What is recorded here?
Dwork, Lynch and Stockmeyer define partial synchrony and give deterministic consensus constructions and fault-tolerance bounds when timing bounds are unknown or start holding after an unknown stabilization time. A slow message need not mean a failed computer. Fully asynchronous consensus has a termination obstruction, but practical systems often have more structure than unlimited delays. This paper separates two precise possibilities: timing bounds exist but are unknown, or known bounds eventually hold after an unknown time. It builds protocols and distributed clocks for these settings, keeping agreement safety distinct from eventual decision. The fault threshold changes with the timing and failure model; the paper does not make arbitrary unreliable networks safe merely by waiting longer.
Source-linked catalogue note. A detailed explanatory guide has not yet been prepared for this entry.
Scientific scope
Deterministic fixed-membership, fully connected message-passing models and specified process/delivery bounds are required. Unknown fixed bounds differ from known bounds after unknown GST; the combined processor/communication results use the corresponding declared timing cases. For partially synchronous communication, fail-stop/omission require N>=2 t+1 and Byzantine faults require N>=3 t+1, even with authentication. Synchronous communication with only partial processor synchrony has different thresholds and signed-initial-value/weak-versus-strong unanimity distinctions. In its synchronous-communication omission case, the paper leaves a one-processor gap; this is not a claim that it remains open today. Decide is not halt: with pre-GST message loss, some correct process may have to keep communicating. Polynomial time is relative to N, bounds and GST, not a known deadline from startup. Signatures and sender identity are assumed capabilities; arbitrary Sybil membership, crash recovery and permanently asynchronous termination are excluded. Some clock/protocol proofs are sketched or left to the reader; constants are not fully optimized. No full proof reconstruction, model checking or live-network implementation was certified. Agreement does not establish scientific truth.
Read the original work
- Dwork, Lynch and Stockmeyer, Consensus in the Presence of Partial Synchrony, JACM35(2),288-323,April1988: original article
- Nancy A. Lynch: MIT primary homepage name identification
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People and systems
Cynthia Dwork; Nancy A. Lynch; Larry Stockmeyer
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English catalogue narrative
Dwork, Lynch and Stockmeyer: consensus with partial synchrony
Dwork, Lynch and Stockmeyer define partial synchrony and give deterministic consensus constructions and fault-tolerance bounds when timing bounds are unknown or start holding after an unknown stabilization time.
A slow message need not mean a failed computer. Fully asynchronous consensus has a termination obstruction, but practical systems often have more structure than unlimited delays. This paper separates two precise possibilities: timing bounds exist but are unknown, or known bounds eventually hold after an unknown time. It builds protocols and distributed clocks for these settings, keeping agreement safety distinct from eventual decision. The fault threshold changes with the timing and failure model; the paper does not make arbitrary unreliable networks safe merely by waiting longer.
Scientific scope
Deterministic fixed-membership, fully connected message-passing models and specified process/delivery bounds are required. Unknown fixed bounds differ from known bounds after unknown GST; the combined processor/communication results use the corresponding declared timing cases. For partially synchronous communication, fail-stop/omission require N>=2 t+1 and Byzantine faults require N>=3 t+1, even with authentication. Synchronous communication with only partial processor synchrony has different thresholds and signed-initial-value/weak-versus-strong unanimity distinctions. In its synchronous-communication omission case, the paper leaves a one-processor gap; this is not a claim that it remains open today. Decide is not halt: with pre-GST message loss, some correct process may have to keep communicating. Polynomial time is relative to N, bounds and GST, not a known deadline from startup. Signatures and sender identity are assumed capabilities; arbitrary Sybil membership, crash recovery and permanently asynchronous termination are excluded. Some clock/protocol proofs are sketched or left to the reader; constants are not fully optimized. No full proof reconstruction, model checking or live-network implementation was certified. Agreement does not establish scientific truth.
People and systems
Cynthia Dwork; Nancy A. Lynch; Larry Stockmeyer