Application Multi-Tenancy for Software as a Service

Abstract

Software as a service has evolved as a new software deployment paradigm in the cloud, which offers information technology services dynamically, "on-demand". Application Multi-tenancy in SaaS leads to improved resource utilization and reduces overall application costs by sharing the same applications, resources and data services through multiple tenants. In this paper a graph-based approach called SaaS Level Application Multi Tenancy graph is proposed to represent the multi-tenant aspects of the SaaS model of cloud environment formally. The proposed approach will facilitate the analysis of service interaction paths for accessing shared sets of services in SaaS by the multiple tenants. The proposed approach is capable enough to model several kinds of tenant like isolated tenant, shared tenants with single or multiple data services and multiple tenants in SaaS. Further, several metrics are defined for the proposed approach to describe the essential features of multi-tenant SaaS applications. The expressiveness of the proposed approach is illustrated using several examples and a detailed case study.