A Fine-grained and Transparent Congestion Control Enforcement Scheme

Abstract

In practice, a single TCP congestion control is often used to handle all TCP connections on a Web server, e.g., Cubic for Linux by default. Considering complex and ever-changing networking environment, the default congestion control algorithm may not always be the most suitable one. Adjusting congestion control usually to meet different networking scenarios requires modification of servers' TCP stacks. This is difficult, if not impossible, due to various operating systems and different configurations on the servers. In this paper, we propose Mystique, a lightweight and flexible scheme that allows administrators (or operators) to deploy any congestion control schemes transparently without changing existing TCP stacks on servers. We have implemented Mystique in Open vSwitch (OVS) and conducted extensive test-bed experiments in public cloud environments. We have extensively evaluated Mystique and the results have demonstrated that it is able to effectively adapt to varying network conditions, and can always employ the most suitable congestion control for each TCP connection. Mystique can significantly reduce latency by up to 37.8% in comparison with other congestion controls. 1 Those Web servers can be either physical servers or VMs in cloud datacenters. For consistency, we use "Web server" to refer both cases.

Mystique: A Fine-Grained and Transparent Congestion Control Enforcement Scheme

“…In summary, the main contributions of this paper are threefold [12]: 1) We conduct extensive studies to show that no single congestion control suits all network conditions. We also provide a recommendation of the most suitable congestion control for certain network conditions.…”