On the minimal synchronism needed for distributed consensus
Journal of the ACM (JACM)
On the possibility and impossibility of achieving clock synchronization
Journal of Computer and System Sciences
Consensus in the presence of partial synchrony
Journal of the ACM (JACM)
Bounds on the time to reach agreement in the presence of timing uncertainty
Journal of the ACM (JACM)
Impossibility of distributed consensus with one faulty process
Journal of the ACM (JACM)
Unreliable failure detectors for reliable distributed systems
Journal of the ACM (JACM)
The message classification model
PODC '98 Proceedings of the seventeenth annual ACM symposium on Principles of distributed computing
Fault-tolerant broadcasts and related problems
Distributed systems (2nd Ed.)
Time, clocks, and the ordering of events in a distributed system
Communications of the ACM
Semisynchrony and Real-Time (Extended Abstract)
WDAG '92 Proceedings of the 6th International Workshop on Distributed Algorithms
Proceedings of the 13th International Symposium on Distributed Computing
DISC '01 Proceedings of the 15th International Conference on Distributed Computing
Synchronous System and Perfect Failure Detector: Solvability and Efficiency Issue
DSN '00 Proceedings of the 2000 International Conference on Dependable Systems and Networks (formerly FTCS-30 and DCCA-8)
Distributed elections in an archimedean ring of processors
STOC '84 Proceedings of the sixteenth annual ACM symposium on Theory of computing
A necessary and sufficient condition for transforming limited accuracy failure detectors
Journal of Computer and System Sciences
Communication-efficient leader election and consensus with limited link synchrony
Proceedings of the twenty-third annual ACM symposium on Principles of distributed computing
Proceedings of the twenty-third annual ACM symposium on Principles of distributed computing
A formal approach to designing delay-insensitive circuits
Distributed Computing
On the Possibility of Consensus in Asynchronous Systems with Finite Average Response Times
ICDCS '05 Proceedings of the 25th IEEE International Conference on Distributed Computing Systems
Consensus with Byzantine Failures and Little System Synchrony
DSN '06 Proceedings of the International Conference on Dependable Systems and Networks
VLSI Implementation of a Fault-Tolerant Distributed Clock Generation
DFT '06 Proceedings of the 21st IEEE International Symposium on on Defect and Fault-Tolerance in VLSI Systems
Fault-Tolerant Distributed Clock Generation in VLSI Systems-on-Chip
EDCC '06 Proceedings of the Sixth European Dependable Computing Conference
Optimal message-driven implementations of omega with mute processes
ACM Transactions on Autonomous and Adaptive Systems (TAAS)
Chasing the Weakest System Model for Implementing Ω and Consensus
IEEE Transactions on Dependable and Secure Computing
Optimal message-driven implementation of omega with mute processes
SSS'06 Proceedings of the 8th international conference on Stabilization, safety, and security of distributed systems
Brief announcement: chasing the weakest system model for implementing Ω and consensus
SSS'06 Proceedings of the 8th international conference on Stabilization, safety, and security of distributed systems
Optimal clock synchronization revisited: upper and lower bounds in real-time systems
OPODIS'06 Proceedings of the 10th international conference on Principles of Distributed Systems
Failure detection with booting in partially synchronous systems
EDCC'05 Proceedings of the 5th European conference on Dependable Computing
Hi-index | 5.24 |
This paper shows how synchrony conditions can be added to the purely asynchronous model in a way that avoids any reference to message delays and computing step times, as well as system-wide constraints on execution patterns and network topology. Our Asynchronous Bounded-Cycle (ABC) model just bounds the ratio of the number of forward- and backward-oriented messages in certain (''relevant'') cycles in the space-time diagram of an asynchronous execution. We show that clock synchronization and lock-step rounds can be implemented and proved correct in the ABC model, even in the presence of Byzantine failures. Furthermore, we prove that any algorithm working correctly in the partially synchronous @Q-Model also works correctly in the ABC model. In our proof, we first apply a novel method for assigning certain message delays to asynchronous executions, which is based on a variant of Farkas' theorem of linear inequalities and a non-standard cycle space of graphs. Using methods from point-set topology, we then prove that the existence of this delay assignment implies model indistinguishability for time-free safety and liveness properties. We also introduce several weaker variants of the ABC model, and relate our model to the existing partially synchronous system models, in particular, the classic models of Dwork, Lynch and Stockmayer and the query-response model by Mostefaoui, Mourgaya, and Raynal. Finally, we discuss some aspects of the ABC model's applicability in real systems, in particular, in the context of VLSI Systems-on-Chip.