Hierarchical Multi-resource Fair Queueing for Network Function Virtualization

Abstract

As the volume of traffic flows surges, providing Quality-of-Service (QoS) guarantees to flows by fair queueing has never been more challenging in Network Function Virtualization (NFV). There has been a recent effort in both industry and academia to develop fair queueing algorithms across multiple resources in NFV. However, all existing works fail to support hierarchical scheduling, a crucial feature that also provides QoS guarantees to grouped flows on tenant boundaries. In this paper, we present two new multi-resource fair queueing algorithms that support hierarchies, collapsed Hierarchical Dominant Resource Fair Queueing (collapsed H-DRFQ) and dove-tailing H-DRFQ, both of which provide hierarchical share guarantees. Through formal analysis, we find that the dove-tailing H-DRFQ outper-forms collapsed H-DRFQ by providing a smaller delay bound. However, according to the simulation results, both algorithms have their pros and cons. Dove-tailing H-DRFQ benefits to the flows with more complex hierarchies, while collapsed H-DRFQ is better for the flows with simpler attribution structures. Meanwhile, our simulation shows that both H-DRFQ algorithms can achieve near-perfect fairness.