Research On Quality Of Service For Web Services

At present, software services and software services collaborative with the representative of web services has become a typical internet application form based open network environment. Web services based on open standards, a cross-platform, cross-language, and service-oriented application and integration of superiority, web services applications, however, didn't expect widespread optimism. The critical reason is the issue that quality of services for web services.Research of QoS on the current web services mainly in the service of the system to achieve the performance indicators, but ordinary users of web services evaluating and selecting is more concerned about the QoS indicators of business application layer. To this end, this paper presents a web services QoS model, from the business layer, services layer and system layer three different perspectives of the whole expression of web services QoS information.Existing web services description model didn't pay attention to the description of QoS, the study of QoS ontology is concerned common QoS attributes, neglected the role of web services applications relevant to the area of QoS attributes in the evaluation and selection of web services. Based on comparative analysis of existing web services description models on the basis of advantages and disadvantages, drawing on research results of QoS ontology, this paper designing a scalable QoS description model of web services, perfecting description of the existing web services models.Based on web services description model of QoS, this paper presents an ideal of different levels service matchmaking, service selection process will be divided into three steps: service functional information classification pretreatment; services functional classification selection; QoS optimal services selection. According to the actual situation of user's requests, this paper focuses on the optimal QoS services selection algorithm.Finally, this paper implements the prototype system of web services QoS selection based broker model, testing the recall and precision rate of the different levels service matchmaking algorithm and the runtime performance of the prototype system.