Deadline-aware bandwidth sharing by allocating switch buffer in data center networks

Abstract

Most of today's data center applications are sensitive to latency. In this paper, a Deadline-aware bandwidth Sharing mechanism by Allocating switch Buffer (DSAB) is proposed to satisfy the deadline requirements of flows. As the existing work SAB does, DSAB also leverages the feature that the buffer size of a switch port is usually much larger than the product of bandwidth and round trip delay in data center networks. The basic idea of DSAB is to allocate switch buffer to deadline-sensitive flows in priority and the remaining buffer is fairly allocated to background flows. However, this method will possibly lead to bandwidth wastage in topologies with multiple bottlenecks. Therefore, enlightened by the pre-authorization method in credit card systems, we propose a Pre-Authorization (PA) algorithm to address this problem. The PA algorithm allows switches take back the extra allocated bandwidth by adding a bandwidth confirmation phase after the bandwidth request phase. End hosts and switch functions of DSAB is implemented in Linux kernel and NetFPGA platform, respectively. The results of experiments conducted in a real small testbed indicate that DSAB can indeed satisfy the deadline requirements of deadline-sensitive flows by allocating switch buffer to them in priority.