Novel time related quality of service criteria

摘要

The orientation towards web service technology gives a raise to huge number of functionally similar web services. Hence, quality of service is becoming more important and even essential in web service technology as a distinctive criterion. Generally providers have sufficient information about the really provided quality, however, clients don't. Service level agreements that define the relationship between consumer and provider are the only way to express their functional as well as non-functional requirements and to rise notifications to providers in case of violation. One of the major challenges in this regard is to provide ways to assign responsibilities of each party (client / provider) in such case. The idea is to include expectations for measurable and only-provider related attributes (accessibility, availability, throughput,...). Time is a common measure of performance, but it is reduced into a unique temporal attribute: the response time. The latter depends simultaneously on client, network and provider side. Thus, we introduce three temporal attributes namely connection time, transport time and execution time. In this work, we study quality attributes and propose a quality model which includes a set of selected measurable and only provider related attributes and defined temporal ones. Experiments prove the significance of temporal attributes separation in web service selection and duties.