liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Robust Quality Management for Differentiated Imprecise Data Services
Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
Linköping University, Department of Computer and Information Science, RTSLAB - Real-Time Systems Laboratory. Linköping University, The Institute of Technology.
Linköping University, Department of Computer and Information Science, RTSLAB - Real-Time Systems Laboratory. Linköping University, The Institute of Technology.
University of Virginia, Charlottesville, USA.
2004 (English)In: Proceedings of the 25th IEEE International Real-Time Systems Symposium, 2004, 265-275 p.Conference paper, Published paper (Refereed)
Abstract [en]

Several applications, such as Web services and e-commerce, are operating in open environments where the workload characteristics, such as the load applied on the system and the worst-case execution times, are inaccurate or even not known in advance. This implies that transactions submitted to a real-time database cannot be subject to exact schedulability analysis given the lack of a priori knowledge of the workload. In this paper we propose an approach, based on feedback control, for managing the quality of service of real-time databases that provide imprecise and differentiated services, given inaccurate workload characteristics. For each service class, the database operator specifies the quality of service requirements by explicitly declaring the precision requirements of the data and the results of the transactions. The performance evaluation shows that our approach provides reliable quality of service even in the face of varying load and inaccurate execution time estimates.

Place, publisher, year, edition, pages
2004. 265-275 p.
Keyword [en]
Real-time systems, Real-time databases, Control theory, Realtidssystem, Realtidsdatabaser, Reglerteknik, CUGS
National Category
Control Engineering
Identifiers
URN: urn:nbn:se:liu:diva-12637DOI: 10.1109/REAL.2004.49ISBN: 0-7695-2247-5 (print)OAI: oai:DiVA.org:liu-12637DiVA: diva2:16750
Conference
25th IEEE International Real-Time Systems Symposium, Lisbon, Portugal, December 5-8, 2004
Available from: 2007-10-17 Created: 2007-10-17 Last updated: 2013-07-04
In thesis
1. QoS Control of Real-Time Data Services under Uncertain Workload
Open this publication in new window or tab >>QoS Control of Real-Time Data Services under Uncertain Workload
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Real-time systems comprise computers that must generate correct results in a timely manner. This involves a wide spectrum of computing systems found in our everyday life ranging from computers in rockets to our mobile phones. The criticality of producing timely results defines the different types of realtime systems. On one hand, we have the so-called hard real-time systems, where failing to meet deadlines may result in a catastrophe. In this thesis we are, however, concerned with firm and soft real-time systems, where missing deadlines is acceptable at the expense of degraded system performance. The usage of firm and soft real-time systems has increased rapidly during the last years, mainly due to the advent of applications in multimedia, telecommunication, and e-commerce. These systems are typically data-intensive, with the data normally spanning from low-level control data, typically acquired from sensors, to high-level management and business data. In contrast to hard real-time systems, the environments in which firm and soft real-time systems operate in are typically open and highly unpredictable. For example, the workload applied on a web server or base station in telecommunication systems varies according to the needs of the users, which is hard to foresee. In this thesis we are concerned with quality of service (QoS) management of data services for firm and soft real-time systems. The approaches and solutions presented aim at providing a general understanding of how the QoS can be guaranteed according to a given specification, even if the workload varies unpredictably. The QoS specification determines the desired QoS during normal system operation, and the worst-case system performance and convergence rate toward the desired setting in the face of transient overloads. Feedback control theory is used to control QoS since little is known about the workload applied on the system. Using feedback control the difference between the measured QoS and the desired QoS is formed and fed into a controller, which computes a change to the operation of the real-time system. Experimental evaluation shows that using feedback control is highly effective in managing QoS such that a given QoS specification is satisfied. This is a key step toward automatic management of intricate systems providing real-time data services.

Place, publisher, year, edition, pages
Institutionen för datavetenskap, 2007. 244 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1143
Keyword
real-time system, database, feedback control
National Category
Computer Science
Identifiers
urn:nbn:se:liu:diva-10016 (URN)978-91-85895-49-6 (ISBN)
Public defence
2007-11-15, Planck, Fysikhuset, Linköpings universitet, 13:15 (English)
Opponent
Supervisors
Available from: 2007-10-17 Created: 2007-10-17 Last updated: 2009-04-22

Open Access in DiVA

No full text

Other links

Publisher's full textLink to Ph.D. thesis

Authority records BETA

Gunnarsson, SvanteAmirijoo, MehdiHansson, Jörgen

Search in DiVA

By author/editor
Gunnarsson, SvanteAmirijoo, MehdiHansson, Jörgen
By organisation
Automatic ControlThe Institute of TechnologyRTSLAB - Real-Time Systems Laboratory
Control Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 189 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf