Control-theoretic Analysis of Admission Control Mechanisms for Web Server Systems
Author
Summary, in English
Web sites are exposed to high rates of incoming requests. The servers may become overloaded during temporary traffic peaks when more requests arrive than the server is designed for. An admission control mechanism rejects some requests whenever the arriving traffic is too high and thereby maintains an acceptable load in the system. This paper presents how admission control mechanisms can be designed with a combination of queueing theory and control theory. In this paper we model an Apache web server as a GI/G/1-system and then design a PI-controller, commonly used in automatic control, for the server. The controller has been implemented as a module inside the Apache source code. Measurements from the laboratory setup show how robust the implemented controller is, and how it corresponds to the results from the theoretical analysis.
Department/s
Publishing year
2008
Language
English
Pages
93-116
Publication/Series
World Wide Web
Volume
11
Issue
1
Full text
- Available as PDF - 540 kB
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Document type
Journal article
Publisher
Springer
Topic
- Electrical Engineering, Electronic Engineering, Information Engineering
- Control Engineering
Keywords
- queueing theory
- control theory
- system design
- admission control
Status
Published
Project
- Broadband Communications: Modelling and Control of Server Systems
- LCCC
Research group
- Broadband Communication
- LCCC
ISBN/ISSN/Other
- ISSN: 1386-145X