware are optimised for throughput with unconditional acceptance of requests and execution in a best-effort manner. While achieving perceived levels of throughput, they also result in highly unpredictable execution times. This paper presents a generic set of guidelines, algorithms and software engineering techniques that enable service execution to complete within a given deadline. The proposed algorithms accept requests for execution based on their laxity and executes them to meet requested deadlines. An introduced admission control mechanism results in a large range of laxities, enabling more requests to be scheduled together by phasing out their execution. Specialised development libraries and operating systems empower them with increased control over execution. Two widely used Web services middleware products were enhanced using these techniques. The two systems are compared with their unmodified versions to measure the predictability gain achieved. Empirical evidence confirms that the enhancements made enable these systems to achieve more than 90% of the deadlines under any type of traffic, while the unmodified versions achieve less than 10% of the deadlines in high traffic conditions. Predictability of execution achieved through these techniques, would open up new application areas such as industrial control systems, avionics, robotics and financial trading systems to the use of Web services as a middleware platform.     

Web应用测试技术进展

Web应用的特殊性使得其测试具有挑战性,但目前针对其测试的研究同其设计开发的研究相比相对薄弱.从Web应用的体系结构、实现技术、组成成分、运行机制、运行环境、开发设计等方面分析了影响测试的因素.归纳了现有Web应用设计阶段、开发阶段、运行阶段、维护阶段所涉及的主要测试方面及使用的动态、静态测试技术.并从测试的几个关键方面,如链接测试、组件黑盒测试、组件白盒测试、WS及WSC测试及性能测试等方面综述当前研究热点难点,包括面向对象的建模、统计建模、控制流测试、数据流测试、数据组合测试、WS测试、WS组测试、WSC测试、协议测试、性能测试的负载模型与用户会话数据集的优化等问题.指出了有关研究的局限性.从模型驱动测试、基于Agent测试、WS及SOA测试、性能测试等方面探讨了Web应用测试未来的研究方向.     

A systematic review of tools,languages, and methodologies for mashup development

Web 2.0 has become a powerful means of transmitting information in a number of fields, such as communication, e‐commerce, and entertainment. Nowadays, companies and organizations transmit specific information through different mechanisms, such as Web feeds and Web services. These data sources enable third parties to incorporate data from service providers into their own applications. On the basis of this understanding, mashups have emerged as a new approach to develop applications and which combine data and resources from heterogeneous sources—such as internal data sources, Web feeds, screen scraping, and Web services—with the aim of solving specific needs. Mashup development involves activities such as accessing heterogeneous sources, combining data from different data sources, and building graphical interfaces. These activities restrict the development of these kinds of applications only to experienced computer users. Today, a number of tools and programming languages are used to help carry out some of the aforementioned activities. These tools and programming languages have features enabling the integration of different technologies in order to solve problems such as data management from different data sources and content publication. If this is taken into account, there is a growing need to learn about the features, advantages, and disadvantages of these tools and programming languages in order to select the tool or language that best fits a specific need and a specific level of knowledge and experience in terms of software development. This paper presents a systematic review and analysis of the tools, programming languages, and software development methodologies involved in mashup development in order to learn more about the features and services provided by mashups. Furthermore, this research also explains the qualitative and quantitative evaluation used for the mashup development tools. The evaluation was performed in order to measure not only the usability of these tools but also the support that they provide for standardized features of Web development that they provide. Finally, new trends in the development of mashups are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Web服务测试研究

Web服务技术为软件测试研究带来了新的挑战。Web服务测试需要能够适应面向服务的新的分布式计算体系架构。为保证服务的质量，Web服务需要从多个层次进行验证与确认，包括基础设施、单元服务、集成服务等；测试需涵盖服务的功能、性能、可靠性、安全等各个方面。本文从web服务体系架构和应用模式出发，讨论了Web服务测试的主要问题。文章分析当前相关研究的现状，并归纳总结了SOAP协议验证、WSDL语言扩展、基于模型的服务集成验证、和测试构架等主要研究成果。本文最后讨论了当前存在的主要问题及进一步的研究方向。     

用分类树方法实现Web服务测试例的自动生成

随着Web服务技术的不断发展和广泛应用,需要运用新的测试技术来保障Web服务的正确有效运行,而测试例的生成是Web服务测试的一项重要内容,它将直接关系到Web服务测试的效率和成本。基于Web服务的WSDL文档,根据输入域中子集间相互关系,利用分类树的方法(Classification Tree Method),提出Web服务测试例的一种自动生成方法,据此达到最少的数量最大限度地进行覆盖的目的,并结合具体的实例,使用CTE测试工具增强测试的自动化程度,从而提高软件测试的效率和软件的质量。     

