MPICC: Multi-Path INT-Based Congestion Control in Datacenter Networks

Network congestion causes severe transmission performance loss. Congestion control is the key to achieve low latency, high bandwidth and high stability. Due to the high regularity of topologies, datacenter networks contain abundant resources of equal-cost paths inherently and have huge potential for high-bandwidth transmission. Taking in-network telemetry (INT) information as the congestion signal, congestion control algorithms can monitor the network based on precise link load data. Hence the INT-based algorithm is the focus of recent high-precision congestion control research. However, existing INT-based congestion control algorithms handle the single-path transmission between the sender and the receiver, which cannot make full use of the abundant equal-cost paths resources in the network. In this paper, we make the first attempt to propose a multi-path INT-based congestion control algorithm, called MPICC. Compared with the most advanced INT-based congestion control algorithm HPCC, our method realizes multi-path coordinated transmission of data packets in datacenter networks. We conduct extensive experiments under various workloads to evaluate the performance of MPICC. The experimental results show that under the condition of ensuring high throughput of end hosts, MPICC is able to use multi-path to transmit data packets, which greatly reduces the flow completion time (FCT) of the flow in the network. Specifically, under three common datacenter workloads, Cache Follower, Web Search and Web Server, MPICC reduces the average flow completion time of the network by 20.1%, 14.4%, and 39.5%, respectively, and shortens the 97th-percentile flow completion time by 39.9%, 18.9% and 57.9%, respectively.