Admission control of the Apache web server
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 G/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 correspond to
the results from the theoretical analysis.
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 G/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 correspond to
the results from the theoretical analysis.
Publishing year
2004
Language
English
Publication/Series
Seventeenth Nordic Teletraffic Seminar, NTS 17, Fornebu, Norway, 25-27 August 2004
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Document type
Conference paper
Publisher
Fornebu : Telenor
Topic
- Communication Systems
- Control Engineering
Status
Published
ISBN/ISSN/Other
- ISBN: 82-423-0595-1