{"abstract":"Exchange silently routes unmapped keys to receiver zero.","category":"Data systems","checks":7,"contract":"Route [id,key,payload] rows into fixed receiver partitions using a supplied key-to-partition table. Null keys use the explicit null partition; unmapped non-null keys produce UNMAPPED side output. Preserve source order within each receiver, retain empty receivers, and preserve repeated rows.","contract_signature":"d","evaluation_group":"s3-data-systems-partition-exchange-routing","failed_approach":"The null receiver does not stand for unmapped non-null keys.","family":"s3-data-systems-partition-exchange-routing-unknown-route","id":"FA-45766","implementations":{"attempt":{"sha256":"6ac2b057ae1923839f3a312279eb674589e9a14b565f6518124abfff0607835b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        rows,mapping,null_partition,count=d\n        receivers=[[] for _ in range(count)]; rejected=[]\n        for ident,key,payload in rows:\n            if key is None: target=null_partition\n            elif str(key) in mapping: target=mapping[str(key)]\n            else: target=null_partition\n            receivers[target].append([ident,payload])\n        return [receivers,rejected]\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('independent receivers', solve([[[10, 1, 1], [11, 2, 2]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 1]], [[11, 2]], []], []])\n    check('null receiver', solve([[[10, None, 1]], {}, 1, 3]), [[[], [[10, 1]], []], []])\n    check('unmapped', solve([[[10, 7, 1]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 1], [10, 1, 2]], {'1': 0}, 1, 2]), [[[[11, 1], [10, 2]], []], []])\n    check('duplicate rows', solve([[[10, 1, 1], [10, 1, 1]], {'1': 0}, 1, 2]), [[[[10, 1], [10, 1]], []], []])\n    check('mapped zero', solve([[[10, 0, 1]], {'0': 1}, 0, 2]), [[[], [[10, 1]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 2:\n    check('independent receivers', solve([[[10, 1, 2], [11, 2, 3]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 2]], [[11, 3]], []], []])\n    check('null receiver', solve([[[10, None, 2]], {}, 1, 3]), [[[], [[10, 2]], []], []])\n    check('unmapped', solve([[[10, 7, 2]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 2], [10, 1, 3]], {'1': 0}, 1, 2]), [[[[11, 2], [10, 3]], []], []])\n    check('duplicate rows', solve([[[10, 1, 2], [10, 1, 2]], {'1': 0}, 1, 2]), [[[[10, 2], [10, 2]], []], []])\n    check('mapped zero', solve([[[10, 0, 2]], {'0': 1}, 0, 2]), [[[], [[10, 2]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 3:\n    check('independent receivers', solve([[[10, 1, 3], [11, 2, 4]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 3]], [[11, 4]], []], []])\n    check('null receiver', solve([[[10, None, 3]], {}, 1, 3]), [[[], [[10, 3]], []], []])\n    check('unmapped', solve([[[10, 7, 3]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 3], [10, 1, 4]], {'1': 0}, 1, 2]), [[[[11, 3], [10, 4]], []], []])\n    check('duplicate rows', solve([[[10, 1, 3], [10, 1, 3]], {'1': 0}, 1, 2]), [[[[10, 3], [10, 3]], []], []])\n    check('mapped zero', solve([[[10, 0, 3]], {'0': 1}, 0, 2]), [[[], [[10, 3]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 4:\n    check('independent receivers', solve([[[10, 1, 4], [11, 2, 5]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 4]], [[11, 5]], []], []])\n    check('null receiver', solve([[[10, None, 4]], {}, 1, 3]), [[[], [[10, 4]], []], []])\n    check('unmapped', solve([[[10, 7, 4]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 4], [10, 1, 5]], {'1': 0}, 1, 2]), [[[[11, 4], [10, 5]], []], []])\n    check('duplicate rows', solve([[[10, 1, 4], [10, 1, 4]], {'1': 0}, 1, 2]), [[[[10, 4], [10, 4]], []], []])\n    check('mapped zero', solve([[[10, 0, 4]], {'0': 1}, 0, 2]), [[[], [[10, 4]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 5:\n    check('independent receivers', solve([[[10, 1, 5], [11, 2, 6]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 5]], [[11, 6]], []], []])\n    check('null receiver', solve([[[10, None, 5]], {}, 1, 3]), [[[], [[10, 5]], []], []])\n    check('unmapped', solve([[[10, 7, 5]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 5], [10, 1, 6]], {'1': 0}, 1, 