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On the Separation and Equivalence of Paging Strategies and Other Online Algorithms

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Abstract

We introduce a new technique for the analysis of online algorithms, namely bijective analysis, that is based on pair-wise comparison of the costs incurred by the algorithms. Under this framework, an algorithm A is no worse than an algorithm B if there is a bijection \(\pi \) defined over all request sequences of a given size such that the cost of A on \(\sigma \) is no more than the cost of B on \(B(\pi (\sigma ))\). We also study a relaxation of bijective analysis, termed average analysis, in which we compare two algorithms based on their corresponding average costs over request sequences of a given size. We apply these new techniques in the context of two fundamental online problems, namely paging and list update. For paging, we show that any two lazy online algorithms are equivalent under bijective analysis. This result demonstrates that, without further assumptions on characteristics of request sequences, it is unlikely, or even undesirable, to separate online paging algorithms based on their performance. However, once we restrict the set of request sequences to those exhibiting locality of reference, and in particular using a model of locality due to Albers et al. (J Comput Syst Sci 70(2):145–175, 2005), we demonstrate that Least-Recently-Used (LRU) is the unique optimal strategy according to average analysis. This is, to our knowledge, the first deterministic model to provide full theoretical backing to the empirical observation that LRU is preferable in practice. Concerning list update, we obtain similar conclusions, in terms of the bijective comparison of any two online algorithms, and in terms of the superiority (albeit not necessarily unique) of the Move-To-Front (MTF) heuristic in the presence of locality of reference.

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Notes

  1. For an extension of average analysis to problems in which the input contains elements with real-valued weights, see [24]

  2. This is one of the reasons that Albers et al. [3] use the fault rate, instead of overall cost, as a performance measure.

  3. Note that in the context of concave analysis, each continuation must naturally belong in the set \({\mathcal {I}}_h^f\).

  4. We can assume that \(f(2)=2\) since otherwise we are restricted to sequences that contain only one item.

References

  1. Albers, S.: On the influence of lookahead in competitive paging algorithms. Algorithmica 18(3), 283–305 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  2. Albers, S.: Improved randomized on-line algorithms for the list update problem. SIAM J. Comput. 27(3), 682–693 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  3. Albers, S., Favrholdt, L.M., Giel, O.: On paging with locality of reference. J. Comput. Syst. Sci. 70(2), 145–175 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  4. Albers, S., Lauer, S.: On list update with locality of reference. J. Comput. Syst. Sci. 82(5), 627–653 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  5. Albers, S., Mitzenmacher, M.: Average case analyses of list update algorithms, with applications to data compression. Algorithmica 21(3), 312–329 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  6. Albers, S., von Stengel, B., Werchner, R.: A combined bit and timestamp algorithm for the list update problem. Inf. Proces. Lett. 56, 135–139 (1995)

    Article  MATH  Google Scholar 

  7. Albers, S., Westbrook, J.: Self-organizing data structures. In: Online Algorithms: The State of the Art. Lecture Notes in Computer Science 1442, pp. 13–51. Springer (1998)

  8. Ambühl, C., Gärtner, B., von Stengel, B.: Optimal lower bounds for projective list update algorithms. ACM Trans. Algorithms 9(4), 31 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  9. Angelopoulos. S.: Parameterized analysis of online Steiner tree problems. In: Adaptive, Output Sensitive, Online and Parameterized Algorithms, number 09171 in Dagstuhl Seminar Proceedings. Schloss Dagstuhl–Leibniz-Zentrum fuer Informatik, Germany (2009)

  10. Angelopoulos, S., Dorrigiv, R., López-Ortiz, A.: List update with locality of reference. In: Proceedings of the 8th Latin American Symposium on Theoretical Informatics, pp. 399–410 (2008)

  11. Angelopoulos, S., Renault, M., Schweitzer, P.: Stochastic dominance and the bijective ratio of online algorithms (2016). arXiv:1607.06132

  12. Angelopoulos, S., Schweitzer, P.: Paging and list update under bijective analysis. J. ACM 60(2), 7 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  13. Bachrach, R., El-Yaniv, R., Reinstädler, M.: On the competitive theory and practice of online list accessing algorithms. Algorithmica 32(2), 201–245 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  14. Becchetti, L.: Modeling locality: A probabilistic analysis of LRU and FWF. In: Proceedings of the 12th Annual European Symposium on Algorithms (ESA ’04), volume 3221 of Lecture Notes in Computer Science, pp. 98–109 (2004)

  15. Ben-David, S., Borodin, A.: A new measure for the study of on-line algorithms. Algorithmica 11, 73–91 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  16. Borodin, A., El-Yaniv, R.: Online Computation and Competitive Analysis. Cambridge University Press, Cambridge (1998)

    MATH  Google Scholar 

  17. Borodin, A., Irani, S., Raghavan, P., Schieber, B.: Competitive paging with locality of reference. J. Comput. Syst. Sci. 50, 244–258 (1995)

    Article  MathSciNet  MATH  Google Scholar 

  18. Boyar, J., Ehmsen, M.R., Kohrt, J.S., Larsen, K.S.: A theoretical comparison of LRU and LRU-k. Acta Inf. 47(7–8), 359–374 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  19. Boyar, J., Favrholdt, L.M.: The relative worst order ratio for on-line algorithms. Trans. Algorithms 3(2), 22 (2007)

    MATH  Google Scholar 

  20. Boyar, J., Favrholdt, L.M., Larsen, K.S.: The relative worst order ratio applied to paging. J. Comput. Syst. Sci. 73(5), 818–843 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  21. Boyar, J., Gupta, S., Larsen, K.S.: Access graph results for LRU versus FIFO under relative worst order analysis. In: Proceedings of the 13th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT), pp. 328–339 (2012)

  22. Boyar, J., Gupta, S., Larsen, K.S.: Relative interval analysis of paging algorithms on access graphs. Theor. Comput. Sci. 568, 28–48 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  23. Boyar, J., Irani, S., Larsen, K.S.: A comparison of performance measures for online algorithms. Algorithmica 72(4), 969–994 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  24. Boyar, J., Larsen, K.S., Maiti, A.: A comparison of performance measures via online search. Theor. Comput. Sci. 532, 2–13 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  25. Boyar, J., Medvedev, P.: The relative worst order ratio applied to seat reservation. ACM Trans. Algorithms 4(4), 48 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  26. Burley, W.R., Irani, S.: On algorithm design for metrical task systems. Algorithmica 18(4), 461–485 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  27. Burrows, M., Wheeler, D.J.: A block-sorting lossless data compression algorithm. Technical Report 124, DEC SRC (1994)

  28. Chrobak, M., Noga, J.: LRU is better than FIFO. Algorithmica 23(2), 180–185 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  29. Denning, P.J.: The working set model for program behaviour. Commun. ACM 11(5), 323–333 (1968)

    Article  MathSciNet  MATH  Google Scholar 

  30. Dorrigiv, R., López-Ortiz, Alejandro A., Munro, J.I.: On the relative dominance of paging algorithms. Theor. Comput. Sci. 410(38–40), 3694–3701 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  31. Dorrigiv, R., López-Ortiz, A.: A survey of performance measures for on-line algorithms. SIGACT News (ACM Special Interest Group on Automata and Computability Theory) 36(3), 67–81 (2005)

    Google Scholar 

  32. Dorrigiv, R., López-Ortiz, A.: List update with probabilistic locality of reference. Inf. Process. Lett. 112(13), 540–543 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  33. El-Yaniv, R.: There are infinitely many competitive-optimal online list accessing algorithms. Discussion paper, Hebrew University of Jerusalem, Center for Rationality and Interactive Decision Theory (1996)

  34. Hester, J.H., Hirschberg, D.S.: Self-organizing linear search. ACM Comput. Surv. 17(3), 295 (1985)

    Article  Google Scholar 

  35. Irani, S.: Two results on the list update problem. Inf. Process. Lett. 38, 301–306 (1991)

    Article  MathSciNet  MATH  Google Scholar 

  36. Irani, S., Karlin, A.R., Phillips, S.: Strongly competitive algorithms for paging with locality of reference. SIAM J. Comput. 25, 477–497 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  37. Kamali, S., López-Ortiz, A.: A survey of algorithms and models for list update. In: Space-Efficient Data Structures, Streams, and Algorithms - Papers in Honor of J. Ian Munro on the Occasion of His 66th Birthday, pp. 251–266 (2013)

  38. Kaplan, H., Landau, S., Verbin, E.: A simpler analysis of Burrows-Wheeler based compression. Theor. Comput. Sci. 387(3), 220–235 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  39. Karlin, A.R., Phillips, S.J., Raghavan, P.: Markov paging. SIAM J. Comput. 30(3), 906–922 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  40. Kenyon, C.: Best-fit bin-packing with random order. In: ACM-SIAM SODA ’96, pp. 359–364 (1996)

  41. Koutsoupias, E., Papadimitriou, C.: Beyond competitive analysis. SIAM J. Comput. 30, 300–317 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  42. Martínez, C., Roura, S.: On the competitiveness of the move-to-front rule. Theor. Comput. Sci. 242(1–2), 313–325 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  43. Megiddo, N., Modha, D.S.: ARC: A self-tuning, low overhead replacement cache. In: Proceedings of the FAST ’03 Conference on File and Storage Technologies (2003)

  44. Munro, J.I.: On the competitiveness of linear search. In: Proceedings of the 8th Annual European Symposium on Algorithms (ESA ’00). volume 1879 of Lecture Notes in Computer Science, pp. 338–345 (2000)

  45. O’Neil, E.J., O’Neil, P.E., Weikum, G.: An optimality proof of the LRU-K page replacement algorithm. J. ACM 46(1), 92–112 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  46. Panagiotou, K., Souza, A.: On adequate performance measures for paging. In: Proceedings of the 38th Annual ACM Symposium on Theory of Computing (STOC ’06), pp. 487–496 (2006)

  47. Reingold, N., Westbrook, J., Sleator, D.D.: Randomized competitive algorithms for the list update problem. Algorithmica 11, 15–32 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  48. Schulz, F.: Two new families of list update algorithms. In: Proceedings of the 9th International Symposium on Algorithms and Computation (ISAAC ’98), volume 1533 of Lecture Notes in Computer Science, pp. 99–108. Springer (1998)

  49. Silberschatz, A., Galvin, P.B., Gagne, G.: Operating System Concepts. Wiley, Hoboken (2002)

    MATH  Google Scholar 

  50. Sleator, D.D., Tarjan, R.E.: Amortized efficiency of list update and paging rules. Commun. ACM 28, 202–208 (1985)

    Article  MathSciNet  Google Scholar 

  51. Torng, E.: A unified analysis of paging and caching. Algorithmica 20(2), 175–200 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  52. Witten, I.H., Bell, T.: The Calgary/Canterbury text compression corpus. https://urldefense.proofpoint.com/v2/url?u=http-3A__corpus.canterbury.ac.nz_resources_calgary.tar.gz&d=DwICAg&c=vh6FgFnduejNhPPD0fl_yRaSfZy8CWbWnIf4XJhSqx8&r=cijxKIUfIjh6xB35XSxKelnSNfz2185wGO_qFr-DFH8&m=J6RYYpZfpyF_ohIicn6Ok991AGPobbkIOD5buCQJ29Q&s=oH14Kym57oZMk1NpzUHa6ZqQhtV-amaWVPNHH-WJ7-k&e=

  53. Young, N.E.: The \(k\)-server dual and loose competitiveness for paging. Algorithmica 11(6), 525–541 (1994)

    Article  MathSciNet  Google Scholar 

  54. Young, N.E.: Bounding the diffuse adversary. In: Proceedings of the 9th ACM-SIAM Symposium on Discrete Algorithms (SODA ’98), pp. 420–425 (1998)

  55. Young, N.E.: On-line paging against adversarially biased random inputs. J. Algorithms 37(1), 218–235 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  56. Young, N.E.: On-line file caching. Algorithmica 33(3), 371–383 (2002)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgements

We are grateful to an anonymous referee for the extraordinary effort and care that gave to this paper; the in-depth comments of this referee helped improve substantially the paper’s overall quality, and in particular, the proof of Theorem 2. We also thank Ian Munro for early discussions on alternative measures of performance for online algorithms, as well as Joan Boyar and Kim Larsen for many insightful comments on an earlier version of this paper. This work was the result of an exciting collaboration with our mentor and friend, Alex López-Ortiz, who sadly passed away before this submission was accepted for publication. We would like to dedicate the final paper to his memory.

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Correspondence to Spyros Angelopoulos.

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In the conference version of this part of the paper [10], it was claimed that MTF is the unique optimal algorithm, however, we cannot reproduce this proof in this paper. We still conjecture that MTF is uniquely optimal under bijective and concave analysis.

This work is an extended, combined version of two papers: On the separation and equivalence of paging strategies, in Proceedings of the Eighteenth Annual ACM-SIAM Symposium on Discrete Algorithms, 2007, pp. 229–237, and List Update with Locality of Reference, in Proceedings of the Eighth Latin American Theoretical Informatics Symposium, 2008, pp. 399–410.

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Angelopoulos, S., Dorrigiv, R. & López-Ortiz, A. On the Separation and Equivalence of Paging Strategies and Other Online Algorithms. Algorithmica 81, 1152–1179 (2019). https://doi.org/10.1007/s00453-018-0461-2

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