Maria Beatriz Felgar de Toledo

A Web Service Architecture Providing QoS Management

Although Web service technology allows the development and execution of distributed applications, it still lacks facilities to deal with quality of service (QoS). Consumers may require services with particular nonfunctional characteristics and expect quality level guarantees. The goal of this paper is to propose an extended Web service architecture supporting QoS management for Web services. It includes brokers to facilitate service selection according to functional and non-functional requirements and monitors to verify QoS attributes. The main contributions of this approach are the use of the Web services policy framework (WS-Policy) standard to enhance the service specification with QoS policies and an extension to the universal description discovery & integration (UDDI) standard for QoS-enriched Web service publication and discovery

Semantics-enriched QoS policies for web service interactions

Web service technology provides an infrastructure for developing distributed systems and performing electronic business operations within and across organizational boundaries. It is still evolving. Currently, it is lacking mechanisms to deal with Quality of Service (QoS). Service consumer requirements may include functional and non-functional aspects. The Web Services Description Language (WSDL) and Universal Description Discovery & Integration (UDDI) standards support the specification, publication and discovery of Web services based only on functional aspects. The goal of this paper is to propose an approach for supporting Web service interactions. Brokers are employed to facilitate the partnership establishment between service consumers and providers. They select services in UDDI registries according to consumer functional and non-functional requirements. The main contributions of this paper are an extension to the Web Services Policy Framework (WS-Policy) standard to complement WSDL descriptions with semantics-enriched QoS policies using the Ontology Web Language (OWL) and ABLE Rule Language (ARL) standards, and an extension to the UDDI standard to include QoS policies.

WS-CONTRACT ESTABLISHMENT WITH QOS: AN APPROACH BASED ON FEATURE MODELING

Electronic contracts describe inter-organizational business processes in terms of supply and consumption of electronic services (commonly Web services). The establishment of e-contracts in a particular business domain usually involves a set of well-defined common and variable properties. These properties are not fully exploited by the existing e-contract establishment approaches. Feature modeling is a software engineering technique that has been widely used for capturing and managing commonalities and variabilities of product families in the context of software product line. This paper presents a feature-based approach to support Web services e-contract (WS-contract) establishment. The approach aims at improving the information structure and reuse of WS-contracts, including the QoS attributes. Features are used to represent possible WS-contract elements in order to drive WS-contract template instantiation, thus acting as a configuration space manager. A toolkit named FeatureContract was developed to autom...

A Web Service Privacy Framework Based on a Policy Approach Enhanced with Ontologies

The Web service technology facilitates the automated use of electronic services on the Web. It offers benefits, mainly the system interoperability support, but it also raises privacy concerns on the handling of sensitive data about service consumers. For instance, in electronic commerce applications, privacy protection is frequently a major consumer requirement. It includes concerns such as, how sensitive data are used and who has access to them. These concerns have been increasingly discussed. However, there is not a standard privacy framework for Web services. This paper proposes a Web service privacy framework based on a policy approach enhanced with ontologies. It uses different Web standards for supporting privacy protection, including the platform for privacy preferences (P3P), the Web services policy framework (WS-Policy) and the Web ontology language (OWL).

Web service security management using semantic web techniques

The importance of the Web service technology for business, government, among other sectors, is growing. Its use in these sectors demands security concern. The Web Services Security standard is a step towards satisfying this demand. However, in the current security approach, the mechanism used for describing security properties of Web services restricts security policy specification and intersection. In environments that include loosely-coupled components, a rich description of components is needed to determine whether they can interact in a secure manner. The goal of this paper is to propose a security approach for Web services, which combines Web Services Policy Framework policies and a Web Ontology Language ontology to overcome the limitation of the current syntactic approach. The main contribution of this paper is an extended approach based on semantics-enriched security policies.

A survey on reuse in the business process management domain

Business process management (BPM) is an important technological support to improve organisation competitiveness. BPM can benefit from reuse approaches and techniques at several stages of the business process life cycle in order to increase dynamism, flexibility and competitiveness. Existing reuse techniques from areas such as software engineering can be extended to this emerging domain. This paper presents the results of a literature review of reuse in the BPM domain. It aims to provide an overview and an overall discussion of most relevant research projects that have been developed applying reuse in BPM.

Towards a base ontology for privacy protection in service-oriented architecture

The service consumers confidence in the protection of their privacy is an important factor for the success of electronic services (e-services). It may increase if the service provider offers a description of its data practices. This description can be compared to what the consumer defines as appropriate practices. To allow the exchange of privacy-related descriptions and automatically compare them, the parties involved in the interaction should be able to use a common vocabulary. The goal of this paper is to present a base privacy ontology for e-services and a privacy framework for service-oriented architecture (SOA). The ontology offers a base vocabulary that can be extended to create ontologies specific to a given service domain and operating environment. The framework uses ontologies so that it can support service selection considering the consumers privacy requirements. It extends SOA with provider policies and consumer preferences based on privacy ontologies.

Quality of Service Management for Web Service Compositions

Typically, scientific applications have to be distributed across computational grid infrastructures. These applications can use existent grid services. Service components in this kind of application may have different computational platforms that should interoperate. This interoperability is supported by the Web service technology. Thus, currently, some Web service standards are used in several service-oriented grid infrastructures. The Web Services Business Process Execution Language (WS-BPEL) is an example of a standard that can be used in this context to support the definition of scientific workflows. However, its approach for building service compositions does not consider quality of service (QoS) issues. This paper proposes an approach for building service compositions according to QoS characteristics expressed using the Web services policy framework (WS-policy).

Web service e-contract establishment using features

Electronic contracts describe inter-organizational business processes in terms of supply and consumption of electronic services (commonly Web services). In a given contract domain, it is usually possible to identify a set of well-defined common and variation points. Feature modeling is an ontology-like technique that has been widely used for capturing and managing commonalities and variabilities of product families in the context of software product line. This paper proposes a feature-based approach in order to decrease the complexity in Web service e-contract establishment. The feasibility of the approach is shown by a case study carried out within the telecom context and based on experimental software engineering concepts.

Supporting QoS Negotiation with Feature Modeling

Feature modeling is a technique that has been widely used for capturing and managing commonalities and variabilities of product families in the context of software product line. This paper presents a feature-based approach to be applied in QoS negotiation during the establishment of a Web services e-contract. Its motivation is that the e-negotiation process, aiming at defining attributes and levels for QoS --- in a particular business domain, usually involves a set of well-defined common and variation points.