fix(audit): grow writeAuditEntry 412 backoff to exponential jitter - #277
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Bursts of PreconditionFailed on the per-file audit.txt If-Match write hit 5011/24h on 2026-05-12 (1929/24h the day before) - the existing linear 0-50/0-100/0-150/0-200 ms jitter (~500 ms total) does not spread retries far enough across the contention window. Switch to exponential jitter 0-50/0-100/0-200/0-400 ms (~750 ms total, i.e. Math.random() * 50 * 2**attempt). Retry count unchanged (4 retries, 5 total attempts). Early retries stay cheap; late retries get the headroom. New test stubs setTimeout + Math.random to capture per-retry delays and asserts the per-attempt upper bounds plus that total elapsed sleep exceeds the prior linear worst-case (500 ms). All 390 existing tests continue to pass. Co-Authored-By: Paperclip <noreply@paperclip.ing>
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## [1.8.2](v1.8.1...v1.8.2) (2026-05-12) ### Bug Fixes * **audit:** grow writeAuditEntry 412 backoff to exponential jitter ([#277](#277)) ([17aac95](17aac95))
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Post-deploy verification (release v1.8.2)Re-ran the canonical Coralogix query for da-admin writeAuditEntry failed and the paired da-collab signal after merge + deploy:
The 24h / 6h totals are dominated by the pre-merge burst. The cutover is sharp: rate goes to 0 between the 2h and 1h windows, which lines up with the v1.8.2 release deploy after this PR merged. Before/after:
Both signals materially dropped, which is the COR-26 acceptance criterion. |
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…282) * fix(audit): grow writeAuditEntry 412 backoff to 6 retries / ~3050 ms The previous mitigation (PR #277) widened the backoff from linear (~500 ms) to exponential jitter (~750 ms worst-case) but kept the 4-retry cap. Six days after that deploy the writeAuditEntry PreconditionFailed rate is still sustained at ~5614/24h on a hot audit ledger key, indicating that the contention window is wider than the per-write latency: every retry inside a short window observes the same losing-etag generation, so timing knobs alone have not converged. This change adds two more retry hops to the same exponential jitter formula, so the worst-case sleep ladder per attempt is now: 50, 100, 200, 400, 800, 1600 ms (~3050 ms total) The intent is reversible diagnostic data: if the rate does not drop below the <250/24h target after this, the next escalation is an append-only ledger layout (one S3 object per audit entry under the existing audit dir prefix) which eliminates the read-modify-write race entirely. Tests updated to assert the new contract (7 total attempts, 6 retries, new exponential ceiling) and an additional lockdown that delay[5] reaches the new ~800 ms floor on the final hop. Co-Authored-By: Paperclip <noreply@paperclip.ing> * test(audit): align conditionals PUT-with-If-Match test with 6-retry budget The audit retry bump (4 -> 6 with exponential jitter, PR #282) raised the worst-case write-audit budget from ~750 ms to ~3050 ms. "PUT with If-Match: returns 412 when ETag does not match and does not retry" mocks every PutObjectCommand to 412 so the audit writer exhausts its full retry budget. Two consequences after the bump: - Total PutObjectCommand calls: 6 -> 8 (1 main PUT + 7 audit attempts = 1 initial + 6 retries). - Wall time exceeds mocha's 2000 ms default, causing a timeout failure. Updated the count assertion and added `this.timeout(8000)` so the test covers the new 6-retry path without flaking. Co-Authored-By: Paperclip <noreply@paperclip.ing> --------- Co-authored-by: Paperclip <noreply@paperclip.ing>
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Summary
Why
Daily DA worker log review on 2026-05-12 measured writeAuditEntry failed / PreconditionFailed at 5011/24h (and climbing in-flight). The previous day was 1929/24h. Two consecutive days > 250/24h is the explicit re-tune trigger from the monitoring issue. The merged #274 backoff (~500ms total) is not enough headroom during burst contention.
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