A User Driven Policy Selection Model

Abstract

Abstract. During Web service discovery phase, the policy selection step must occur to retrieve not only the Web services able to perform the required functionalities, but also Web services able to ensure a given quality level. Both service providers and service users define policies. The former list the supported service features and use a technical vocabulary (e.g., bandwidth, latency) whereas the latter identify the requirements using high level vocabulary closer to human users (e.g., speed). The aim of this paper is twofold. On one hand, it introduces a model for expressing quality according to both applications and human users perspectives. Such a model, compliant with the WS-Policy framework, not only mediates between the application and human user perspectives, but is also capable of considering the different importance assigned by the user to quality dimensions. On the other hand, the paper introduces a policy selection model based on the adopted quality model. According to this approach, human users can express quality requirements according to a high level language; these requirements are then matched against low level specifications of the service quality.

QoS-Aware Service Selection Using QDG for B2B Collaboration

“…After getting the service guideline of each business role in the business specification, what shall we do is to choose the best satisfied one from BRS depending on the service guideline. There exist many methods to choose a best one, such as the QoS-aware middleware supported by [10] [11], semantic QoS Selection Algorithm provided by Xia Wang [19], and the statistical model such as AHP method [12] [20]. We use AHP method provided by Saaty in 1970s to choose the best satisfied business role for its hierarchy nature satisfied our model much well and its mathematical property makes the weight of Quality Criteria more objective than the subjective ones [1].…”

On Automated Generation of Web Service Level Agreements

“…In a Web service environment, where users and providers might not know each others in advance, these documents must rely on the same language. In [8], a model able to express the quality of a Web service is discussed. The same model, discusses in the following, will be adopted in this work as well.…”

Policies and Aspects for the Supervision of BPEL Processes

“…At this stage we assume that the designer of the recovery strategy must indicate the endpoint of an equivalent service. For example, [10,11] discuss approaches for QoS-based Web service selection and Web service substitution with different interfaces are discussed. Additional Atomic Actions are: changeSupervisionRules, to modify how supervision is achieved and therefore to relax or tighten some constraints, changeParams, to modify the parameters associated with the considered supervision rule, changeProcessParams, to modify the parameters associated with the executing process, call, to call an external Web service, and processCallback, to directly invoke one of the event handlers supplied by the BPEL process.…”