2]), [[[[11, 5], [10, 6]], []], []])\n    check('duplicate rows', solve([[[10, 1, 5], [10, 1, 5]], {'1': 0}, 1, 2]), [[[[10, 5], [10, 5]], []], []])\n    check('mapped zero', solve([[[10, 0, 5]], {'0': 1}, 0, 2]), [[[], [[10, 5]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"927acfedc1aa6db7cb54eceb5bea523ed8e55e63641417dd1b4e32f6efb00347","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        rows,mapping,null_partition,count=d\n        receivers=[[] for _ in range(count)]; rejected=[]\n        for ident,key,payload in rows:\n            if key is None: target=null_partition\n            elif str(key) in mapping: target=mapping[str(key)]\n            else: target=0\n            receivers[target].append([ident,payload])\n        return [receivers,rejected]\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('independent receivers', solve([[[10, 1, 1], [11, 2, 2]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 1]], [[11, 2]], []], []])\n    check('null receiver', solve([[[10, None, 1]], {}, 1, 3]), [[[], [[10, 1]], []], []])\n    check('unmapped', solve([[[10, 7, 1]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 1], [10, 1, 2]], {'1': 0}, 1, 2]), [[[[11, 1], [10, 2]], []], []])\n    check('duplicate rows', solve([[[10, 1, 1], [10, 1, 1]], {'1': 0}, 1, 2]), [[[[10, 1], [10, 1]], []], []])\n    check('mapped zero', solve([[[10, 0, 1]], {'0': 1}, 0, 2]), [[[], [[10, 1]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 2:\n    check('independent receivers', solve([[[10, 1, 2], [11, 2, 3]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 2]], [[11, 3]], []], []])\n    check('null receiver', solve([[[10, None, 2]], {}, 1, 3]), [[[], [[10, 2]], []], []])\n    check('unmapped', solve([[[10, 7, 2]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 2], [10, 1, 3]], {'1': 0}, 1, 2]), [[[[11, 2], [10, 3]], []], []])\n    check('duplicate rows', solve([[[10, 1, 2], [10, 1, 2]], {'1': 0}, 1, 2]), [[[[10, 2], [10, 2]], []], []])\n    check('mapped zero', solve([[[10, 0, 2]], {'0': 1}, 0, 2]), [[[], [[10, 2]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 3:\n    check('independent receivers', solve([[[10, 1, 3], [11, 2, 4]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 3]], [[11, 4]], []], []])\n    check('null receiver', solve([[[10, None, 3]], {}, 1, 3]), [[[], [[10, 3]], []], []])\n    check('unmapped', solve([[[10, 7, 3]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 3], [10, 1, 4]], {'1': 0}, 1, 2]), [[[[11, 3], [10, 4]], []], []])\n    check('duplicate rows', solve([[[10, 1, 3], [10, 1, 3]], {'1': 0}, 1, 2]), [[[[10, 3], [10, 3]], []], []])\n    check('mapped zero', solve([[[10, 0, 3]], {'0': 1}, 0, 2]), [[[], [[10, 3]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 4:\n    check('independent receivers', solve([[[10, 1, 4], [11, 2, 5]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 4]], [[11, 5]], []], []])\n    check('null receiver', solve([[[10, None, 4]], {}, 1, 3]), [[[], [[10, 4]], []], []])\n    check('unmapped', solve([[[10, 7, 4]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 4], [10, 1, 5]], {'1': 0}, 1, 2]), [[[[11, 4], [10, 5]], []], []])\n    check('duplicate rows', solve([[[10, 1, 4], [10, 1, 4]], {'1': 0}, 1, 2]), [[[[10, 4], [10, 4]], []], []])\n    check('mapped zero', solve([[[10, 0, 4]], {'0': 1}, 0, 2]), [[[], [[10, 4]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nelif N == 5:\n    check('independent receivers', solve([[[10, 1, 5], [11, 2, 6]], {'1': 0, '2': 1}, 1, 3]), [[[[10, 5]], [[11, 6]], []], []])\n    check('null receiver', solve([[[10, None, 5]], {}, 1, 3]), [[[], [[10, 5]], []], []])\n    check('unmapped', solve([[[10, 7, 5]], {'1': 0}, 1, 2]), [[[], []], [[10, 'UNMAPPED']]])\n    check('same receiver order', solve([[[11, 1, 5], [10, 1, 6]], {'1': 0}, 1, 2]), [[[[11, 5], [10, 6]], []], []])\n    check('duplicate rows', solve([[[10, 1, 5], [10, 1, 5]], {'1': 0}, 1, 2]), [[[[10, 5], [10, 5]], []], []])\n    check('mapped zero', solve([[[10, 0, 5]], {'0': 1}, 0, 2]), [[[], [[10, 5]]], []])\n    check('empty relation', solve([[], {}, 0, 2]), [[[], []], []])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Offline stipulated semantics over valid small inputs; no performance, concurrency, or production-engine conformance claim. 