Optimal routing and bandwidth allocation for multiple inter-datacenter bulk data transfers

Bulk data transfers account for a large portion of inter-datacenter traffic, such as backups, propagation of bulky updates and migration of data. These bulk data transfers not only consume massive inter-datacenter bandwidth, but also increase the transmission cost of datacenters. To solve this problem, we first employ the max-min fairness to the design of optimal multiple bulk data transfers scheduling algorithm, which leverages the delay tolerance nature of bulk data and reuses dynamic leftover bandwidth to complete multiple bulk data transfers. Then we apply time-expanded technique to transform the problem under a dynamic network into a static network multi-flow problem, and solve it simultaneously from both routing assignment and bandwidth allocation through iterative linear programming approach. Extensive simulations are conducted on a real datacenter topology to demonstrate that our solutions can: 1) improve the network resource utilization; 2) minimize the average bulk data transfer completion time.