Structured overlay network for file distribution

Abstract

The file distribution from a source node to n sink nodes along a structured overlay network can be done in time Θ(log n). In this paper, we model the problem of finding an optimal overlay network for file distribution as a combinatorial optimization problem, i.e., finding a weighted spanning tree which connects the source node and sink nodes and has the minimum file distribution time. We use an edge-based file distribution protocol, in which after a node receives a file it then transfers the file to its neighbor nodes one after another in a sequential order. We give the formulation of file distribution time, and use it as the objective function. The corresponding combinatorial optimization problem is NP-hard in general. We present a heuristic algorithm which derives an overlay network with file distribution time Θ(log n) and show that the derived overlay network is optimal if the file transfer delays between all pairs of nodes are the same. © 2010 Springer-Verlag.