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-data-systems-partition-exchange-routing-unknown-route","generated_at":"2026-09-29T14:44:25.688797+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded deterministic data engine model makes representation and changelog faults reproducible.","root_cause":"partition-exchange-routing: Exchange silently routes unmapped keys to receiver zero.","sha256":"b227b21f8a79ed728fa4bea8093f69cd7427316e83012d2faa4194879cc02b7d","title":"Exchange silently routes unmapped keys to receiver zero · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.922,"exit_code":1,"observations":[{"actual":[[[[10,1]],[[11,2]],[]],[]],"check":"independent receivers","expected":[[[[10,1]],[[11,2]],[]],[]],"passed":true},{"actual":[[[],[[10,1]],[]],[]],"check":"null receiver","expected":[[[],[[10,1]],[]],[]],"passed":true},{"actual":[[[],[[10,1]]],[]],"check":"unmapped","expected":[[[],[]],[[10,"UNMAPPED"]]],"passed":false},{"actual":[[[[11,1],[10,2]],[]],[]],"check":"same receiver order","expected":[[[[11,1],[10,2]],[]],[]],"passed":true},{"actual":[[[[10,1],[10,1]],[]],[]],"check":"duplicate rows","expected":[[[[10,1],[10,1]],[]],[]],"passed":true},{"actual":[[[],[[10,1]]],[]],"check":"mapped zero","expected":[[[],[[10,1]]],[]],"passed":true},{"actual":[[[],[]],[]],"check":"empty relation","expected":[[[],[]],[]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"independent receivers\", \"actual\": [[[[10, 1]], [[11, 2]], []], []], \"expected\": [[[[10, 1]], [[11, 2]], []], []], \"passed\": true}, {\"check\": \"null receiver\", \"actual\": [[[], [[10, 1]], []], []], \"expected\": [[[], [[10, 1]], []], []], \"passed\": true}, {\"check\": \"unmapped\", \"actual\": [[[], [[10, 1]]], []], \"expected\": [[[], []], [[10, \"UNMAPPED\"]]], \"passed\": false}, {\"check\": \"same receiver order\", \"actual\": [[[[11, 1], [10, 2]], []], []], \"expected\": [[[[11, 1], [10, 2]], []], []], \"passed\": true}, {\"check\": \"duplicate rows\", \"actual\": [[[[10, 1], [10, 1]], []], []], \"expected\": [[[[10, 1], [10, 1]], []], []], \"passed\": true}, {\"check\": \"mapped zero\", \"actual\": [[[], [[10, 1]]], []], \"expected\": [[[], [[10, 1]]], []], \"passed\": true}, {\"check\": \"empty relation\", \"actual\": [[[], []], []], \"expected\": [[[], []], []], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.794,"exit_code":1,"observations":[{"actual":[[[[10,1]],[[11,2]],[]],[]],"check":"independent receivers","expected":[[[[10,1]],[[11,2]],[]],[]],"passed":true},{"actual":[[[],[[10,1]],[]],[]],"check":"null receiver","expected":[[[],[[10,1]],[]],[]],"passed":true},{"actual":[[[[10,1]],[]],[]],"check":"unmapped","expected":[[[],[]],[[10,"UNMAPPED"]]],"passed":false},{"actual":[[[[11,1],[10,2]],[]],[]],"check":"same receiver order","expected":[[[[11,1],[10,2]],[]],[]],"passed":true},{"actual":[[[[10,1],[10,1]],[]],[]],"check":"duplicate rows","expected":[[[[10,1],[10,1]],[]],[]],"passed":true},{"actual":[[[],[[10,1]]],[]],"check":"mapped zero","expected":[[[],[[10,1]]],[]],"passed":true},{"actual":[[[],[]],[]],"check":"empty relation","expected":[[[],[]],[]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"independent receivers\", \"actual\": [[[[10, 1]], [[11, 2]], []], []], \"expected\": [[[[10, 1]], [[11, 2]], []], []], \"passed\": true}, {\"check\": \"null receiver\", \"actual\": [[[], [[10, 1]], []], []], \"expected\": [[[], [[10, 1]], []], []], \"passed\": true}, {\"check\": \"unmapped\", \"actual\": [[[[10, 1]], []], []], \"expected\": [[[], []], [[10, \"UNMAPPED\"]]], \"passed\": false}, {\"check\": \"same receiver order\", \"actual\": [[[[11, 1], [10, 2]], []], []], \"expected\": [[[[11, 1], [10, 2]], []], []], \"passed\": true}, {\"check\": \"duplicate rows\", \"actual\": [[[[10, 1], [10, 1]], []], []], \"expected\": [[[[10, 1], [10, 1]], []], []], \"passed\": true}, {\"check\": \"mapped zero\", \"actual\": [[[], [[10, 1]]], []], \"expected\": [[[], [[10, 1]]], []], \"passed\": true}, {\"check\": \"empty relation\", \"actual\": [[[], []], []], \"expected\": [[[], []], []], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}