An Integrated Platform for Dynamic Adaptation of Multi-tenant Single Instance SaaS Applications

Software-as-a-Service (SaaS) has recently been adopted by many organizations to get their work done through subscription-based services. To leverage economies of scale, software and hardware resources are shared among multiple tenants who have different requirements that rapidly change with time. Responding to tenants' diverse needs requires SaaS providers to carefully manage software variability so that every tenant feels like having a distinct instance of the application. Tenants' evolvable needs require the SaaS instance to dynamically adapt. This paper presents an integrated platform that facilitates the dynamic adaptation of Multi-Tenant Single Instance SaaS applications and supports runtime tenants' configurations customization. The proposed platform is based on three concepts: Service-Orientation, Software Product Lines (SPLs), and Model Driven Architecture (MDA). The proposed solution spans over two dimensions: Feature-level variability management and runtime variability management. We propose raising the level of abstraction in which the whole adaptation process is addressed to better manage customization. The feasibility of the approach is illustrated via a functioning prototype. A realistic SaaS application was used to exercise the different adaptation scenarios and evaluate the platform prototype implementation.