A Range Query Model Based on DHT in P2P System

Abstract

A Peer-to-Peer (P2P) system has emerged as one of the most successful ways to share resources in distributed environment, and DHT(Distributed Hash Table) is used as an effective approach to locate shared resources in a P2P system. This paper describes an extended DHT model by combining DHT with B+ tree. The sharing resources are represented by their attributes. Each query request is associated with ranges in one or more attributes, and B+ tree is introduced to organize the values of each attribute. In order to implement and verify our model, Chord is chosen as the underlying DHT system. In addition to equality queries, this model also makes it possible to execute range queries over a DHT. The relevant technologies mapping from B+ trees to Chord system are described. The node adding and leaving process and range query process are illustrated.