Learning domain ontologies for semantic Web service descriptions

High quality domain ontologies are essential for successful employment of semantic Web services. However, their acquisition is difficult and costly, thus hampering the development of this field. In this paper we report on the first stage of research that aims to develop (semi-)automatic ontology learning tools in the context of Web services that can support domain experts in the ontology building task. The goal of this first stage was to get a better understanding of the problem at hand and to determine which techniques might be feasible to use. To this end, we developed a framework for (semi-)automatic ontology learning from textual sources attached to Web services. The framework exploits the fact that these sources are expressed in a specific sublanguage, making them amenable to automatic analysis. We implement two methods in this framework, which differ in the complexity of the employed linguistic analysis. We evaluate the methods in two different domains, verifying the quality of the extracted ontologies against high quality hand-built ontologies of these domains.

Our evaluation lead to a set of valuable conclusions on which further work can be based. First, it appears that our method, while tailored for the Web services context, might be applicable across different domains. Second, we concluded that deeper linguistic analysis is likely to lead to better results. Finally, the evaluation metrics indicate that good results can be achieved using only relatively simple, off the shelf techniques. Indeed, the novelty of our work is not in the used natural language processing methods but rather in the way they are put together in a generic framework specialized for the context of Web services.     

Leveraging user-session data to support Web application testing

Web applications are vital components of the global information infrastructure, and it is important to ensure their dependability. Many techniques and tools for validating Web applications have been created, but few of these have addressed the need to test Web application functionality and none have attempted to leverage data gathered in the operation of Web applications to assist with testing. In this paper, we present several techniques for using user session data gathered as users operate Web applications to help test those applications from a functional standpoint. We report results of an experiment comparing these new techniques to existing white-box techniques for creating test cases for Web applications, assessing both the adequacy of the generated test cases and their ability to detect faults on a point-of-sale Web application. Our results show that user session data can be used to produce test suites more effective overall than those produced by the white-box techniques considered; however, the faults detected by the two classes of techniques differ, suggesting that the techniques are complementary.     

Special section on testing and security of Web systems

This special section is devoted to a selection of papers that have been originally published in the Proceedings of the International Workshop on Web Quality, Verification and Validation (WQVV) held in Como, Italy, in July 2007. The workshop was part of the Seventh International Conference on Web Engineering (ICWE 2007). These papers investigate different issues of two fundamental “aspects” of quality and dependability of modern Web systems: testing and security. The main contribution of this special section consists in trying to bring the gap between research and “industrial” practice in Web systems. The use of new technologies, tools and methodologies is increasing in the Web and it makes the systems more and more interactive and responsive than in the past. Therefore, limits and problems related to specific aspects of systems quality and dependability are investigated, and new approaches and ideas are proposed to overcome such limitations.     

Web服务的Pi演算描述

如何从已有的 Web 服务构造新的增值性的正确的 Web 服务,已成为研究 Web 服务的群体关注的一个焦点。因此,为了得到可靠的、高质量的服务,必须找到一种建模方法和工具,在 Web 服务投入使用之前,对其进行分析和验证。本文主要从过程代数的角度出发,用 Pi 演算来描述 Web 服务以及 Web 服务的组合。     

Applying model-driven engineering to the development of Rich Internet Applications for Business Intelligence

Business Intelligence (BI) applications have been gradually ported to the Web in search of a global platform for the consumption and publication of data and services. On the Internet, apart from techniques for data/knowledge management, BI Web applications need interfaces with a high level of interoperability (similar to the traditional desktop interfaces) for the visualisation of data/knowledge. In some cases, this has been provided by Rich Internet Applications (RIA). The development of these BI RIAs is a process traditionally performed manually and, given the complexity of the final application, it is a process which might be prone to errors. The application of model-driven engineering techniques can reduce the cost of development and maintenance (in terms of time and resources) of these applications, as they demonstrated by other types of Web applications. In the light of these issues, the paper introduces the S^m4RIA-B methodology, i.e., a model-driven methodology for the development of RIA as BI Web applications. In order to overcome the limitations of RIA regarding knowledge management from the Web, this paper also presents a new RIA platform for BI, called RI@BI, which extends the functionalities of traditional RIAs by means of Semantic Web technologies and B2B techniques. Finally, we evaluate the whole approach on a case study—the development of a social network site for an enterprise project manager.     

