Title: Enhancing web server relative delay services by an integrated SA-fuzzy logic controller

Authors: Malik Loudini; Sawsen Rezig

Addresses: Ecole Nationale Supérieure d'Informatique (ESI), Laboratoire de Communication dans les Systèmes Informatiques (LCSI), BP 68M, 16270 Oued Smar, El Harrach, Algiers, Algeria ' Ecole Nationale Supérieure d'Informatique (ESI), Laboratoire de Communication dans les Systèmes Informatiques (LCSI), BP 68M, 16270 Oued Smar, El Harrach, Algiers, Algeria

Abstract: This article addresses an investigation of the capabilities of intelligent feedback control methodologies to provide satisfactory web server quality of service (QoS) in terms of delay services. Fuzzy logic-based control architectures are proposed to enhance the system performances. The first closed-loop control scheme to be applied is the standard proportional integral (PI) type Mamdani's fuzzy logic controller (FLC). Then, the simulated annealing (SA) algorithm (SAA) is used to optimise the FLC parameters with innovative tuning procedures. Both of the FLC and the SA optimised FLC (SAOFLC) are implemented and tested to attempt to improve the QoS of a web server faced to sudden variations of workload. The performances of the adopted closed-loop intelligent control strategies are examined via simulation experiments.

Keywords: web servers; quality of service; QoS; service differentiation; DiffServ; service delay guarantee; relative delay; feedback control; fuzzy logic controllers; FLC; fuzzy control; simulated annealing; intelligent control.

DOI: 10.1504/IJWET.2013.052583

International Journal of Web Engineering and Technology, 2013 Vol.8 No.1, pp.27 - 57

Published online: 31 Mar 2014 *

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