Flexspander: augmenting expander networks in high-performance systems with optical bandwidth steering

Abstract

Communication efficiency is one of the deciding factors in determining many of today’s high-performance computing (HPC) applications. Traditionally, HPC systems have been on static network topologies, making them inflexible to the variety of skewed traffic demands that may arise due to the spatial locality inherent in many applications. To handle traffic locality, researchers have proposed integrating optical circuit switches (OCSs) into the network architecture, which reconfigures the network topology to alter and dynamically adapt to the predicted traffic. In this paper, we present a novel reconfigurable network topology called Flexspander. Beyond offering a flexible interconnect, Flexspander also offers full flexibility in terms of construction and can be built with any arbitrary combination of commercial electrical packet switches and OCSs. We evaluate Flexspander performance through extensive simulations with multiple network traces, and our results show improved performance for Flexspander over currently proposed static and reconfigurable topologies in terms of the flow completion time.

ReNets: Statically-Optimal Demand-Aware Networks

“…The advent of technologies for reconfigurable (a.k.a. malleable [18]) networks recently introduced a new degree of freedom to the datacenter network design problem [1,7,10,11,13,15,16,17,18,45,46,47,48,49,50,51,52,53,54]. By relying on movable antennas [51], mirrors [13,50], and "disco-balls" [1], novel technologies in the context of optical circuit switches [10,11,12,49], 60 GHz wireless communication [50,55], free-space optics [1,13], provide unprecedented topological flexibilities, allowing to quickly adapt the topology to traffic demands.…”

“…On the contrary, self-adjusting DANs do not require such knowledge and can additionally exploit temporal locality, by adapting the topology to the demand in an online manner. The vision of such self-adjusting networks is enabled by emerging optical technologies which allow us to quickly reconfigure the topology over time [1,10,11,12,13,14,15,16,17].…”

PINE: Photonic Integrated Networked Energy efficient datacenters (ENLITENED Program) [Invited]

“…Building on these successful results, phase 2 efforts will address the benefits of advanced reconfigurable network design [20], of multi-workload defragmentation, and a finer grained temporal reconfiguration. Different physical connectivity schemes between electronic and SiP optical switches will be Research Article considered and evaluated in the PINE system testbed.…”

Reconfigurable Optical Datacom Networks by Self-supervised Learning

“…workloads, etc.). Thanks to recent advances in scalable and manufacturable silicon-photonic technologies [12], flat and disruptive optical interconnect architectures scaling up to tens of thousands of terminals by enabling direct (thus, low-diameter) wavelength switching between racks [3,12,15] have been recognized as promising solutions for meeting the above challenges.…”

“…Therefore, effective reconfiguration schemes are essential to fully exploit the benefits of optical interconnects and ensure consistent system performance [4,17]. The authors in [15] proposed a hybrid optical/electrical switching-based reconfigurable network topology leveraging heuristic algorithms for determining the wiring and bandwidth steering schemes for different traffic profiles. In [16], the authors leveraged a deep learning approach to learn the mapping between the traffic distribution and the optimal topology configuration.…”