SCDP: Systematic Rateless Coding for Efficient Data Transport in Data Centres (Complete Version)

TL;DR

SCDP is a novel data transport protocol for data centers that efficiently supports one-to-many and many-to-one communication using RaptorQ codes, receiver-driven flow control, and multi-level feedback queuing, outperforming existing protocols.

Contribution

This paper introduces SCDP, a comprehensive data transport protocol that uniquely supports efficient multi-party communication without sacrificing unicast performance, integrating advanced coding and flow control techniques.

Findings

SCDP outperforms NDP and PIAS in multi-party data transport scenarios.

SCDP achieves comparable or better performance than existing protocols for unicast flows.

SCDP eliminates incast and outcast problems in data center networks.

Abstract

In this paper we propose SCDP, a general-purpose data transport protocol for data centres that, in contrast to all other protocols proposed to date, supports efficient one-to-many and many-to-one communication, which is extremely common in modern data centres. SCDP does so without compromising on efficiency for short and long unicast flows. SCDP achieves this by integrating RaptorQ codes with receiver-driven data transport, packet trimming and Multi-Level Feedback Queuing (MLFQ); (1) RaptorQ codes enable efficient one-to-many and many-to-one data transport; (2) on top of RaptorQ codes, receiver-driven flow control, in combination with in-network packet trimming, enable efficient usage of network resources as well as multi-path transport and packet spraying for all transport modes. Incast and Outcast are eliminated; (3) the systematic nature of RaptorQ codes, in combination with MLFQ, enable fast, decoding-free completion of short flows. We extensively evaluate SCDP in a wide range of simulated scenarios with realistic data centre workloads. For one-to-many and many-to-one transport sessions, SCDP performs significantly better compared to NDP and PIAS. For short and long unicast flows, SCDP performs equally well or better compared to NDP and PIAS.