Design and Application of Intelligent Control Schemes for the Performance Enhancement of a Web Server

作者：Loudini Malik^*; Rezig Sawsen; Hidouci Walid Khaled; Salhi Yahia

来源：Control Engineering and Applied Informatics, 2013, 15(2): 54-66.

• Quality of service
• Web server
• differentiated service
• service delay guarantee
• absolute delay (AD)
• relative delay (RD)
• difference equation (DE)
• fuzzy logic controller
• tabu search

This paper considers the design problem of efficient feedback control schemes to enhance the quality of service (QoS) of a web server (WS) whose input/output dynamic behavior is modeled by discrete mathematical representations. Discrete models allowing the digital simulation of the WS responses to different scenarios of client requests are adopted. The capabilities to guarantee performing service delays, under dynamic workload variations, are the main investigations of this work. To try to provide prospective solutions, advanced feedback control strategies are proposed. First, a fuzzy logic controller (FLC) is implemented as a regulating solution in a closed-loop control architecture. Then, the tabu search (TS) algorithm (TSA) is used to optimize the PLC parameters with innovative tuning procedures. The TS optimized PLC (TSOFLC) is also implemented and applied to attempt to improve the WS QoS. To demonstrate the effectiveness of the adopted closed-loop intelligent control strategies, digital simulation experiments are carried out and examined.

• 出版日期2013-6