A Dynamic Network Bandwidth Allocation Mechanism under Network QoS Constraints

A virtualized cloud platform may host several cloud services/applications simultaneously. Each hosted cloud service usually runs on a virtual cluster, consisting of several virtual machines (VMs) with a virtual network. In many cases, the virtual clusters share the overall physical network bandwidth. Thus, the quality of the cloud services sharing the same physical networks can be seriously affected when one of the cloud services produces a high traffic load. In this paper, we propose a mechanism to solve the mentioned issue. The proposed mechanism utilizes a logically centralized QoS controller to allocate network bandwidth to virtual clusters dynamically. The QoS controller uses a monitor to continuously gather network usage of each VM, and calculates the bandwidth consumption in the granule of virtual clusters. A Rate Limiter is bundled to each physical machine for triggering bandwidth re-distribution. The proposed mechanism is implemented on the OpenStack-based cloud platform, SAMEVED, which is developed to support on-line network security experiments. We implemented several network bandwidth re-distribution strategies on the proposed mechanism. We emulate the real network flows in the platform, and the experiment results show that, the proposed approach can effectively reduce nearly one third of packet loss rate when running a video streaming service in a high network traffic scenario.