Web Services Specifications Research Articles

Generating test case for algebraic specification based on Tabu search and genetic algorithm

To improve the effectiveness of generating test case for algebraic specification, an approach for generating test cases based on tabu search and genetic algorithm (Tabu GA) is presented. A prototype tool CASCATT (Common Algebraic Specification-based Class, Component and Web service Automatic Testing Tool) is implemented based on Tabu GA, which tests Class, Component and Web Service based on algebraic specification described by CASOCC-WS (Common Algebraic Specification of Components, Classes and Web service) language. The experiments results show the testing method is better effective, comparing with the existed random method in algebraic testing tool CASCAT (Common AS-based Component Automatic Testing) which generated test case from random data rewriting technology.

Modeling energy-aware web services and application

Cloud computing provides an infrastructure where large organizations can redundantly distribute their software assets across geographically distributed data centers. Consequently, on the account of the importance of energy efficiency, these organizations have to strategically configure their overall operations to leverage power availability as it changes, reduce their overall energy costs, and promote energy-efficiency throughout the entire system. Traditional state-of-the-art approaches rely on the monitoring and configuration of systems based on load measurements taken directly from their hardware assets. These measurements are largely independent of the underlying software applications. In this work, we introduce a decision support procedure to provide a priori, deterministic understanding of power consumption of modular software assets or services that reside on the hardware devices/servers. The proposed decision support procedure relies on power estimation models that predict power consumption of a software service considering the type of server on which it resides. The proposed procedure also embeds a smart sampling technique that will help monitor and record the system behavior effectively for the provisioning of new software services. Experiments demonstrate favorable predictions of the power consumption of a specific web service or group of web services and the promise of more energy-efficient operations of distributed cloud environments.

Open Marketplace for Simulation Software on the Basis of a Web Platform

The focus in development of a new generation of middleware shifts from the global grid systems to building convenient and efficient web platforms for remote access to individual computing resources. Further line of their development, suggested in this work, is related not only with the quantitative increase in their number and with the expansion of scientific, engineering, and manufacturing areas in which they are used, but also with improved technology for remote deployment of application software on the resources interacting with the web platforms. Currently, the services for providers of application software in the context of scientific-oriented web platforms is not developed enough. The proposed in this work new web platforms of application software market should have all the features of the existing web platforms for submissions of jobs to remote resources plus the provision of specific web services for interaction on market principles between the providers and consumers of application packages. The suggested approach will be approved on the example of simulation applications in the field of nonlinear optics.

WaterML R package for managing ecological experiment data on a CUAHSI HydroServer

We present the design and development of a new WaterML R package that provides access to the Consortium of Universities for Advancement of Hydrologic Science (CUAHSI) Hydrologic Information System (HIS) HydroServer as a means for storing and managing data. The new WaterML R package is presented in terms of its functional requirements and design, with the express goal of providing support for four core web methods defined by the HydroServer WaterOneFlow web services specification. The system is tested in the context of data collected as part of a large ecological manipulation experiment. The resulting system allows research scientists to use a familiar statistical computation environment, R, together with the open source HydroServer software (for data archival and sharing). We also developed a new HydroServer data upload web service to facilitate data upload to a PHP version of HydroServer called HydroServer Lite directly from the WaterML R package presented here. Using the WaterML R package, the user can retrieve and analyze data from HydroServers of multiple organizations that are listed in the CUAHSI Water Data Center catalog and the Global Earth Observation System of Systems data catalog of the World Meteorological Organization. The new HydroServer Lite data upload API simplifies the upload of data to HydroServer Lite directly from the R environment.

How to Implement a Governmental Open Source Geoportal

By emerging the OGC web services technologies which caused server interoperability in geospatial fields, a rush toward implementing geoweb services commenced among most governmental enterprises. The massive geospatial information which has been produced in various offices during previous years, and which was not available for public customers because of protocol difficulties, now had a chance to be restructured as OGC specifications and be reachable to huge amount of keen clients via Internet platform. Increasing number of map presenters in web environment raised a search facility requirement in spatial data area. These kinds of search abilities are called “Geoportal”, which provides client applications that use several geo services such as catalogs and web map services. How to implement a suitable geoportal to meet the needs, has brought a set of hard challenges for governmental geospatial owners. In this study we present an overall concept of service oriented architecture and its consequence web service specifications and eventually web catalog services which are fundamentals of developing a geoportal. It also declares some experiments on importing/exporting data between geoportals, which is known as harvesting method.

