On Mitigating TCP Incast in Data Center Networks
TCP Incast, also known as TCP throughput collapse, is a term used to describe a link capacity under-utilization phenomenon in certain many-to-one communication patterns, typically in many datacenter applications. The main root cause of TCP Incast analyzed by prior works is attributed to packet drops at the congestion switch that result in TCP timeout. Congestion control algorithms have been developed to reduce or eliminate packet drops at the congestion switch. In this paper, the performance of Quantized Congestion Notification (QCN) with respect to the TCP incast problem during data access from clustered servers in datacenters are investigated. QCN can effectively control link rates very rapidly in a datacenter environment.