Hierarchical Multi-resource Fair Queueing for Packet Processing

TL;DR

This paper introduces two novel multi-resource fair queueing algorithms, collapsed H-DRFQ and dove-tailing H-DRFQ, designed to support hierarchical scheduling for QoS guarantees in network middleboxes, backed by theoretical analysis and practical implementation.

Contribution

The paper proposes two new hierarchical multi-resource fair queueing algorithms that support hierarchical scheduling, a feature missing in existing algorithms, with proven theoretical guarantees and implementation.

Findings

Both algorithms provide hierarchical share guarantees to flows.

Dove-tailing H-DRFQ has a smaller upper bound on packet delay.

Experimental results confirm theoretical analysis.

Abstract

Various middleboxes are ubiquitously deployed in networks to perform packet processing functions, such as firewalling, proxy, scheduling, etc., for the flows passing through them. With the explosion of network traffic and the demand for multiple types of network resources, it has never been more challenging for a middlebox to provide Quality-of-Service (QoS) guarantees to grouped flows. Unfortunately, all currently existing fair queueing algorithms fail in supporting hierarchical scheduling, which is necessary to provide QoS guarantee to the grouped flows of multiple service classes. In this paper, we present two new multi-resource fair queueing algorithms to support hierarchical scheduling, collapsed Hierarchical Dominant Resource Fair Queueing (collapsed H-DRFQ) and dove-tailing H-DRFQ. Particularly, collapsed H-DRFQ transforms the hierarchy of grouped flows into a flat structure for flat scheduling while dove-tailing H-DRFQ iteratively performs flat scheduling to sibling nodes on the original hierarchy. Through rigorous theoretical analysis, we find that both algorithms can provide hierarchical share guarantees to individual flows, while the upper bound of packet delay in dove-tailing H-DRFQ is smaller than that of collapsed H-DRFQ. We implement the proposed algorithms on Click modular router and the experimental results verify our analytical results.