Resource Discovery Approach to Support a QoS-aware DHT-Based Caching Architecture

Though widely accepted as a key building block for next-generation large scale decentralized systems, the lack of flexibility of DHTs on efficient non identifier-based lookups is a well-known problem. In this paper, a resource discovery service that tackles the issues identified in a decentralized and distributed DHT-based caching architecture for media content distribution is presented. In the proposed approach, complex queries on dynamic peer resources can be performed. This discovery service is layered over an underlying DHT overlay network which connects all the peers, based on the combination of a spanning-tree built bottom-up by mapping DHT peers to their parents, and routing indices which allow peers to efficiently lookup other peers, matching some resource constraints. Measures from simulation as well as from a real implementation are analyzed.