Self-* overload control for distributed web systems

Novella Bartolini, Giancarlo Bongiovanni, Simone Silvestri

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


Unexpected increases in demand and most of all flash crowds are considered the bane of every web application as they may cause intolerable delays or even service unavailability. Proper quality of service policies must guarantee rapid reactivity and responsiveness even in such critical situations. Previous solutions fail to meet common performance requirements when the system has to face sudden and unpredictable surges of traffic. Indeed they often rely on a proper setting of key parameters which requires laborious manual tuning, preventing a fast adaptation of the control policies. We contribute an original Self-* Overload Control (SOC) policy. This allows the system to self-configure a dynamic constraint on the rate of admitted sessions in order to respect service level agreements and maximize the resource utilization at the same time. Our policy does not require any prior information on the incoming traffic or manual configuration of key parameters. We ran extensive simulations under a wide range of operating conditions, showing that SOC rapidly adapts to time varying traffic and self-optimizes the resource utilization. It admits as many new sessions as possible in observance of the agreements, even under intense workload variations. We compared our algorithm to previously proposed approaches highlighting a more stable behavior and a better performance.

Original languageEnglish (US)
Title of host publication2008 16th International Workshop on Quality of Service, IWQoS
Number of pages10
StatePublished - 2008
Event2008 16th International Workshop on Quality of Service, IWQoS - Enschede, Netherlands
Duration: Jun 2 2008Jun 4 2008

Publication series

NameIEEE International Workshop on Quality of Service, IWQoS
ISSN (Print)1548-615X


Other2008 16th International Workshop on Quality of Service, IWQoS

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering


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