Understanding and characterizing PlanetLab resource usage for federated network testbeds

Global network testbeds are crucial for innovative network research. Built on the success of PlanetLab, the next generation of federated testbeds are under active development, but very little is known about resource usage in the shared infrastructures. In this paper, we conduct an extensive study of the usage profiles in PlanetLab that we collected for six years by running CoMon, a PlanetLab monitoring service. We examine various aspects of node-level behavior as well as experiment-centric behavior, and describe their implications for resource management in the federated testbeds. Our main contributions are threefold: (1) Contrary to common belief, our measurements show there is no tragedy of the commons in PlanetLab, since most PlanetLab experiments exploit the system's network reach more than just its hardware resources; (2) We examine resource allocation systems proposed for the federated testbeds, such as bartering and central banking schemes, and show that they would handle only a small percentage of the total usage in PlanetLab; and (3) Lastly, we identify factors that account for high resource contention or poor utilization in PlanetLab nodes. We analyze workload imbalance and problematic slices in PlanetLab, and describe the implications of our measurements for improving overall utility of the testbed.