Query-load balancing in structured overlays

Query-load (forwarding and answering) balancing in structured overlays is one of the most critical and least studied problems. It has been assumed that caching heuristics can take care of it. We expose that caching, while necessary, is not in itself sufficient. We then provide simple and effective load-aware variants of the standard greedy routing used in overlays, exploiting routing redundancy originally needed for fault-tolerance, to achieve very good query load-balancing.