Logical Time and Causality¶

Since physical time is unreliable, logical clocks track causality - the "happens-before" relationship captures what events could have influenced others, providing ordering guarantees without synchronized clocks.

Tension Addressed¶

Consistency vs. Latency

Recognizable As¶

Lamport timestamps; vector clocks; version vectors; causal consistency guarantees; conflict detection in collaborative systems; event ordering in message queues

Canonical Sources¶

Lamport, "Time, Clocks, and the Ordering of Events in a Distributed System" (1978); Fidge, "Timestamps in Message-Passing Systems" (1988); Mattern, "Virtual Time and Global States of Distributed Systems" (1989)

Transfers To¶

Distributed databases, version control systems, collaborative editing, event sourcing, conflict-free replicated data types

Sub-concepts: - Lamport clocks: Single counter, provides total order but may order unrelated events - Vector clocks: Counter per node, detects concurrency (events neither before nor after each other) - Happens-before: Partial order defining causal relationships