A QoS&SLA-Driven Multifaceted Trust Model for Cloud Computing

Abstract

Quality of Service (QoS) plays a vital role in cloud computing while Service Level Agreements (SLA) to a service contract is indispensable as well. Selecting a trusted cloud service based on service performance, thus, is raising fundamental concern. This work presents a QoS&SLA-driven multifaceted trust model for efficiently evaluating the trustworthiness of a cloud service in the light of its multiple differential service attributes. Owing to the uncertainty of QoS, the interval number theory is naturally introduced into our trust model. In the trust evaluation, moreover, an adaptive weight adjustment method that depends on connection number is exploited to dynamically accommodate their respective factors. The proposed trust model is the composition of two types of trust metrics, which are QoS trust and user satisfaction trust. QoS trust, specifically, that indicates the level of actual performance of the cloud service. User satisfaction trust virtually reflects to what extent actual service performance is in accord with SLA. Finally, we assess the proposed trust model based on real datasets derived from CloudHarmony, which makes the approach more objective and effective for cloud computing.