Keeping track of the latest gossip: Bounded time-stamps suffice

  • Madhavan Mukund
  • Milind Sohoni
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 761)


Consider a distributed system consisting of N independent communicating agents. Periodically, agents synchronize and exchange information, both about each other and about agents they have talked to earlier. As a result, an agent a t may receive indirect information about another agent a j which is more recent than the information exchanged in the last direct synchronization between a i and a j . The problem is to ensure that agents always come away from a synchronization with the latest possible information about all other agents. This requires that when a i and a j meet, they should decide which of them has more recent information about any other agent a k . We propose an algorithm to solve this problem which is finite-state and local. Formally, this means our algorithm can be implemented by an asynchronous automaton.


Distributed algorithms synchronous communication bounded time-stamping asynchronous automata 


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  1. [CS]
    R. Cori, E. Sopena: Some combinatorial aspects of time-stamp systems, Europ. J. Combinatorics, 14 (1993) 95–102.Google Scholar
  2. [DM]
    V. Diekert, A. Muscholl: Deterministic asynchronous automata for infinite traces, Proc. STACS '93, LNCS 665 (1993) 617–628.Google Scholar
  3. [DS]
    D. Dolev, N. Shavit: Bounded concurrent time-stamps are constructible, Proc. ACM STOC (1989) 454–466.Google Scholar
  4. [GP]
    P. Gastin, A. Petit: Asynchronous cellular automata for infinite traces, Proc. ICALP '92, LNCS 623 (1992) 583–594.Google Scholar
  5. [GW]
    P. Godefroid, P. Wolper: A partial order approach to model checking, Proc. 6th IEEE LICS, Amsterdam (1991) 406–415.Google Scholar
  6. [IL]
    A. Israeli, M. Li: Bounded time-stamps, Proc. 28th IEEE FOCS (1987) 371–382.Google Scholar
  7. [Maz]
    A. Mazurkiewicz: Basic notions of trace theory, in: J.W. de Bakker, W.-P. de Roever, G. Rozenberg (eds.), Linear time, branching time and partial order in logics and models for concurrency, LNCS 354, (1989) 285–363.Google Scholar
  8. [MS]
    M. Mukund, M. Sohoni: Keeping track of the latest gossip: Bounded timestamps suffice, Report TCS-93-3, School of Mathematics, SPIC Science Foundation, Madras, India (1993).Google Scholar
  9. [T]
    P.S. Thiagarajan: A trace based extension of PTL, Report TCS-93-4, School of Mathematics, SPIC Science Foundation, Madras, India (1993).Google Scholar
  10. [Z]
    W. Zielonka: Notes on finite asynchronous automata, R.A.I.R.O.—Inf. Théor. et Appl., 21 (1987) 99–135.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • Madhavan Mukund
    • 1
  • Milind Sohoni
    • 1
  1. 1.School of MathematicsSPIC Science FoundationMadrasIndia

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