Instrumenting Open vSwitch with Monitoring Capabilities: Designs and Challenges

Recent advances in Software-Defined Networking (SDN) have enabled flexible and programmable network measurement. A promising trend is to conduct network traffic measurement on widely deployed Open vSwitches (OVS) in data centers. However, little attention has been paid to the design options for conducting traffic measurement on the OVS. In this study, we set to explore different design choices and investigate the corresponding trade-offs among resource consumption, measurement accuracy, implementation complexity, and impact on switching speed. For this purpose, we empirically design and implement four different measurement schemes in OVS, by either closely integrating forwarding and measurement functions into a pipeline, or decoupling them into parallel operations. Through extensive experiments and comparisons, we quantitatively show the various trade-offs that the different schemes strike to balance, and demonstrate the feasibility of instrumenting OVS with monitoring capabilities. These results provide valuable insights into which design will best serve various measurement and monitoring needs.