FAILURE MAP
← Case archive

FA-7711 / Connection lifecycle / Open access

Connection pool key includes scheme host and port · case 01

Connection pool key includes scheme host and port.

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

ROOT CAUSE

The faulty implementation uses `host.lower()` for the connection-pool-key-includes-scheme-host-and-port decision.

VERIFIED REPAIR

Apply the explicit connection-pool-key-includes-scheme-host-and-port contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `(host.lower(),port)` and still violates a separate fixture.

Case contract

Bounded offline decision model: connection pool key includes scheme host and port. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic connection lifecycle model isolates the connection-pool-key-includes-scheme-host-and-port 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(scheme, host, port):
    return host.lower()
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('https', 'EXAMPLE', 443), ('https', 'example', 443))", "check('fixture 2', solve('http', 'example', 443), ('http', 'example', 443))", "check('fixture 3', solve('https', 'example', 8443), ('https', 'example', 8443))", "check('fixture 4', solve('http', 'x', 80), ('http', 'x', 80))"]
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 2example['http', 'example', 443]Failed
fixture 3example['https', 'example', 8443]Failed
fixture 4x['http', 'x', 80]Failed
fixture 1example['https', 'example', 443]Failed

SHA-256 / 755f50a2adcab94b1cce3133ddc18a7376325e6d36151b0955b90e291f3595ad

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(scheme, host, port):
    return (host.lower(),port)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('https', 'EXAMPLE', 443), ('https', 'example', 443))", "check('fixture 2', solve('http', 'example', 443), ('http', 'example', 443))", "check('fixture 3', solve('https', 'example', 8443), ('https', 'example', 8443))", "check('fixture 4', solve('http', 'x', 80), ('http', 'x', 80))"]
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 2['example', 443]['http', 'example', 443]Failed
fixture 3['example', 8443]['https', 'example', 8443]Failed
fixture 4['x', 80]['http', 'x', 80]Failed
fixture 1['example', 443]['https', 'example', 443]Failed

SHA-256 / 8b8069ea52a0a334030a68d40a014cbe9b57f79c72ff984efe0547b7d61932b1

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(scheme, host, port):
    return (scheme,host.lower(),port)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('https', 'EXAMPLE', 443), ('https', 'example', 443))", "check('fixture 2', solve('http', 'example', 443), ('http', 'example', 443))", "check('fixture 3', solve('https', 'example', 8443), ('https', 'example', 8443))", "check('fixture 4', solve('http', 'x', 80), ('http', 'x', 80))"]
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 2['http', 'example', 443]['http', 'example', 443]Passed
fixture 3['https', 'example', 8443]['https', 'example', 8443]Passed
fixture 4['http', 'x', 80]['http', 'x', 80]Passed
fixture 1['https', 'example', 443]['https', 'example', 443]Passed

SHA-256 / 055a1f2908eacd8e658615038f53418a12c4b1b70113c4d84ea8ca6b5e8299d6

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 2026-09-29T14:38:14.587646+00:00.

Case digest / 574d29dc5b586574edf10b85aeb9949cac11f52b97d7274db9483800028a8de0