Engineering / advanced
Order and uncertainty without a global clock
Separate causality from wall-clock time, then reason about leases, fencing, deadlines, and uncertainty in distributed execution.
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Module 01 advanced
Order and uncertainty without a global clock
Separate causality from wall-clock time, then reason about leases, fencing, deadlines, and uncertainty in distributed execution.
- 01
Separate clock offset, drift, and synchronization evidence
Calculate a timestamp-exchange estimate while keeping clock-rate bounds, path asymmetry, and elapsed-time clocks distinct.
24 min - 02
Order known dependencies with logical counters
Construct happened-before order and Lamport updates without interpreting counter differences as durations or reversed implications as causality.
24 min - 03
Represent causal history component by component
Use vector updates and componentwise comparison to distinguish ordered events from concurrency under an explicit participant model.
24 min - 04
Combine a physical component with a causal tie-break
Apply hybrid logical clock updates while distinguishing causal monotonicity, physical-clock assumptions, and finite representation limits.
24 min - 05
Make real-time uncertainty part of the commit protocol
Reason from guaranteed time intervals to a commit-wait condition without treating synchronization or sleeping alone as a transaction protocol.
24 min - 06
Bound a lease using explicit clock assumptions
Derive a conservative duration comparison while distinguishing lease authority, process pauses, delayed operations, and safe resource access.
24 min - 07
Enforce authority at the resource with fencing tokens
Use monotonic grant generations to reject stale effects while separating fencing from leases, authorization, and duplicate suppression.
24 min - 08
Treat timeouts as suspicions under a failure model
Distinguish delayed evidence from crash proof, relate completeness and accuracy, and calculate a narrowly specified false-suspicion model.
24 min - 09
Carry a time budget across different clock domains
Propagate remaining work budgets without copying local clock epochs, resetting retries, or mistaking cancellation for rollback.
24 min - 10
Reconstruct a partial order without inventing missing history
Combine local sequence, correlated messages, vector histories, and clock intervals while preserving unknown relationships in incomplete traces.
24 min