Capacity-Aware Utility Function for SLA Negotiation of Cloud Services

Dynamic customers´ requirements and providers´ resources availability in the Cloud market make it inadequate static approaches to guarantee QoS levels and to define pricing. In this context, automatic negotiation guided by dynamic information and market conditions is a viable way to achieve high satisfaction levels for both parties. We propose to exploit capacity planning to support bilateral negotiation processes with the aim of optimizing the utility for service providers, by avoiding contracts that could incur in SLAs violations, keeping, at the same time, competitive prices. The proposed technique exploits a non-additive utility function defined in the region of acceptable SLA proposals, taking into account QoS, resources availability, costs and penalties. The paper shows the benefit of the proposed dynamic approach with respect to static approaches through a preliminary experimental analysis.