Use of Devolved Controllers in Data Center Networks

TL;DR

This paper explores the use of multiple decentralized controllers in data center networks to improve scalability, demonstrating how to assign network components to controllers effectively for distributed resource management.

Contribution

It proposes a method for configuring multiple independent controllers to manage network resources efficiently, addressing scalability issues in centralized control systems.

Findings

Devolved controllers can effectively manage network resources in a distributed manner.

A configuration approach ensures each network component is managed by at least one controller.

The approach demonstrates scalability improvements over centralized control.

Abstract

In a data center network, for example, it is quite often to use controllers to manage resources in a centralized man- ner. Centralized control, however, imposes a scalability problem. In this paper, we investigate the use of multiple independent controllers instead of a single omniscient controller to manage resources. Each controller looks after a portion of the network only, but they together cover the whole network. This therefore solves the scalability problem. We use flow allocation as an example to see how this approach can manage the bandwidth use in a distributed manner. The focus is on how to assign components of a network to the controllers so that (1) each controller only need to look after a small part of the network but (2) there is at least one controller that can answer any request. We outline a way to configure the controllers to fulfill these requirements as a proof that the use of devolved controllers is possible. We also discuss several issues related to such implementation.