Virtual Machines' Load-Balancing in Inter-Clouds

Virtualization is the fundamental technology enabler behind Cloud Computing (CC) whose services are provided via the instantiation of Virtual Machines (VMs). These instantiations follow mostly a stochastic pattern, depending mainly on the ad hoc timing when users request and release these services, and thus generating a dynamic load on the CC compute nodes. To cope with this inherent dynamicity, a load-balancing scheme is substantial for an optimal CC platform operation. Ideally, VMs need to be dynamically migrated from a Cloud site to another in order to balance between Cloud sites witnessing heavy and light loads. In this paper, we shed further light on inter-Cloud load-balancing subtleties, and delineate its strong correlation to VMs migration. We propose a novel idea for live VM-migration (soft-handoff VM migration) inspired from mobile computing. As a prerequisite, we implemented a simple load-balancing scheme, consisting on real-time tracking of VMs load in a real-world testbed interconnecting two Cloud sites.