Motivating service re‐use with a web service ontology learning

Purpose – The purpose of the research is to speed up the process of semantic web services by transformation of current Web services into semantic web services. This can be achieved by applying ontology learning techniques to automatically extract domain ontologies.Design/methodology/approach – The work here presents a Service Ontology Learning Framework (SOLF), the core aspect of which extracts Structured Interpretation Patterns (SIP). These patterns are used to automate the acquisition (from production domain specific Web Services) of ontological concepts and the relations between those concepts.Findings – A Semantic Web of accessible and re‐usable software services is able to support the increasingly dynamic and time‐limited development process. This is premised on the efficient and effective creation of supporting domain ontology.Research limitations/implications – Though WSDL documents provide important application level service description, they alone are not sufficient for OL however, as: they typic...

A systematic review on the functional testing of semantic web services

Semantic web services are gaining more attention as an important element of the emerging semantic web. Therefore, testing semantic web services is becoming a key concern as an essential quality assurance measure. The objective of this systematic literature review is to summarize the current state of the art of functional testing of semantic web services by providing answers to a set of research questions. The review follows a predefined procedure that involves automatically searching 5 well-known digital libraries. After applying the selection criteria to the results, a total of 34 studies were identified as relevant. Required information was extracted from the studies and summarized. Our systematic literature review identified some approaches available for deriving test cases from the specifications of semantic web services. However, many of the approaches are either not validated or the validation done lacks credibility. We believe that a substantial amount of work remains to be done to improve the current state of research in the area of testing semantic web services.

Semantic-based transaction model for web service

Cloud computing technology has become more and more utilized in business application in today's industrial fields. In general, many business systems developed based on web services are indeed heterogeneous software systems that process business data by complying with integrated business rules. Web services have until recently been regarded as software building blocks that can be assembled to construct the distributed business applications of the next generation and assist enterprises to promote operational efficiency and organizational flexibility. As a result, Web services can be employed to improve the integration of value chain processes and/or activities. However, Web services are usually implicit as a black box that prohibits users and developers from comprehending an actual scenario and present status inside the web service component as said developers deal with other associated heterogeneous components. Additionally, developers are unable to increase overall efficiency while integrating Web service components if they do not possess the ability to modify/improve the implementation scenario. This research first defines the component as corresponding state transitions that should be decomposed further into sub-transactions and semantic transactions, which can make possible re-implementation of the specific Web services in an efficient way and increase the overall throughputs for the new composite Web services. Secondly, this study implements an MTNet Project, which can be employed to assist developers' analysis and construction of the semantic models for Web services according to the previously described definitions. Last, the simulation experiment provided in this manuscript proved that the proposed semantic model can indeed improve the throughput and, consequently, decrease the delay time for concurrent transactions.

Use of Classification Algorithms for Semantic Web Services Discovery

Web services (WS) are used in different environments like enterprises, government and industry, providing tools for implementing complex distributed systems. Web service discovery allows a system to find services that meet the requirements of the users. One way to improve this type of discovery would consider not only the functional aspects of the required service, but also relevant aspects such as performance or availability to perform its functions. Moreover, this approach would allow a more efficient discovery process to obtain results closer to the user needs. In this paper we present an approach for Web service discovery through the use of machine learning algorithms for classification of Web services. For Web services matching our proposal takes into account quality of service (QoS) parameters, which include semantic information about each Web service. For semantic Web service specification we use the SAWSDL standard. Whereas the proposed UDDI standard was discontinued, among other reasons, due to limited syntactic Web service discovery, our approach brings important elements to the consolidation of semantic Web service discovery.

Automatic Verification of Data-centric Web Service Specifications

Amodel are proposed for modeling data-centric Web services which are powered by relational databases and interact with users according to logical formulas specifying input constraints, control-flow constraints and state/output/action rules. The Linear Temporal First-Order Logic (LTL-FO) formulas over inputs, states, outputs and actions are used to express the properties to be verified.We have proven that automatic verification of LTL-FO properties of data-centric Web services under input-bounded constraints is decidable by reducing Web services to data-centric Web applications. Thus, we can verify Web service specifications using existing verifier designed for Web applications.

XCEDE-DM: a neuroimaging extension to the W3C provenance data model

XCEDE-DM abstracts the implicit hierarchical data model described by the XCEDE schema into a technology agnostic syntax, which can then be serialized (e.g., into XML, JSON, RDF, etc.). Explicit data modeling facilitates broader use of web service specifications and database mediation services. XCEDE-DM is derived from the W3C PROV model [3], captures provenance as explicitly modeled relationships between entities, activities and agents. XCEDE-DM can capture complete details of a neuroimaging process including people and their roles, acquisition and analyses.

