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An optimal trade-off between content freshness and refresh cost

Part of: Special processes

Published online by Cambridge University Press:  14 July 2016

Yibei Ling  and
Jie Mi
Yibei Ling*
Affiliation:
Telcordia Technologies
Jie Mi*
Affiliation:
Florida International University
*
∗ Postal address: Applied Research, Telcordia Technologies, RRC-1A204, One Telcordia Drive, Piscataway, NJ 08854-4157, USA. Email address: lingy@research.telcordia.com
∗∗ Postal address: Department of Statistics, Florida International University, Miami, FL 33199, USA. Email address: mi@fiu.edu
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Abstract

Caching is an effective mechanism for reducing bandwidth usage and alleviating server load. However, the use of caching entails a compromise between content freshness and refresh cost. Constant refreshing allows a high degree of content freshness at a greater cost of system resource. Conversely, too little refreshing reduces content freshness but saves the cost of resource usage. To address the freshness-cost problem, we formulate the refresh scheduling problem with a generic cost model and use this cost model to determine an optimal refresh frequency that gives the best trade-off between refresh cost and content freshness. We prove the existence and uniqueness of an optimal refresh frequency under the assumptions that the arrival of updated content is Poisson and the age-related cost monotonically increases with decreasing freshness. In addition, we provide an analytic comparison of system performance under fixed refresh scheduling and random refresh scheduling, showing that two refresh schedulings with the same average refresh frequency are mathematically equivalent in terms of the long-run average cost.

Keywords

Cachingcontent freshnessrefresh costoptimal refresh frequencyPoisson process

MSC classification

Primary: 60K05: Renewal theory
Secondary: 60K10: Applications (reliability, demand theory, etc.)
Type
Research Papers
Information
Journal of Applied Probability , Volume 41 , Issue 3 , September 2004 , pp. 721 - 734
Copyright
Copyright © Applied Probability Trust 2004 

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References

Cho, J., and Garcia-Molina, H. (2000). Synchronizing a database to improve freshness. In Proc. 2000 ACM SIGMOD Internat. Conf. Management of Data (May 2000, Dallas, TX), eds Chen, W., Naughton, J. F. and Bernstein, P. A., ACM Press, New York, pp. 117–128. Available at http://www.acm.org/sigmod/.10.1145/342009.335391Google Scholar
Cho, J., and Garcia-Molina, H. (2000). The evolution of the web and implications for an incremental crawler. In Proc. 26th Internat. Conf. Very Large Databases (September 2000, Cairo), eds El Abbadi, A. et al., Morgan Kaufmann, San Francisco, pp. 200–209. Available at http://www.informatik.uni-trier.de/∼ley/db/conf/vldb/.Google Scholar
Cohen, E., and Kaplan, H. (2001). Age penalty and its effects on cache performance. In Proc. 3rd USENIX Symp. Internet Technol. Systems (March 2001, San Francisco, CA), pp. 73–84.Google Scholar
Cohen, E., and Kaplan, H. (2001). Refreshment policies for web content caches. In Proc. IEEE INFOCOM 2001 (April 2001, Anchorage, AK), Vol. 3, pp. 1398–1406. Available at http://www.ieee-infocom.org/2001/.Google Scholar
Duska, B. M., Marwood, D., and Feeley, M. J. (1997). The measured access characteristics of world-wide-web client proxy caches. In Proc. USENIX Symp. Internet Technol. Systems (December 1997, Monterey, CA), pp. 23–36. Available at http://www.usenix.org/publications/library/proceedings/usits97/.Google Scholar
Lee, K.-W., Amiri, K., Sahu, S., and Venkatramani, C. (2002). On the sensitivity of cooperative caching performance to workload and network characteristics. In Proc. ACM SIGMETRICS 2002 (June 2002, Marina Del Rey, CA), ACM Press, New York, pp. 268–269. Available at http://doi.acm.org/10.1145/511334.511374/.Google Scholar
Notess, G. (2001). On the net: freshness issue and complexities with web search engines. OnLine 25, No. 6. Available at http://www.infotoday.com/online/.Google Scholar
Ross, S. M. (1996). Stochastic Processes. John Wiley, New York.Google Scholar
Wessels, D. (2001). Web Caching. O'Reilly, Sebastopol, CA.Google Scholar