Audit Log Review¶
Evidence review — instantiates Reconciliation After Drift
Replays an append-only event history to reconstruct how two records drifted apart, classifying the cause so the correct prior state can be restored and the leak sealed.
Audit Log Review is the forensic step of reconciliation: it does not decide who wins or write the repaired record, it reconstructs how the drift happened by replaying the immutable event history and reading off which change, at which moment, by which actor, caused the divergence. Its defining move is causal reconstruction from an append-only log — the log is trusted as evidence precisely because it cannot be edited, so it can testify to a sequence the current mutable records no longer reveal. From that reconstruction it does three things nothing else in the cycle does: it classifies the cause of each difference (a missing event, a duplicate, an unauthorized change, a benign timing lag), it identifies the correct prior state to restore to when the live value is wrong, and it feeds the root cause into upstream prevention. It supplies the evidence a repair is built on; it is not itself the repair.
Example¶
A platform team notices two microservices disagree about a customer's plan: the billing service shows tier: pro, the provisioning service shows tier: free, and the customer is being charged for features they cannot use. Which value is right — and how did they diverge? Audit Log Review replays the append-only change log across both services. It reconstructs the sequence: an upgrade event fired at 02:14, billing consumed it and moved to pro, but the provisioning service's consumer had crashed during a deploy window and never processed that event — a missing event, not a conflicting edit. That classification matters, because it tells the team the correct state is pro and the restore path is to replay the dropped event into provisioning, not to overwrite billing. The review then reads the deploy log and finds the consumer had no dead-letter retry, so the same drop would recur on the next crash — a root cause fed straight into a prevention change (add retry + alerting on consumer lag). The review produced no reconciled record and picked no authority by fiat; it produced the evidence — cause, correct prior state, and the leak to seal.
How it works¶
- Trust the immutable trail. Take the append-only log, not the mutable records, as the evidence — its whole value is that it preserves the sequence the current state has overwritten.
- Replay to the divergence. Walk the events across both representations to the point where they parted, reconstructing what each side did and when.
- Classify the cause. Name the class of divergence — missing event, duplicate, out-of-order apply, unauthorized mutation, benign timing lag — because the class dictates the correct fix.
- Point at the prior state and the leak. Identify the known-good state to restore to, and hand the root cause to whoever owns the upstream control that let the drift through.
Tuning parameters¶
- Log retention depth — how far back the history is kept; deep retention reconstructs older drift but costs storage and search time, and a reconstruction can never reach past where the log begins.
- Event granularity — field-level change events versus coarse record-level snapshots; fine granularity pinpoints the exact mutation but multiplies log volume.
- Correlation keys — which identifiers stitch events across systems into one timeline; weak keys leave the sequence ambiguous and the cause unprovable.
- Reconstruction scope — replay only the disputed field's events versus the full surrounding context; narrow scope is fast but can miss the real precipitating change.
- Tamper-evidence strength — whether the log is merely append-only or cryptographically chained; stronger integrity makes the reconstruction defensible under challenge.
When it helps, and when it misleads¶
Its strength is answering why, not just what: by replaying an event-sourced[n1] history it turns "the records disagree" into "here is the exact change that caused it, here is the state before it, and here is the control that failed" — the difference between patching a symptom and understanding it. It is indispensable when the correct repair depends on knowing how the drift arose, and when a divergence must be explained to an auditor rather than merely cleared.
Its failure mode is over-trusting the log: an incomplete trail (events that were never logged, or a gap during an outage) invites a confident reconstruction of a sequence that is actually partial, and a mutable or forgeable log can be reconstructed into a story that never happened. A subtler trap is mistaking correlation for cause — reading the last event before the divergence as its cause when the real precipitant went unlogged. The classic misuse is treating a plausible replay as proof and restoring to a "prior state" the log only appeared to establish. The guarding discipline is to corroborate the reconstruction against an independent record where stakes are high, treat log gaps as unknowns rather than filling them, and prefer tamper-evident logging wherever a reconstruction may be challenged.
How it implements the components¶
difference_classification— the core output: reconstructing the event history to name what kind of divergence occurred (missing event, duplicate, unauthorized change, timing lag), since the class determines the correct repair.recurrence_prevention_trigger— the reconstructed root cause is handed to the owner of the upstream control that failed, converting one incident into an upstream fix.rollback_or_restore_path— the history identifies the known-good prior state to restore to when the live value is the wrong one, giving the repair a safe target rather than a guess.
It does NOT implement reconciliation_record or exception_owner — assembling the repaired, inspectable record and assigning an accountable owner to unresolved gaps is Custody Chain Reconciliation; nor does it declare source_authority, which Source-of-Truth Table owns. This review produces the evidence and the cause; another mechanism records the repair and names its owner.
Related¶
- Instantiates: Reconciliation After Drift — the forensic reconstruction that tells a repair how the drift arose and what to restore to.
- Sibling mechanisms: Ledger Reconciliation Workflow · Inventory Count Reconciliation · Custody Chain Reconciliation · Three-Way Merge · Source-of-Truth Table
Editorial Notes¶
Form Classification¶
Form family: Assessment, Review & Assurance
Rationale: Replays an append-only event history to reconstruct how two records drifted apart, classifying the cause so the correct prior state can be restored and the leak sealed, making its operative form a bounded evaluation of existing evidence or work that produces a finding or disposition.
Independent corroboration: The frozen evidence defines Audit Log Review as 'Replays an append-only event history to reconstruct how two records drifted apart, classifying the cause so the correct prior state can be restored and the leak sealed', so its operative form is Assessment, Review & Assurance.
Review outcome: Independent reviewer agreement; high confidence.
Origin Attribution¶
Primary origin: Computer Science & Software Engineering
Origin pattern: Convergent development
Present-day reach: Specialized
Rationale: Event sourcing and systems forensics reconstruct past state by replaying immutable event histories.
Related originating lineages:
- Accounting & Auditing — Reconciliation practice identifies and repairs record divergence from transaction trails.
- Criminology & Forensic Studies — Forensic investigation classifies causes and handling anomalies from an evidentiary sequence.
- Security Studies & Intelligence Analysis — Forensic log review contributes investigation of anomalous handling events.
Review resolution: Computer science is the agreed primary lineage. Accounting review, digital forensics, and security incident investigation independently contribute reconstruction and anomaly classification; replaying event histories is established systems practice, not an Encyclopedia invention.
Review outcome: Reconciled after independent review; high confidence.
Notes¶
[n1] An event-sourced (append-only) log records every state change as an immutable event, so the current state is a replay of that history rather than a value overwritten in place. Its reconstructive power is exactly this: because nothing is deleted, a reviewer can rebuild any past state and see precisely which event caused a divergence — impossible when records only hold their latest value. ↩