Application-Aware Bandwidth Scheduling for Data Center Networks

Abstract

Recent study showed that many network applications require multiple different network flows to complete their tasks. Provisioning bandwidth to network applications other than individual flows in data center networks is becoming increasingly important to achieve user satisfaction on their received network services. Modern data center networks commonly adopt multi-rooted tree topologies. Equal-Cost Multi-Path (ECMP) forwarding is often used to achieve high link utilization and improve network throughput. Meanwhile, max-min fairness is widely used to allocate network bandwidth fairly among individual network flows. Today’s data centers usually host diverse applications, which have various priorities (e.g., mission critical applications) and service level agreements (e.g., high throughput). It is unclear how to adopt ECMP forwarding and max-min fairness in the presence of such requirements. In this paper, we first propose a flow-based scheduling mechanism (called FlowSch) to provide a prioritized Max-Min fair multiple path forwarding to improve link utilization and improve application performance. Then, we demonstrate and discuss that FlowSch may not perform effectively when network applications commonly use multiple network flows to accomplish their tasks. Accordingly, we design an application-aware scheduling mechanism (called AppSch) to tackle this challenge. AppSch can optimally allocate available bandwidth to satisfy application requirements. Our performance evaluation results show that FlowSch can improve flow throughput 10-12% on average and increase overall link utilization especially when the total demanded bandwidth is close or even exceeds the bisectional bandwidth of a data center network. However, when most applications rely on multiple network flows, AppSch can improve link utilization more effectively and reduce the application completion time 36-58%.