Proactive coordination for low-congestion multi-path datacenter networks

Abstract Modern datacenters involve a rich mix of workloads, each of which puts forward different service-level objective, including high throughput, low latency, etc. Currently, most datacenters introduce statistical multiplexing technology and oversubscription to the network design to lower the total cost, which can easily lead to the occurrence of network congestion, especially when the network is highly occupied by throughput-intensive workloads. This paper describes ProCAM, a proactive congestion avoidance mechanism for datacenter networks. As throughput-intensive flows are the chief culprit of network congestion, ProCAM adapts the multi-path routing to control transmission bandwidth and utilizes the predictability of throughput-intensive flows to prearrange optimal coordinate scheme (desynchronize the sending time of concurrent long-flows) beforehand as a proactive manner, by solving the low-congestion transmission model which minimizes network-wide host-to-host transmission latency from a global perspective. In this way, queue length in buffers can be kept at a low level and the performance of latency-sensitive flows can be guaranteed. In the evaluation experiments based on simulation with Mininet and SDN controller Ryu, the extensive simulations show that the proposed ProCAM can achieve high throughput with nearly zero packet loss and low latency when the network is highly occupied.