Network Topologies for Composable Data Centers

Abstract

Suitable composable data center networks (DCNs) are essential to support the disaggregation of compute components in highly efficient next generation data centers (DCs). However, designing such composable DCNs can be challenging. A composable DCN that adopts a full mesh backplane between disaggregated compute components within a rack and employs dedicated interfaces on each point-to-point link is wasteful and expensive. In this paper, we propose and describe two (i.e., electrical, and electricaloptical) variants of a network for composable DC (NetCoD). NetCoD adopts a targeted design to reduce the number of transceivers required when a mesh physical backplane is deployed between disaggregated compute components in the same rack. The targeted design leverages optical communication techniques and components to achieve this with minimal or no network performance degradation. We formulate a MILP model to evaluate the performance of both variants of NetCoD in rack-scale composable DCs that implement different forms of disaggregation. The electrical-optical variant of NetCoD achieves similar performance as a reference network while utilizing fewer transceivers per compute node. The targeted adoption of optical technologies by both variants of NetCoD achieves greater (4 -5 times greater) utilization of available network throughput than the reference network which implements a generic design. Under the various forms of disaggregation considered, both variant of NetCoD achieve near-optimal compute energy efficiency in the composable DC while satisfying both compute and network constraints. This is because marginal concession of optimal compute energy efficiency is often required to achieve overall optimal energy efficiency in composable DCs. INDEX TERMSComposable data centers, disaggregated data centers, energy efficient networks, data center networks, MILP, optical communication, wavelength division multiplexing, optical routing networks, silicon photonic.

Disaggregation for Energy Efficient Fog in Future 6G Networks

“…In contrast to [13] where the authors focused on the design of an energy efficient network for DCs with disaggregated servers, we do not consider DC networks in this paper to simplify our evaluation scenario. Moreover, in previous works [30], [42], we formulated a MILP model that placed workloads energy efficiently in composable DC networks. Therefore, this paper focuses on the application of the resource disaggregation concept in the fog computing layer of the cloud of things architecture.…”

On the Complexity of Configuration and Orchestration for Enabling Disaggregated Server Provisioning in Optical Composable Data Centres

“…Some of the works have focused solely on the design and evaluation of flexible network fabrics to be exploited within CDC infrastructures (e.g., [6]) while others also focused on their integration with the hardware blades and the performance of the full system. As a result, several optical network designs have been proposed (e.g., [1,2]), with some works advocating for the use of hybrid networks combining electrical and optical switching technologies (e.g., [8]).…”

“…The other case of study is the NetCoD architecture presented in [8]. As in the DACON architecture, the CDC resources are organized in heterogeneous racks hosting all types of computational resources.…”

On the challenges of optical disaggregated data center networking for ML/AI applications

“…These impairments are especially notorious when dealing with the allocation of ML applications, since their accentuated time-varying behavior and their highly demanding resource profile pushes the limits of what traditional server units are capable of. In light of these limitations, the resource disaggregation paradigm has been proposed [6], [7]. It consists on separating the computational resources of server units in completely independent hardware blades, which then are hosted at rack scale.…”