An Experimental Evaluation of the DQ-DHT Algorithm in a Grid Information Service

DQ-DHT is a resource discovery algorithm that combines the Dynamic Querying (DQ) technique used in unstructured peer-to-peer networks with an algorithm for efficient broadcast over a Distributed Hash Table (DHT). Similarly to DQ, DQ-DHT dynamically controls the query propagation on the basis of the desired number of results and the popularity of the resource to be located. Differently from DQ, DQ-DHT exploits the structural properties of a DHT to avoid message duplications, thus reducing the amount of network traffic generated by each query. The goal of this paper is to evaluate experimentally the amount of traffic generated by DQ-DHT compared to the DQ algorithm in a Grid infrastructure. A prototype of a Grid information service, which can use both DQ and DQ-DHT as resource discovery algorithm, has been implemented and deployed on the Grid’5000 infrastructure for evaluation. The experimental results presented in this paper show that DQ-DHT significantly reduces the amount of network traffic generated during the discovery process compared to the original DQ algorithm. Harris Papadakis Foundation for Research and Technology-Hellas, Institute of Computer Science (FORTH-ICS), Heraklion, Greece, e-mail: [email protected] Paolo Trunfio Department of Electronics, Computer Science and Systems (DEIS), University of Calabria, Rende, Italy, e-mail: [email protected] Domenico Talia Institute of High Performance Computing and Networking, Italian National Research Council (ICAR-CNR) and Department of Electronics, Computer Science and Systems (DEIS), University of Calabria, Rende, Italy, e-mail: [email protected] Paraskevi Fragopoulou Foundation for Research and Technology-Hellas, Institute of Computer Science (FORTH-ICS) and Department of Applied Informatics and Multimedia, Technological Educational Institute of Crete, Heraklion, Greece, e-mail: [email protected]