SLA based business-driven adaptive QoS maintenance mechanism for multi-tier service in virtualized IT environment

In view of the adaptive QoS maintenance issue for multi-tire virtualized IT Service, basing IT resource regulation only on QoS reference value leads to suboptimal decision. This paper proposes an online QoS maintenance mechanism for multi-tier IT service system in order to obtain the optimal global business utility. We build a novel business utility model which concerns both the business revenue and loss related to service performance and availability for multi-tier virtualized IT service. Then we establish the resource allocation mechanism with the assistance of our proposed novel IT-business metrics mapping. This approach can adaptively maintain the QoS in a reasonable range by dynamically regulating the virtualized IT resource. The experimental simulation shows that our approach is superior to the conventional approach since the overall business utility of all service levels stays on a relative high level.