Dynamic resource allocation with management objectives—Implementation for an OpenStack cloud

We report on design, implementation and evaluation of a resource management system that builds upon OpenStack, an open-source cloud platform for private and public clouds. Our implementation supports an Infrastructure-as-a-Service (IaaS) cloud and currently provides allocation for computational resources in support of both interactive and computationally intensive applications. The design supports an extensible set of management objectives between which the system can switch at runtime. We demonstrate through examples how management objectives related to load-balancing and energy efficiency can be mapped onto the controllers of the resource allocation subsystem, which attempts to achieve an activated management objective at all times. The design is extensible in the sense that additional objectives can be introduced by providing instantiations for generic functions in the controllers. Our implementation monitors the fulfillment of the relevant management metrics in real time. Testbed evaluation demonstrates the effectiveness of our approach in a dynamic environment. It further illustrates the trade-off between closely meeting a specific management objective and the associated cost of VM live-migration.