In cloud computing, multi-tenancy is concomitant with scalability in the sense that sharing a single deployment instance between many customer organizations (tenants) maximizes the utilization of the available resources. However, this also introduces the need to customize the application to the (slightly) different requirements of different tenants. In the context of workflow-based SaaS offerings, this is not straightforward to accomplish without compromising scalability or manageability of the offering.   In this paper, we present a middleware for multi-tenant customization of workflows that enables software providers (i) to decrease coupling of multi-tenant customization concerns and workflow design for better manageability, (ii) to activate tenant preferences at runtime, but (iii) without incurring a scalability penalty. We validate a prototype implementation of our middleware in the context of a realistic SaaS application, evaluate its scalability, and extensively compare the results with related work confirming that the proposed middleware indeed supports customization of workflows in a significantly more scalable fashion.
['Majid Makki', 'Dimitri Van Landuyt', 'Stefan Walraven', 'Wouter Joosen']
Scalable and manageable customization of workflows in multi-tenant SaaS offerings