Improving fairness of network bandwidth allocation for virtual machines in cloud environment

With the rapid development of cloud computing, data center's resource management has become a critical component in its business model. CPU, memory and network in a data center have many effective partitioning methods among the virtual machines that could offer high-efficiency, enhanced fairness and performance guarantee. However, in existing software based virtualization architecture (e.g., Xen), the network bandwidth is always decided by the number of connections, and no effective proportional share mechanism exists for the concurrently running virtual machines (VMs). Therefore, existing mechanism of network sharing will cause unfairness between VMs. In case that VMs should be given the same network bandwidth, there will be no such guarantee, especially when they establish different number of connections to outside world, even when the VMs are assigned with equal weight. In this paper, we present a mechanism that can improve the fairness of network bandwidth allocation in Xen para-virtualization in dynamic network environment. The experiment results demonstrate that every VM could share the network bandwidth almost according to its share even under real-world fluctuating network conditions.