Time, Clocks, and the Ordering of Events in a Distributed System.¶
Lamport, L. (1978). Time, Clocks, and the Ordering of Events in a Distributed System. Communications of the ACM, 21(7), 558-565.
Cited by¶
9 citations across 8 artifacts.
Each citation links to the sentence it supports in the citing article.
Primes¶
- Concurrency
- Time-ordering sensitivity and causality preservation across parallel execution
This sourceDefines the happened-before partial order and logical clocks for ordering distributed events. SUPPORTS marker 049 (time-ordering sensitivity and causality preservation). PARTIALLY SUPPORTS marker 059 (T3: determinism vs nondeterminism) — Lamport gives the causal-ordering framework but does not directly treat testing-interleaving nondeterminism; defensible but indirect. DOI verified. See flag on 059.
SupportedVerified against the work's full text
Lamport examines "one event happening before another in a distributed system" and shows that the relation defines a partial ordering of the events, then gives a distributed algorithm for synchronizing logical clocks that can be used to order events totally. That happened-before ordering and its clock construction are the time-ordering and causality-preservation apparatus the sentence points to. The work bears on ordering and causality rather than on interleaving or nondeterminism, which the citation line attaches to a separate marker.
“a --) b means that it is possible for event a to causally affect event b. Two events are concurrent if neither can causally affect the other.”
- Time-ordering sensitivity and causality preservation across parallel execution
- Local Autonomy & Tiered Escalation
- When well-designed, tiered systems are fast (Tier-1 resolves most issues immediately), efficient (specialists focus on hard problems), and adaptive (escalation criteria can be tuned as conditions change), much as Lamport (1978) demonstrates in his analysis of clocks and event ordering in distributed systems.
This sourceFoundational analysis of distributed systems: local processes act autonomously on local clock state and coordinate only when causal ordering across processes requires it — the distributed-computing analogue of tiered local autonomy with selective escalation.
- When well-designed, tiered systems are fast (Tier-1 resolves most issues immediately), efficient (specialists focus on hard problems), and adaptive (escalation criteria can be tuned as conditions change), much as Lamport (1978) demonstrates in his analysis of clocks and event ordering in distributed systems.
- Polyphony
- Deliberation and pluralist politics. Multi-stakeholder fora and citizen assemblies in which distinct positions must remain audible as their own arguments rather than being pre-aggregated into a single majority view. Organizations. Cross-functional groups in which engineering, design, legal, and sales each speak in their own register; the shared "score" is the product or strategy, not a single hierarchical voice. Distributed systems. Independent processes or services running concurrently on a shared bus or coordination layer, where correctness depends on each holding its own state machine while honoring shared invariants.
This sourceFoundational account of independent concurrent processes coordinating on a shared logical-time substrate while each holds its own state.
Supported in partVerified against the work's full text
Lamport shows independent processes each simulating the same State Machine and coordinating through timestamped message ordering; the paper does not mention a bus or invariants.
“Each process independently simulates the execution of the State Machine, using the commands issued by all the processes.”
- Deliberation and pluralist politics. Multi-stakeholder fora and citizen assemblies in which distinct positions must remain audible as their own arguments rather than being pre-aggregated into a single majority view. Organizations. Cross-functional groups in which engineering, design, legal, and sales each speak in their own register; the shared "score" is the product or strategy, not a single hierarchical voice. Distributed systems. Independent processes or services running concurrently on a shared bus or coordination layer, where correctness depends on each holding its own state machine while honoring shared invariants.
- Race Condition
- A second abstract move is that races are sensitive to substrate-level guarantees that are invisible at the level of intent: the same protocol can be race-free on a synchronous substrate and race-prone on an asynchronous one, which is the structural reason that moving a working system to a more loosely coordinated environment can introduce races silently in logic that never changed.
This sourceShows that ordering of concurrent events depends on substrate-level guarantees and that bounded delay / logical clocks are needed even to reason about order.
Supported in partVerified against the work's full text
Lamport shows event ordering and correct resource granting depend on assumptions about message delay and clocks, but he does not discuss synchronous versus asynchronous substrates or silent migration races.
“Using a central scheduling process which grants requests in the order they are received will not work, unless additional assumptions are made.”
- A second abstract move is that races are sensitive to substrate-level guarantees that are invisible at the level of intent: the same protocol can be race-free on a synchronous substrate and race-prone on an asynchronous one, which is the structural reason that moving a working system to a more loosely coordinated environment can introduce races silently in logic that never changed.
- Synchronization
- Computer science & distributed systems: Network Time Protocol (NTP) and Precision Time Protocol (PTP) synchronize clocks across geographically dispersed servers; Lamport (1978) logical clocks and vector clocks provide causality without requiring physical time agreement; consensus protocols (Paxos, Raft) solve the distributed-consensus problem by achieving agreement on state despite asynchrony; thread synchronization (locks, barriers, semaphores, condition variables) ensures that concurrent threads access shared resources in consistent order.
This sourceFoundational analysis of distributed systems: local processes act autonomously on local clock state and coordinate only when causal ordering across processes requires it — the distributed-computing analogue of tiered local autonomy with selective escalation.
Supported in partVerified against the work's full text
Lamport supplies the logical-clock result: ordering events and synchronizing processes without relying on physical time agreement.
“We cannot base our definition of correctness on physical time, since that would require introducing clocks which keep physical time.”
- But modern consensus protocols (Paxos, Raft) go further: they achieve agreement on state Order using logical clocks, without requiring tight physical synchronization—an architecture made possible by Lamport's (1978) demonstration that the happens-before relation is sufficient for distributed causality.
This sourceDemonstrates that consensus and state-order agreement in distributed systems can be achieved using logical clocks alone, without tight physical clock synchronization—the theoretical foundation underlying Paxos and Raft.
Supported in partVerified against the work's full text
Lamport shows logical-clock timestamps give all processes the same command order; he does not treat consensus or Paxos/Raft, and the method assumes no failures.
“Synchronization is achieved because all processes order the commands according to their time- stamps”
- Computer science & distributed systems: Network Time Protocol (NTP) and Precision Time Protocol (PTP) synchronize clocks across geographically dispersed servers; Lamport (1978) logical clocks and vector clocks provide causality without requiring physical time agreement; consensus protocols (Paxos, Raft) solve the distributed-consensus problem by achieving agreement on state despite asynchrony; thread synchronization (locks, barriers, semaphores, condition variables) ensures that concurrent threads access shared resources in consistent order.
- Temporal Synchronization and Phase Alignment
- In the first case, synchronization suffices as a concept; in the second case, phase alignment is the critical structural property.
This sourceFoundational analysis of distributed systems: local processes act autonomously on local clock state and coordinate only when causal ordering across processes requires it — the distributed-computing analogue of tiered local autonomy with selective escalation.
- In the first case, synchronization suffices as a concept; in the second case, phase alignment is the critical structural property.
Domain-specific¶
Verification¶
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Does it back the claim? Read against the text for 6 of 9 citations: 1 supported, 5 supported in part. Each verdict is shown under its citation below, with what in the work backs the sentence.
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