Buffer Sizing Experiments at Facebook

In this paper, we present the results of several rounds of buffer sizing experiments at Facebook. We describe how we change buffer sizes in data center and backbone routers and study the impact of buffer sizes on several performance metrics, including flow completion time, latency, link utilization, and packet drop rate. Our observations suggest reducing buffers from millions of packets to a few thousand, and even a few hundred packets, does not lead to a general breakdown in network performance. In some cases we observed mostly tolerable degradation in some metrics (e.g., packet drop rates) and significant enhancements in others (e.g., latency).