Searching for Bandwidth-Constrained Clusters

Data-intensive distributed applications can increase their performance by running on a cluster of hosts connected via high-bandwidth interconnections. However, there is no effective method to find such a bandwidth-constrained cluster in a decentralized fashion. Our work is inspired by prior work that treats Internet bandwidth as an approximate tree metric space. This paper presents a decentralized, accurate, and efficient method to find a cluster of Internet hosts, given the desired cluster size and minimum interconnection bandwidth. We describe a centralized polynomial time algorithm for a tree metric space, along with a proof of correctness. We then provide a decentralized version of the algorithm. Simulation experiments with two real-world datasets confirm that our clustering approach achieves high accuracy and scalability. We also discuss the costs of decentralization and how the treeness of the dataset affects clustering accuracy.