A Platform Independent Access Control Metamodel for Web Services

Web services provide platform independent communication through an XML-based standard family. The major software vendors released their own SOA products implementing these standards. However, the configuration of the WS-* protocols differs from product to product. Matching these configurations between different products can be a very tedious task. Security protocols are among the most complicated protocols to configure, especially if access control is also required. Although the XACML standard aims to solve this task, its rules and policies described in XML are not very user friendly, and XACML has a very poor support in the major SOA products. Therefore, we have developed a platform independent metamodel for describing distributed systems of web services. From models described in this metamodel the platform specific configurations and program codes can be easily generated for the various SOA products, increasing the productivity of the development. This article introduces an access control extension to this metamodel

0010/2011 - WS-Policy: conceitos e propostas de uso

Em Arquitetura Orientadas a Serviço (SOA - Service-Oriented Architecture) a descoberta do serviço que melhor antende às necessidades do consumidor é um desa-fio. O padrão UDDI é apresentado como principal padrão para armazenamento das descrições dos serviços, permitindo consultar serviços, divulgar atualizações sobre os mesmos e recuperar informações para invocação. No entanto, este padrão não atende a todos os requisitos dos consumidores. Dessa forma, autores propõem extensões deste padrão empregando ontologias e WS-Policy para descoberta de serviços, bem como para monitoramento de execução de serviços. Este trabalho apresenta os principais conceitos de WS-Policy bem como trabalhos da literatura que propõe o uso deste padrão e evolução do mesmo para descoberta de serviços, monitoramento de serviços e definição de atributos de qualidade de serviços (QoS)

An Extensible and Personalized Approach to QoS-enabled Semantic Web Service Discovery

We present a framework for the autonomous discovery and selection of Semantic Web services based on their QoS properties. The novelty of our approach is the wide use of semantic technologies for a customizable discovery, which enables both the service users and providers to flexibly specify their matching models for QoS and the corresponding environmental conditions. In the presented approach, the discovery and ranking of services can be personalized via the use of domain ontologies detailing the user's preferences and the provider's specification. The discovery component is modeled as an adaptive query processing system in which the basic steps of filtering, matchmaking, reputation-based QoS assessment, and ranking of services correspond to logical algebraic operators, which facilitates the introduction of different discovery algorithms and the automatic generation of appropriate parallelized matchmaking evaluations, enabling the scalability of our solution up to unpredictable arrival rate of user queries against high numbers of published service descriptions in the system

On Using WS-Policy, Ontology, and Rule Reasoning to Discover Web Services

This paper proposes an approach to behaviour-based discovery of Web Services by which business rules that govern service behaviour are described as a policy. The policy is represented in the form of ontological information and is based on actions relating to the service and conditions for performing them. The standard WS-Policy is used to associate such a policy to the Web Service. With a framework that extends standard discovery by UDDI, service consumers can query for Web Services by specifying business constraints. The policy of the Web Service will be evaluated against the consumer’s query by using OWL ontology querying engine and a rule-based reasoning module. By considering business rules in addition to the conventional attribute-based search by UDDI, the approach will enable more satisfactory discovery results that better fit service consumers’ requirements

On Using WS-Policy, Ontology, and Rule Reasoning to Discover Web Services

This paper proposes an approach to behaviour-based discovery of Web Services by which business rules that govern service behaviour are described as a policy. The policy is represented in the form of ontological information and is based on actions relating to the service and conditions for performing them. The standard WS-Policy is used to associate such a policy to the Web Service. With a framework that extends standard discovery by UDDI, service consumers can query for Web Services by specifying business constraints. The policy of the Web Service will be evaluated against the consumer’s query by using OWL ontology querying engine and a rule-based reasoning module. By considering business rules in addition to the conventional attribute-based search by UDDI, the approach will enable more satisfactory discovery results that better fit service consumers’ requirements

Quality of service support for service discovery and selection in service oriented computing environment

Service oriented computing (SOC) represents a new generation of web architecture. Central to SOC is the notion of services, which are self-contained, self-describing, modular applications that can be published, located, and invoked across the Internet. The services represent capability, which can be anything from simple operations to complicated business processes. This new architecture offers great potential for e-commerce applications, where software agents can automatically find and select the services that best serve a consumer's interests. Many techniques have been proposed for discovery and selection of services, most of which have been constructed without a formal Quality of Service (QoS) model or much regard to understanding the needs of consumers. This thesis aims to provide QoS support for the entire SOC life cycle, namely: (i) extend current approaches to service discovery that allow service providers to advertise their services in a format that supports quality specifications, and allows service consumers to request services by stating required quality levels, (ii) support matchmaking between advertised and requested services based on functional as well as quality requirements, (iii) perform QoS assessment to support consumers in service selection. Many techniques exists for performing QoS assessment, most of which are based on collecting quality ratings from the users of a service. This thesis argues that collecting quality ratings alone from the users is not sufficient for deriving a reliable and accurate quality measure for a service. This is because different users often have different expectations and judgements on the quality of a service and their ratings tend to be closely related to these expectations, i.e., how their expectations are met. The thesis proposes a new model for QoS assessment, based on user expectations that collects expectations as well as ratings from the users of a service, then calculates the QoS using only the ratings which were judged on similar expectations.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Quality of service support for service discovery and selection in service oriented computing environment

Service oriented computing (SOC) represents a new generation of web architecture. Central to SOC is the notion of services, which are self-contained, self-describing, modular applications that can be published, located, and invoked across the Internet. The services represent capability, which can be anything from simple operations to complicated business processes. This new architecture offers great potential for e-commerce applications, where software agents can automatically find and select the services that best serve a consumer's interests. Many techniques have been proposed for discovery and selection of services, most of which have been constructed without a formal Quality of Service (QoS) model or much regard to understanding the needs of consumers. This thesis aims to provide QoS support for the entire SOC life cycle, namely: (i) extend current approaches to service discovery that allow service providers to advertise their services in a format that supports quality specifications, and allows service consumers to request services by stating required quality levels, (ii) support matchmaking between advertised and requested services based on functional as well as quality requirements, (iii) perform QoS assessment to support consumers in service selection. Many techniques exists for performing QoS assessment, most of which are based on collecting quality ratings from the users of a service. This thesis argues that collecting quality ratings alone from the users is not sufficient for deriving a reliable and accurate quality measure for a service. This is because different users often have different expectations and judgements on the quality of a service and their ratings tend to be closely related to these expectations, i.e., how their expectations are met. The thesis proposes a new model for QoS assessment, based on user expectations that collects expectations as well as ratings from the users of a service, then calculates the QoS using only the ratings which were judged on similar expectations