Preventing passive TCP timeouts in data center networks with packet drop notification

Data centers are considered as the indispensable infrastructure for cloud services nowadays. However, large-scale data centers using the traditional TCP protocol may experience some performance issues, such as TCP Incast and long query completion times. It is shown that the fundamental cause of these problems is that the existing TCP protocols are unable to effectively detect packet losses in the network, which always causes timeouts in data centers. In this paper, we present the packet drop notification, a mechanism that can accurately inform senders about packet losses. So the passive timeouts can be avoided, and the packets can be retransmitted immediately. This mechanism is simplified when used with the software-defined networking technique, which is a promising technology to build a more customizable control plane, in data center networks. Simulation results show that the precise packet drop notification can improve the goodput of high fan-in applications, and therefore effectively reduce the task completion times. Further, we evaluate the fairness of the TCP with notification, and show that it can work well with other TCP variants.