Testing tool of SDN controllers’ performance

Abstract

The SDN controllers with the network applications running on the top of them, can be seen as ”network brains”. Those applications apply the control logic and they will install some commands in the data plane. We can see that the performance of those applications is really important for a SDN controller and therefore, for the network it manages. Because of this importance, the purpose of this thesis is to adapt OFCProbe (one existing evaluation tool) in order to assess the performance of some processes on the applications running on the top of the SDN controller. Our new tool, denoted as CPBeT, is aimed at changing the network topology in real-time, in order to load the algorithm which calculates the shortest path on the controller. CPBeT will generate a specific amount of OpenFlow control traffic through the network and it will force the controller to process large amount of packets. CPBeT will build a virtual network with virtual switches and hosts, and we will have the control over the topology, number of hosts, generation of packets, etc. The experimental part of this work will evaluate the behaviour of L2 network application that run on the top of a Floodlight controller with a time varying topology which is the worst case for the shortest path algorithm. We will analyze the CPU and RAM usage on the controller changing some parameters of the experiments, like hosts, topology or rate of change of the topology, and we will demonstrate the effect of the computation of the shortest path algorithm on the controllers and how many devices the controller can manage before its saturation. Once the controller is saturated, we will analyze its behaviour and the reasons that cause that saturation.