Monitoring web services’ quality of service: a literature review

Monitoring Quality of Service (QoS) compliance is an important procedure in web service environment. It determines whether users' expectations are met, and becomes the vital factor for them to decide whether to continue paying for the service or not. The monitoring is performed by checking the actual services performance against the QoS stated in Service Level Agreement (SLA). In relation to that, the need for monitoring vague QoS specifications in SLA has become more apparent nowadays. This paper reviews the published literature on web services QoS monitoring. A total of 60 selected articles were systematically analyzed. There were 23 of the articles selected through restrictive search criteria while the other 37 were selected based on unrestrictive search criteria. The review shows that little evidence exists on monitoring vague QoS specifications of web services. Providing ability for monitoring QoS that is specified vaguely in SLA could give new insights and implications to web services field. This paper concludes with some recommended future works to construct the theory and perform the empirical research.

Fault‐tolerant timestamp‐based two‐phase commit protocol for RESTful services

SUMMARYService‐oriented architecture provides interoperability and weak coupling features for software development. Representational state transfer (REST) is an architectural style that has attracted attention in the SOA domain as it allows the development of Web services based on original principles of the World Wide Web. Unlike Web service specifications, which are based on Simple Object Access Protocol and Web Services Description Language, REST does not provide ‘official’ standards to address non‐functional requirements of services, such as security, reliability, and transaction control. The timestamp‐based two‐phase commit protocol for RESTful service (TS2PC4RS) algorithm specifies concurrency control of RESTful services during a transaction. An extension of the TS2PC4RS specifies the concurrency control of the Web services considering the update operation to meet some business rules. However, neither algorithm addresses transaction control when failures occur. In long‐term transactions, failures can occur and compromise the success of Web service applications. Two common failures traditionally considered in the analysis of protocols are host and connection failures. The aim of this paper is to address fault tolerance for TS2PC4RS and its extension. A fault‐tolerant protocol based on timeout and log records is proposed. The fault‐tolerant protocol provides support for the host and connection failures that may occur during a transaction execution. The fault‐tolerant mechanisms are used to meet the application domain business rules that guide the behavior of RESTful services. We describe the protocol using scenarios when failures occur. Copyright © 2012 John Wiley & Sons, Ltd.

A web-based two-layered integration framework for smart devices

The explosions of Internet of Things industry have been bringing more and more smart devices (SDs) into business and people's daily life. This creates new opportunities to build applications that better integrate real-time state of the physical world and requires agility for the software to accommodate customers' requirements. Nevertheless, devices are usually provided by different manufacturers, and applications are independently constructed based on their own infrastructures with little interoperability. Web of Things concept has enabled the interoperability between devices by RESTful web service in a light-weight way; however, it make less efforts to discuss how to integrate devices into complex business environment. Service-Oriented Architecture and Business Process Management approach are becoming applicable to embedded real-world devices and provide flexible service composition. However, it is based on WS-* web service specification which is too heavy and complex for devices and not compatible to RESTful style. In such situation, integrating device into business application with simplicity and providing agility composition of service based on device are significant challenges. We propose a web-based two-layered integration framework that enables SD to integrate with each other via light-weight interface and other back-end applications into agile business process. A real-life use case on elderly care is studied in detail based on the framework.

A dynamic deontic logic for complex contracts

We present a dynamic deontic logic for specifying and reasoning about complex contracts. The concepts that our contract logic CL captures are drawn from legal contracts, as we consider that these are more general and expressive than what is usually found in computer science (like in software contracts, web services specifications, or communication protocols). CL is intended to be used in specifying complex contracts found in computer science. This influences many of the design decisions behind CL. We adopt an ought-to-do approach to deontic logic and apply the deontic modalities exclusively over complex actions. On top, we add the modalities of dynamic logic so to be able to reason about what happens after an action is performed. CL can reason about regular synchronous actions capturing the notion of actions done at the same time. CL incorporates the notions of contrary-to-duty and contrary-to-prohibition by attaching to the deontic modalities explicitly a reparation which is to be enforced in case of violations. Results of decidability and tree model property are given as well as specific properties for the modalities.

Flexible choreography-driven service selection

The greater and greater availability of services over the web motivates the growing interest in techniques that facilitate their re-use. A web service specification can be quite complex, including various operations and message exchange patterns. In this work, we propose a rule-based declarative representation of services, and in particular of WSDL operations, that enables the application of techniques for reasoning about actions and change, that are typical of agent systems. The representation allows reasoning on choreography roles and on possible role players, to the aim of selecting services which match in a flexible way with the specification. Flexible matches are an important tool that allows web service re-use but the proposals in the literature do not guarantee the preservation of those goals, that can be proved over the role specification. We show how to enrich various well-known matches so as to produce substitutions that preserve goals and that do not require service rollback. We also discuss the problem of the joint achievement of the individual goals of a group of choreography role players.

The Activity Chain Safety and Liveness Specification of Composite Web Services

Web service composition is most impressing method for development and deployment of e-business. Description and modeling the behavior requirements of composite Web services for users and verifying composite Web service compliance to specific requirements is an important key in design of services. But most work does not address the issue of how to model the requirements that the BPEL4WS processes are supposed to satisfy. The specifications in verification works are general temporal relation based on activity or scenario in essence. Distinguish with these work, we propose a novel concept of behavior specification based on activity chain in which granularity is between activity and scenario. Chain existence mode, chain absence mode are designed to express such behavioral requirements based on activity chain that is similar with safety or liveness specification based on activity respectively. Encode them on Labeled Transition System LTS and then give them exact operation semantics. Finally, an example is illustrated.

A Metamorphic Relation-Based Approach to Testing Web Services Without Oracles

Service Oriented Architecture (SOA) has become a major application development paradigm. As a basic unit of SOA applications, Web services significantly affect the quality of the applications constructed from them. In the context of SOA, the specification and implementation of Web services are completely separated. The lack of source code and the restricted control of Web services limit the testability of Web services, and make the oracle problem prominent. In this context, can one alleviate the test oracle problem, or effectively and efficiently test such Web services even without oracles? It is an important issue which has not been yet adequately addressed. To address the challenge of testing Web services, the authors propose a metamorphic relation-based approach to testing Web services without oracles. The proposed approach leverages so-called metamorphic relations to generate test cases and evaluate test results. To make the proposed approach practical and effective, the authors proposed a framework taking into account the unique features of SOA, and developed a prototype which partially automates the framework. Three case studies are conducted to validate the feasibility and effectiveness of the proposed approach. The work presented in the paper not only alleviates the test oracle problem of testing Web services, but also delivers an effective and efficient test technique without oracles.

Scalable Federated Broker Management for Selection of Web Services

Standard specifications of Web Services are mainly concerned with Web Service publishing and discovery. However, there is no standard regarding Web Service selection, which is very crucial for providers and clients. It will support clients in selecting Web Services based on required Quality of Web Service (QoWS) and support providers to remain competitive. Most of solutions on Web Service selection are very often based on a central component to make the selection decision, do not scale to the growing number of clients and Web Service providers, and/or lack trustworthiness. The objective of our approach is to support clients in selecting, and monitoring appropriate Web Services while increasing scalability, trust and reliability of Web Service selection. We propose a framework based on a federation of cooperative brokers. Each broker in the federation manages Web Services within its domain of expertise, and cooperates with its peers to select appropriate Web Services. We describe the federation management operations and our cooperative brokers QoS-aware selection algorithm. We propose certification and monitoring of Web Services as well as monitoring of brokers. The implementation and the experiments we have conducted evaluated the performance of our approach. The obtained results show that: the load is shared and distributed among brokers, a large number of client requests with different QoWS requirements were served, the architecture can scale up in order to include other brokers and/or other Web Services, and selection is guaranteed, trustworthy as it is supported by monitoring.

A fuzzy matchmaking approach for Semantic Web Services with application to collaborative material selection

A critical step in the process of reusing existing WSDL-specified services for building web-based applications is the discovery of potentially relevant services. However, the category-based service discovery, such as UDDI, is clearly insufficient. Semantic Web Services, augmenting Web service descriptions using Semantic Web technology, were introduced to facilitate the publication, discovery, and execution of Web services at the semantic level. Semantic matchmaker enhances the capability of UDDI service registries in the Semantic Web Services architecture and it is able to recognize various degrees of matching for Web services. Based on the Semantic Web Service framework, semantic matchmaker, specification matching and probabilistic matching, this paper proposes a fuzzy matchmaking approach for Semantic Web Services to support a more automated and veracious service discovery process in collaborative manufacturing environments. In the proposed approach, the membership function is set up on the semantic information annotated on WSDL specification of a web service, and the similarity of service objects is evaluated by the similarity degree of service attributes. A collaborative material selection case study in the die casting process for thermoelectric fan housing is used to illustrate the proposed approach.