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Abstract

Many large-scale distributed systems can benefit from a service that allows them to select among alternative nodes based on their relative network positions. A variety of approache s propose new measurement infrastructures that attempt to sca le this service to large numbers of nodes by reducing the amount of direct measurements to end hosts. In this paper, we introduce a new approach to relative network positioning that eliminates direct probing by leveraging pre-existing infrastructure. Specifically, we exploit the dynamic association of nodes with replica servers from large content distribution networks (CDNs) to dete rmine relative position information – we call this approach CDNbased Relative network Positioning (CRP). We demonstrate how CRP can support two common examples of location information used by distributed applications: server selection and dynamic nodeclustering.AfterdescribingCRPindetail,wepresentresults from an extensive wide-area evaluation that demonstrates its effectiveness.