The Weighted 2-Server Problem

  • Marek Chrobak
  • Jiří Sgall
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1770)


We consider a generalized 2-server problem in which servers have different costs. We prove that, in uniform spaces, a version of the Work Function Algorithm is 5-competitive, and that no better ratio is possible. We also give a 5-competitive randomized, memoryless algorithm for uniform spaces, and a matching lower bound. For arbitrary metric spaces, we prove that no memoryless randomized algorithm has a constant competitive ratio. We study a subproblem in which a request specifies two points to be covered by the servers, and the algorithm decides which server to move to which point; we give a 9-competitive deterministic algorithm for any metric space (no better ratio is possible).


Work Function Competitive Ratio Online Algorithm Deterministic Algorithm Uniform Space 
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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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Marek Chrobak
    • 1
  • Jiří Sgall
    • 2
    • 3
  1. 1.Department of Computer ScienceUniversity of CaliforniaRiverside
  2. 2.Mathematical Inst.AS CRPraha 1Czech Republic
  3. 3.Dept. of Applied Mathematics, Faculty of Mathematics and PhysicsCharles Univ.Praha

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