An Optimal Selection Approach for a Multi-tenancy Service Based on a SLA Utility

The service models of cloud computing include software as a service (SaaS), platform as a service (PaaS) and infrastructure as a service (IaaS). Multi-tenancy service is one service concept of a SaaS. A tenant can customize personal requirements in a multi-tenancy service configuration by negotiating with the service provider. The configuration items are recorded in a Service Level Agreement (SLA). Due to the popularity of software services, there are various services for the tenant to choose from. How to select a reasonable service from various multi-tenancy services has become an important issue. Therefore, this research explores the utility function of the SLA and uses an approach for the optimal selection of a multi-tenancy service based on a SLA utility function. The approach formalizes the SLA and discusses a utility model for the SLA's configuration items. Then, the multi-criteria decision analysis method is used to discover the reasonable selection order of multi-tenancy services. The selection order helps a tenant acquire a reasonable multi-tenancy service which meets his personal requirements.