Promenade: Proportionally Fair Multipath Rate Control in Datacenter Networks with Random Network Coding

Abstract

In today's datacenter topologies, there exist multiple equal-cost paths between each pair of communicating virtual machines. Yet, splitting flows and routing them along multiple paths may lead to packet reordering, which may affect the performance of TCP. In this paper, we propose Promenade, a new protocol that uses random network coding to mitigate the negative effects of packet reordering, while at the same time achieving weighted proportional fairness in bandwidth allocation across different tenants. To achieve weighted proportional fairness when allocating bandwidth to tenants, the problem of rate control is formulated as a convex optimization problem, and Promenade uses its distributed solution as a theoretical foundation to design its bandwidth allocation protocol. With our real-world implementation of Promenade in the Mininet testbed, we are able to show that Promenade is able to achieve weighted proportional fairness in its rate control when individual flows are split into multiple paths.