FA-10281 / Observability / Open access

Structured log emission policy: Logs exactly at threshold disappear · case 01

Logs exactly at threshold disappear.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation substitutes event['level'] > threshold for event['level'] >= threshold, so logs exactly at threshold disappear.

VERIFIED REPAIR

Use an inclusive minimum severity.

Unsuccessful approach: The attempted repair substitutes event['level'] == threshold. Fixture 3 still yields False instead of True.

Case contract

Emit a log only when severity reaches the threshold, logger is enabled, sampling selected it, it is not suppressed, and all required fields exist. False-valued fields count as present.

Why this case matters

An offline model of structured log emission policy, suitable for testing build and release tooling without external services.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(event, threshold, enabled, sampled, suppressed, required):
    return event['level'] > threshold and enabled and sampled and not suppressed and set(required) <= set(event)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'level': 2, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 2', solve({'level': 1, 'message': 'x'}, 2, True, True, False, ['message']), False)
check('fixture 3', solve({'level': 3, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 4', solve({'level': 2, 'message': 'x'}, 2, False, True, False, ['message']), False)
check('fixture 5', solve({'level': 2, 'message': 'x'}, 2, True, False, False, ['message']), False)
check('fixture 6', solve({'level': 2, 'message': 'x'}, 2, True, True, True, ['message']), False)
check('fixture 7', solve({'level': 2}, 2, True, True, False, ['message']), False)
check('fixture 8', solve({'level': 2, 'message': False}, 2, True, True, False, ['message']), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 1	`False`	`True`	Failed
fixture 2	`False`	`False`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`False`	`False`	Passed
fixture 5	`False`	`False`	Passed
fixture 6	`False`	`False`	Passed
fixture 7	`False`	`False`	Passed
fixture 8	`False`	`True`	Failed

SHA-256 / e8510d15b07f32e8ae1936a7e0cc0393eed5fe80a80b58e8793941c6a5078cef

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(event, threshold, enabled, sampled, suppressed, required):
    return event['level'] == threshold and enabled and sampled and not suppressed and set(required) <= set(event)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'level': 2, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 2', solve({'level': 1, 'message': 'x'}, 2, True, True, False, ['message']), False)
check('fixture 3', solve({'level': 3, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 4', solve({'level': 2, 'message': 'x'}, 2, False, True, False, ['message']), False)
check('fixture 5', solve({'level': 2, 'message': 'x'}, 2, True, False, False, ['message']), False)
check('fixture 6', solve({'level': 2, 'message': 'x'}, 2, True, True, True, ['message']), False)
check('fixture 7', solve({'level': 2}, 2, True, True, False, ['message']), False)
check('fixture 8', solve({'level': 2, 'message': False}, 2, True, True, False, ['message']), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 1	`True`	`True`	Passed
fixture 2	`False`	`False`	Passed
fixture 3	`False`	`True`	Failed
fixture 4	`False`	`False`	Passed
fixture 5	`False`	`False`	Passed
fixture 6	`False`	`False`	Passed
fixture 7	`False`	`False`	Passed
fixture 8	`True`	`True`	Passed

SHA-256 / baf06cbee527096c9f52ddeb81330d3fcb4c792680aad99b3fc60881c71a3173

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(event, threshold, enabled, sampled, suppressed, required):
    return event['level'] >= threshold and enabled and sampled and not suppressed and set(required) <= set(event)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve({'level': 2, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 2', solve({'level': 1, 'message': 'x'}, 2, True, True, False, ['message']), False)
check('fixture 3', solve({'level': 3, 'message': 'x'}, 2, True, True, False, ['message']), True)
check('fixture 4', solve({'level': 2, 'message': 'x'}, 2, False, True, False, ['message']), False)
check('fixture 5', solve({'level': 2, 'message': 'x'}, 2, True, False, False, ['message']), False)
check('fixture 6', solve({'level': 2, 'message': 'x'}, 2, True, True, True, ['message']), False)
check('fixture 7', solve({'level': 2}, 2, True, True, False, ['message']), False)
check('fixture 8', solve({'level': 2, 'message': False}, 2, True, True, False, ['message']), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 1	`True`	`True`	Passed
fixture 2	`False`	`False`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`False`	`False`	Passed
fixture 5	`False`	`False`	Passed
fixture 6	`False`	`False`	Passed
fixture 7	`False`	`False`	Passed
fixture 8	`True`	`True`	Passed

SHA-256 / f4bbb946152e17c26a856a860be6e984a70a96eaa3cc9b26f45ef7745c0f0652

Verification & scope

This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:37.492208+00:00.

Case digest / 09013b4bb288cfd5cb4e7cfc58977296656f0f0e3232fde9cec78995ba490502