PhD topic: Performance Verification for Virtualized and Cloud Infrastructures

  • How do you verify the performance of your distributed applications?
  • How do you configure your Cloud-based network-server farm to deliver maximum throughput?
  • How do you know you are getting the performance you have paid for from your provider?

The Internet has seen great success mainly due to its decentralised nature and its ability to accommodate myriad services over a simple, packet-switched communication paradigm. However, measurement, monitoring, and management of resources have never been a native part of the Internet architecture that prioritised efficient data delivery over accountability of resource usage.

This has led to a global, complex network that has been notoriously hard to debug, to measure its temporal performance, and to verify that it delivers consistent service quality levels. The lack of such capabilities has so far been swept under the carpet due to the distribution of resources across the global Internet, and the over-provisioning of network bandwidth which has also been the main stream of revenue for network operators.

However, the Internet landscape has been changing drastically over the past few years: the penetration of Cloud computing imposes significant centralisation of compute-network-storage resources over data centre infrastructures that exhibit significant resource contention; and providers’ revenue increasingly depends on their ability to differentiate, and offer predictable and high-performing services over this new environment. The increased collocation of diverse services and users over centralised infrastructures, as well as the many layers of virtualisation (VM, network, application, etc.) required to support such multi-tenancy make the development of always-on measurement and troubleshooting mechanisms a challenging research problem to tackle.

The overarching objective of this PhD project is to design native instrumentation and measurement support for performance verification over virtualised collocation infrastructures. This will enable data centre operators to monitor and troubleshoot their (physical and virtual) infrastructure on-demand, and provide “network measurement as a service” to tenants through exposing appropriate interfaces. Application providers (tenants) will in turn be able to define measurement metrics and instantiate the corresponding modules to verify their applications’ performance, and to validate that their service level agreements with the hosting infrastructure providers are being honoured.

The work will entail experimental research in the areas of Network Function Virtualisation (NFV) and Software-Defined Networking (SDN) with a view towards enabling programmable measurement at the various layers (and locations) of future virtualised infrastructures. For example, it will explore how network nodes can efficiently provide accounting and reporting functionality alongside their main forwarding operation; what support from the end-systems (and virtual machines) will be required in order to synthesise and deploy novel end-to-end performance verification services; and what the specification and execution interfaces of such programmable environment should be.

The research will be conducted as part of the Networked Systems Research Laboratory at the School of Computing Science and the student will be given access to a state-of-the-art virtualisation infrastructure and relevant platforms. Through the strong experimental nature of this project, the student will contribute to a currently buzzing research area, and will be equipped with highly demanded expertise in virtualised systems design, development, and evaluation. Digging under the surface, this work can have transformative effects on the design of future converged ICT environments that will need to deliver high-performance services, and where the boundaries between network, end-system, and application are becoming increasingly blurry.


Competitive scholarships are available for UK/EU students (and a very limited number for students from elsewhere).

Contact Dr Dimitrios Pezaros if you want to discuss the above PhD project further.

Details of how to apply can be found on the Postgraduate research opportunities page.