FAILURE MAP
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FA-6726 / HTTP caching / Open access

Age includes response delay after corrected received age · case 01

Age includes response delay after corrected received age.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The faulty implementation uses `max(apparent,age)+delay` for the age-includes-response-delay-after-corrected-received-age decision.

VERIFIED REPAIR

Apply the explicit age-includes-response-delay-after-corrected-received-age contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `apparent+age+delay` and still violates a separate fixture.

Case contract

Bounded offline decision model: age includes response delay after corrected received age. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic http caching model isolates the age-includes-response-delay-after-corrected-received-age policy at a network component boundary.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(apparent, age, delay):
    return max(apparent,age)+delay
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(10, 2, 3), 10)", "check('fixture 2', solve(2, 10, 3), 13)", "check('fixture 3', solve(0, 0, 0), 0)", "check('fixture 4', solve(5, 5, 2), 7)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 fixtureActualExpectedOutcome
fixture 21313Passed
fixture 300Passed
fixture 477Passed
fixture 11310Failed

SHA-256 / b5e290f3a4e61fc7b0497497b0e1debfa9606f7f60963f083e15b473d8d96d64

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(apparent, age, delay):
    return apparent+age+delay
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(10, 2, 3), 10)", "check('fixture 2', solve(2, 10, 3), 13)", "check('fixture 3', solve(0, 0, 0), 0)", "check('fixture 4', solve(5, 5, 2), 7)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 fixtureActualExpectedOutcome
fixture 21513Failed
fixture 300Passed
fixture 4127Failed
fixture 11510Failed

SHA-256 / 96d649d35be9045e8c9960833d12222618e9ca79a6b45c503a97a0e15e3d3687

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(apparent, age, delay):
    return max(apparent,age+delay)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(10, 2, 3), 10)", "check('fixture 2', solve(2, 10, 3), 13)", "check('fixture 3', solve(0, 0, 0), 0)", "check('fixture 4', solve(5, 5, 2), 7)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 fixtureActualExpectedOutcome
fixture 21313Passed
fixture 300Passed
fixture 477Passed
fixture 11010Passed

SHA-256 / 460f814349eca7dbc3928b815c2adef94867f8e99624c6caea7edf3ed69180f5

Verification & scope

Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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 2026-09-29T14:38:04.624110+00:00.

Case digest / cb16d03d452ef71468b8a6853cad9e40825ba8c7c3096e89afefeca5c45b522a