Nxt-Max: for supporting VDC-based maximum redundant bandwidth allocation in cloud datacenter

In cloud datacenter, work-conserving bandwidth offering benefits the network sharing of multiple virtual datacenters (VDCs). The lack of concrete network resources prevents tenants from predicting lower bounds on the performance of their applications. Prior works concentrate on efficient and scalable bandwidth allocation algorithms for VDCs. However, per-VDC redundant bandwidth is ignored, which is crucial to work-conserving bandwidth offering. In this paper, Nxt-Max, a VDC-based redundant bandwidth allocation framework is designed that ensures per-VDC maximum redundant bandwidth allocation by integrating online allocation with offline allocation. To make online bandwidth allocation efficient, a heuristic online parallel bandwidth allocation algorithm is proposed by dividing the whole allocation spaces into independent pods. Coupled with smart offline adjustment, the released network graph, and greedily migrate VDCs with the least redundant bandwidth are constructed, advancing the overall underlying network utilization. Simulations demonstrate that VDC allocation achieves high network utilization, low time complexity, and per-VDC maximum bandwidth allocation.