Experiences building PlanetLab

This paper reports our experiences building PlanetLab over the last four years. It identifies the requirements that shaped PlanetLab, explains the design decisions that resulted from resolving conflicts among these requirements, and reports our experience implementing and supporting the system. Due in large part to the nature of the "PlanetLab experiment," the discussion focuses on synthesis rather than new techniques, balancing system-wide considerations rather than improving performance along a single dimension, and learning from feedback from a live system rather than controlled experiments using synthetic workloads.