BwShare: Efficient bandwidth guarantee in cloud with transparent share adaptation

摘要

Bandwidth guarantee (BwG) is a highly desired feature in cloud data centers for enabling tenants (i.e., users) to achieve predictable performances. However, such a function currently is not commonly available in clouds since it potentially lowers the utilization efficiency of the network fabric (i.e., denoted network efficiency). The reasons lie in two aspects. First, tenants often present a time-varying and/or spatially-varying bandwidth demands. Second, the current cloud network architecture makes it hard to enable tenants to reuse unused bandwidth guarantees efficiently. To tackle these challenges, we propose BwShare, a novel bandwidth guarantee scheme in cloud data centers that can effectively improve the network efficiency at both the guaranteed level and the best-effort level in a synergized manner, while current approaches only adopt one of them. Such a design goal is achieved through two components: an adaptive bandwidth guarantee adaptation module (i.e., BGAdaptor) and a transparent work conservation module (i.e., WCEnabler). BGAdaptor improves the network efficiency at the guaranteed level by adjusting bandwidth guarantees among VMs of the same tenant based on traffic monitoring. WCEnabler works at the best-effort level by enabling VMs to reuse idled bandwidth efficiently and freely without disrupting bandwidth guarantees. The two modules can also facilitate each other's performance. Extensive experiments show that BwShare can effectively improve the network efficiency while providing the function of bandwidth guarantee in cloud data centers. (C) 2020 Elsevier B.V. All rights reserved.