Sparse time versus dense time in distributed real-time systems

The restriction of the significant event occurrences, i.e., the sending and receiving of messages in a distributed real-time system, to the lattice points of a globally synchronized space/time lattice are discussed. One dimension of this space/time lattice represents the progression of time, the other dimension denotes the computational processes in the system. It is shown that this additional constraint simplifies solutions to agreement problems. After an analysis of the interdependence among temporal order, causal order, receive order, and the limits of time measurement in a distributed real-time system, criteria for the selection of the lattice points of this space/time lattice are presented.<<ETX>>

[1]  Paulo Veríssimo,et al.  The Delta-4 extra performance architecture (XPA) , 1990, [1990] Digest of Papers. Fault-Tolerant Computing: 20th International Symposium.

[2]  Hermann Kopetz,et al.  Clock Synchronization in Distributed Real-Time Systems , 1987, IEEE Transactions on Computers.

[3]  Nicolas Halbwachs,et al.  LUSTRE: A declarative language for programming synchronous systems* , 1987 .

[4]  J. Moss.  THE NATURAL PHILOSOPHY OF TIME , 1962 .

[5]  Leslie Lamport,et al.  Time, clocks, and the ordering of events in a distributed system , 1978, CACM.

[6]  Gérard Berry,et al.  The Esterel Synchronous Programming Language: Design, Semantics, Implementation , 1992, Sci. Comput. Program..

[7]  Leslie Lamport,et al.  Using Time Instead of Timeout for Fault-Tolerant Distributed Systems. , 1984, TOPL.

[8]  F. Rawlins.  The Philosophy of Space and Time , 1959 .

[9]  K. H. Kim,et al.  Temporal uncertainties in interactions among real-time objects , 1990, Proceedings Ninth Symposium on Reliable Distributed Systems.

[10]  Hermann Kopetz,et al.  Fault-Tolerant Membership Service in a Synchronous Distributed Real-Time System , 1991 .

[11]  M. Raynal.  Order notions and atomic multicast in distributed systems: a short survey , 1990, [1990] Proceedings. Second IEEE Workshop on Future Trends of Distributed Computing Systems.

[12]  Hermann Kopetz,et al.  Distributed fault-tolerant real-time systems: the Mars approach , 1989, IEEE Micro.

[13]  Ajay D. Kshemkalyani,et al.  A basic unit of computation in distributed systems , 1990, Proceedings.,10th International Conference on Distributed Computing Systems.