Management of customizable Software-as-a-Service in cloud and network environments

In recent years, there has been a rising interest in cloud computing, which is often used to offer Software-as-a-Service (SaaS) over the Internet. SaaS can be offered to clients at a lower cost as it is usually multi-tenant: many end users make use of a single application instance, even when they are from different organizations, reducing resource consumption. This however makes it increasingly hard to offer customization and tailoring options for clients, resulting in limited SaaS customizability. Some applications require high customizability, making it impossible to cost-efficiently offer them using cloud computing. In this thesis we design, develop and evaluate multiple approaches for the development and management of highly customizable multi-tenant SaaS, focusing on an approach that decomposes applications into components and on the modeling of the relations between application components, and present a methodology for managing these applications in cloud datacenters and (traditional and Network Function Virtualization-aware) network environments. Extensive evaluations using simulations based on existing commercial applications and generated scenarios show that the proposed approach can be used to increase multi-tenancy and save costs in the management of highly customizable SaaS.