Title: A monitoring service for large-scale dynamic query optimisation in a grid environment

Authors: Mahmoud El Samad, Julien Gossa, Franck Morvan, Abdelkader Hameurlain, Jean-Marc Pierson, Lionel Brunie

Addresses: Institute of Research in Computer Science of Toulouse (IRIT), Paul Sabatier University (UPS), Toulouse, UMR5505, France. ' Laboratory of Computer Science in Image and Information Systems (LIRIS), National Institute of Applied Science (INSA) of Lyon, UMR5205, France. ' Institute of Research in Computer Science of Toulouse (IRIT), Paul Sabatier University (UPS), Toulouse, UMR5505, France. ' Institute of Research in Computer Science of Toulouse (IRIT), Paul Sabatier University (UPS), Toulouse, UMR5505, France. ' Institute of Research in Computer Science of Toulouse (IRIT), Paul Sabatier University (UPS), Toulouse, UMR5505, France. ' Laboratory of Computer Science in Image and Information Systems (LIRIS), National Institute of Applied Science (INSA) of Lyon, UMR5205, France

Abstract: The execution plans generated by the traditional optimisers for large-scale distributed queries in a grid can be suboptimal for the following reasons: the centralisation of decisions made by the optimiser; the inaccuracy of estimations; the unavailability of up-to-date description of resources. In this paper, we propose an approach to improve the estimation of the execution cost of a query (or part of a query) in a grid environment by using Mobile Agents (MAs) and runtime monitoring information. First, Mas allow dynamic optimisation in a decentralised and autonomous way. Second, the retrieval of the monitoring information causes some issues addressed by a dedicated service called the Network Distance Service (NDS). The performance evaluation shows that our approach allows a better estimation of the execution cost of a query in a grid and a large benefit to monitor the CPU for a mobile join when the subestimation errors increase while the benefit to monitor the bandwidth is poor.

Keywords: query optimisation; mobile agents; MAS; multi-agent systems; agent-based systems; monitoring services; grid computing; runtime monitoring.

DOI: 10.1504/IJWGS.2008.018889

International Journal of Web and Grid Services, 2008 Vol.4 No.2, pp.222 - 246

Available online: 21 Jun 2008 *

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