Uniform service systems with k servers

  • Esteban Feuerstein
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1380)


We consider the problem of k servers situated on a uniform metric space that must serve a sequence of requests, where each request consists of a set of locations of the metric space and can be served by moving a server to any of the nodes of the set. The goal is to minimize the total distance traveled by the servers. This problem generalizes a problem presented by Chrobak and Larmore in [7]. We give lower and upper bounds on the competitive ratio achievable by on-line algorithms for this problem, and consider also interesting particular cases.


Competitive Ratio Online Algorithm Vertex Cover Total Completion Time Competitive Algorithm 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    H. Alborzi, E. Torng, P. Uthaisombut, and S. Wagner. The k-client problem. In Proc. of Eigth Annual ACM-SIAM Symposium on Discrete Algorithms (SODA), 1995.Google Scholar
  2. 2.
    G. Ausiello, E. Feuerstein, S. Leonardi, L. Stougie, and M. Talamo. Competitive algorithms for the traveling salesman. In Proc. of Workshop on Algorithms and Data Structures (WADS'95), Springer-Verlag, 1995.Google Scholar
  3. 3.
    G. Ausiello, E. Feuerstein, S. Leonardi, L. Stougie, and M. Talamo. Serving requests with on-line routing. In Proc. of 4th Scandinavian Workshop on Algorithm Theory (SWAT'94), pages 37–48, Springer-Verlag, July 1995.Google Scholar
  4. 4.
    S. Ben-David, A. Borodin, R. Karp, G. Tardos, and A. Widgerson. On the power of randomization in on-line algorithms. Algorithmica, 11:2–14, 1994.MathSciNetCrossRefGoogle Scholar
  5. 5.
    A. Borodin, Sandy Irani, P. Raghavan, and B. Schieber. Competitive paging with locality of reference. In Proc. of 23rd ACM Symposium on Theory of Computing, pages 249–259, 1991.Google Scholar
  6. 6.
    A. Borodin, N. Linial, and M. Saks. An optimal online algorithm for metrical task system. Journal of the Association for Computing Machinery, 39(4):745–763, 1992.MathSciNetGoogle Scholar
  7. 7.
    M. Chrobak and L. Larmore. The server problem and on-line games. In On-line Algorithms, pages 11–64, AMS-ACM, 1992.Google Scholar
  8. 8.
    E. Feuerstein. Paging more than one page. In Proceedings of the Second Latin American Symposium on Theoretical Informatics (LATIN95), pages 272–287, Springer-Verlag, 1995. An improved version of this paper will appeax in Theoretical Computer Science (1997).Google Scholar
  9. 9.
    E. Feuerstein and A. Strejilevich de Loma. On multi-threaded paging. In Proceedings of the 7th International Symposium on Algorithms and Computation (ISAAC'96), Springer-Verlag, 1996.Google Scholar
  10. 10.
    M. R. Garey and D. S. Johnson. Computers and Intractabiliy — A Guide to the Theory of NP-completeness. W.H. Freeman and Company, San Francisco, 1979.Google Scholar
  11. 11.
    A. Karlin, M. Manasse, L. Rudolph, and D. Sleator. Competitive snoopy caching. Algorithmica, 3():79–119, 1988.MathSciNetCrossRefGoogle Scholar
  12. 12.
    M.S. Manasse, L.A. McGeoch, and D.D. Sleator. Competitive algorithms for server problems. Journal of Algorithms, 11(2):208–230, 1990.MathSciNetCrossRefGoogle Scholar
  13. 13.
    R. Motwani. Lecture Notes on Approximation Algorithms. Technical Report, Stanford University.Google Scholar
  14. 14.
    P. Raghavan and M. Snir. Memory versus randomization in on-line algorithms. RC 15622, IBM, 1990.Google Scholar
  15. 15.
    D.D. Sleator and R.E. Tarjan. Amortized efficiency of list update and paging rules. Communications of ACM, 28(2):202–208, 1985.MathSciNetCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Esteban Feuerstein
    • 1
    • 2
  1. 1.Dpto. de Computatión, FCEyNUniversidad de Buenos Aires Institute de CienciasArgentina
  2. 2.Universidad de General SarmientoArgentina

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