Web服务组合测试综述

随着面向服务技术和云计算技术的不断成熟,尤其是面向服务体系结构SOA的不断完善以及推广,使得其主要内容Web服务已经被广泛应用.为了充分利用Web服务并解决单个Web服务的功能有限的问题,业界将多个原子Web服务按照一定的规则和业务逻辑进行组合,以提供更多功能更强大的服务,实现了Web服务的增值和复用.为保证Web服务组合的质量,需要对Web服务组合进行全面、充分的测试.然而,由于Web服务组合的动态特性和分布式特点,使得其测试技术与方法和传统的软件测试有很大区别,存在很多挑战.本文针对Web服务组合测试,对近年来Web服务组合测试研究中的测试用例生成技术、回归测试技术、测试执行和度量方法进行了系统地总结和分析.此外,我们还对Web服务组合测试中有待研究的问题进行了分析和展望.     

Genetic programming for QoS-aware web service composition and selection

Web services, which can be described as functionality modules invoked over a network as part of a larger application are often used in software development. Instead of occasionally incorporating some of these services in an application, they can be thought of as fundamental building blocks that are combined in a process known as Web service composition. Manually creating compositions from a large number of candidate services is very time consuming, and developing techniques for achieving this objective in an automated manner becomes an active research field. One promising group of techniques encompasses evolutionary computing, which can effectively tackle the large search spaces characteristic of the composition problem. Therefore, this paper proposes the use of genetic programming for Web service composition, investigating three variations to ensure the creation of functionally correct solutions that are also optimised according to their quality of service. A variety of comparisons are carried out between these variations and two particle swarm optimisation approaches, with results showing that there is likely a trade-off between execution time and the quality of solutions when employing genetic programming and particle swarm optimisation. Even though genetic programming has a higher execution time for most datasets, the results indicate that it scales better than particle swarm optimisation.     

Web Services:分布式网络体系新架构

Web服务作为一种新型的分布式网络体系架构成为目前研究的热点。该文从分布式计算技术与Grid计算和XML等技术发展融合的角度分析了Web服务发展历程和概念定义。提出了一种RSRPM新的Web Services架构模型和形式化定义，并对实现时所需要采用的核心步骤、指令方法以及核心协议栈进行了分析和描述。另外，在对目前Web服务的应用情况进行分析的基础上，指出了Web服务存在的局限性、4个主要的技术问题以及未来的发展趋势。     

Recommending multimedia web services in a multi-device environment

In the last years, the Web community has shown a broad interest in Web services that handle multimedia contents. To improve the usability of these services different tools have been proposed in the literature, and in this context agent-based recommender systems appear to be a promising solution. However, the recommender systems presented in the past do not take into account, in their recommendation algorithms, the effect of the device exploited by the user, while it is clear that the same user shows a different behavior in the presence of different devices. This paper tries to give a contribution in this setting, in order to match more accurately user preferences and interests. In particular, a new agent-based system is proposed, whose architecture allows to compute recommendations of multimedia Web services, considering the effect of the currently exploited device. Some experimental results confirm the high quality of the recommendations generated by the proposed approach.     

A framework for XML schema naming and design rules development tools

Many organizations are facing enormous challenges today in trying to integrate a wide range of software systems. These systems span the functional areas within an organization, as well as, the multitude of organizations and countries involved in a business process. To address the needs of information integration a number of organizations are developing standards to define the information units that will be shared. Many of these standards are an application of the XML family of software standards, hence the proliferation of content standards or xML standards. To ensure quality in the emerging content standards, the organizations producing them also define guidelines for how the XML standards, especially XML Schema, will be used in a given context. These guidelines are published as sets of Naming and Design Rules (NDR). Unfortunately, a single set of these rules do not meet the needs of the wide range of standards being developed. Moreover, the guidelines are being published as prose (e.g., English text) rather than in a computational form.To address these shortcomings and allow for the more rapid creation of high quality NDR, the National Institute of Standards and Technology (NIST) is developing a set of tools to facilitate NDR development. The tools support the development of executable tests to support NDR, collaboration on the use of those tests, the grouping of tests into testing profiles, as well as, the association of NDR documentation with executable tests. The grouping mechanism allows rules to be selected from a larger set for use in a particular context. By also providing for the association of guidelines with executable tests, a testing suite can be quickly assembled. Furthermore, the pool of guidelines and their tests can be collaboratively developed, thereby leveraging resources and creating higher quality test sets in the end.The report describes a framework for tools to support the development of NDR for XML Schema. The tools aid in producing high quality XML schemas using a standards-based approach to information integration. The tools are based on open standards, making them highly configurable and reusable. The three primary functional areas of the tools described are authoring, testing, and sharing.