Flexible and Scalable Systems for Network Management

Abstract

Our daily lives are heavily reliant upon Internet-connected devices, services, and applications. This reliance makes it more critical than ever that the underlying networks they depend on be reliable, performant, and secure. At the same time, the increasing complexity and diversity of today's devices, services, and applications have made network management tasks more complicated than ever. Modern network management mandates that operators can systematically monitor what is going on in their networks ({\em network monitoring}) and use this information to take real-time preventive or corrective actions ({\em network control}). Achieving these goals while also adhering to the limited compute and storage resources available on modern network devices poses significant challenges.

The contribution of this dissertation is the design and implementation of two systems that enable flexible and scalable network monitoring and control. The network monitoring system, Sonata, collects and analyzes network traffic to infer various network events in real time. The network-control system, SDX, enables fine-grained reactive control actions for interdomain traffic without disrupting the existing routing protocols. For each of these two systems, the dissertation focuses on (i) the abstractions that allow network operators to express flexible programs for both network monitoring and control; (ii) the algorithms that make the best use of limited compute and storage resources; and (iii) the systems that combine the high-level abstractions and the low-level algorithms and can be deployed in production settings.

The lessons learned from this dissertation can help us develop next-generation network-management systems. More concretely, unlike existing systems that rely solely on a single device-type, this dissertation shows that designing systems that can pool resources from a heterogeneous set of devices (targets) is critical for building flexible and scalable network-management systems. It also demonstrates that as the networking technologies and protocols evolve rapidly with time, it is imperative to design modular systems that can swiftly catch up with these changes. Finally, this research also illustrates that it is crucial to select strategic locations (\eg, Internet exchange points) for deployment to drive innovations in Internet-wide traffic monitoring and control.