Recent research [7,12,2] has shown that Internet hosts can be efficiently (i.e., without excessive measurements) mapped to
a virtual (Euclidean) coordinate system, where the geometric distance between any two nodes in this virtual space approximates
their real IP network distance (latency). Based on this result, in this paper, we propose an alternative approach that inherently incorporates a virtual coordinate system into a P2P network. In our system, called Leopard, a node is assigned a coordinate
in the so-called node geo space as it joins the network, and obtains neighbor relationships that reflects network proximity from the beginning. The object
id space and the node geo space are then “weaved” together via a novel technique called geographically-scoped hashing. Through analysis and simulation, we show three major desirable properties of Leopard to exemplify the power of this paradigm
shift: i) a constant routing stretch, i.e., IP level network latency of object look-up is proportional to the distance between
a requesting node and the target object; ii) always locates a near-by copy when multiple copies exist; and iii) effectively
handles “flash crowd” traffic with near optimal load balancing.
Keywords peer-to-peer - lookup service - virtual coordinates - locality-awareness
This work was supported in part by NSF grant ITR-0085824 and CNS-0435444.