{"abstract":"Cancel queued violates retry transition semantics","category":"HTTP retries","checks":8,"contract":"schedule(id,due) replaces an existing queued retry for that ID. cancel(id) removes it and permanently cancels that logical request. poll(now) starts every due noncancelled retry ordered by due then ID and removes it before execution. finish records completion only for running retries. Cancelling running work removes running status; its late completion is ignored. Return start/finish events and pending/running IDs.","evaluation_group":"s3-http_retries-scheduled-cancellation","failed_approach":"The attempted repair changes the faulty site to queued.clear() but still violates a regression oracle.","family":"s3-http_retries-scheduled-cancellation-cancel-queued","id":"FA-29971","implementations":{"attempt":{"sha256":"a59a50a9fd55611df62cb4828ae229f44e81f54395994b25bcd3cb4695521f3e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    queued={}; running=set(); cancelled=set(); out=[]\n    for e in events:\n        if e[0]=='schedule':\n            if e[1] in cancelled: continue\n            if e[1] in running: continue\n            queued[e[1]]=e[2]\n        elif e[0]=='cancel':\n            cancelled.add(e[1])\n            queued.clear()\n            running.discard(e[1])\n        elif e[0]=='poll':\n            ready=sorted((due,k) for k,due in queued.items() if due<=e[1])\n            for due,k in ready:\n                queued.pop(k)\n                running.add(k)\n                out.append(['start',k])\n        elif e[0]=='finish':\n            if e[1] not in running: continue\n            running.remove(e[1])\n            out.append(['finish',e[1]])\n    return [out,sorted(queued),sorted(running)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('cancel','a'),('poll',N+5)]), [[],[],[]])\ncheck('1', solve([]), [[],[],[]])\ncheck('2', solve([('schedule','b',N),('schedule','a',N),('poll',N),('poll',N),('finish','a'),('finish','a')]), [[['start','a'],['start','b'],['finish','a']],[],['b']])\ncheck('3', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('poll',N+5)]), [[['start','a']],[],['a']])\ncheck('4', solve([('schedule','a',1),('schedule','b',2),('cancel','a'),('schedule','a',3),('poll',5)]), [[['start','b']],[],['b']])\ncheck('5', solve([('schedule','a',1),('schedule','b',1),('poll',1),('cancel','a'),('finish','a')]), [[['start','a'],['start','b']],[],['b']])\ncheck('6', solve([('schedule','a',1),('poll',1),('schedule','a',3),('poll',3),('finish','z')]), [[['start','a']],[],['a']])\ncheck('7', solve([('schedule','z',1),('schedule','a',2),('poll',3)]), [[['start','z'],['start','a']],[],['a','z']])\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":"68bbe96e9f4849fee084d5e6adeb68aec5ca2bf2e1963576abcb7d743aa36338","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    queued={}; running=set(); cancelled=set(); out=[]\n    for e in events:\n        if e[0]=='schedule':\n            if e[1] in cancelled: continue\n            if e[1] in running: continue\n            queued[e[1]]=e[2]\n        elif e[0]=='cancel':\n            cancelled.add(e[1])\n            queued.pop(\"all\",None)\n            running.discard(e[1])\n        elif e[0]=='poll':\n            ready=sorted((due,k) for k,due in queued.items() if due<=e[1])\n            for due,k in ready:\n                queued.pop(k)\n                running.add(k)\n                out.append(['start',k])\n        elif e[0]=='finish':\n            if e[1] not in running: continue\n            running.remove(e[1])\n            out.append(['finish',e[1]])\n    return [out,sorted(queued),sorted(running)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('cancel','a'),('poll',N+5)]), [[],[],[]])\ncheck('1', solve([]), [[],[],[]])\ncheck('2', solve([('schedule','b',N),('schedule','a',N),('poll',N),('poll',N),('finish','a'),('finish','a')]), [[['start','a'],['start','b'],['finish','a']],[],['b']])\ncheck('3', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('poll',N+5)]), [[['start','a']],[],['a']])\ncheck('4', solve([('schedule','a',1),('schedule','b',2),('cancel','a'),('schedule','a',3),('poll',5)]), [[['start','b']],[],['b']])\ncheck('5', solve([('schedule','a',1),('schedule','b',1),('poll',1),('cancel','a'),('finish','a')]), [[['start','a'],['start','b']],[],['b']])\ncheck('6', solve([('schedule','a',1),('poll',1),('schedule','a',3),('poll',3),('finish','z')]), [[['start','a']],[],['a']])\ncheck('7', solve([('schedule','z',1),('schedule','a',2),('poll',3)]), [[['start','z'],['start','a']],[],['a','z']])\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"},"fixed":{"sha256":"3a7527174aaf8aa72ac918b252ef08a54dbbcd638d1685afc44c535cb9e9739f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    queued={}; running=set(); cancelled=set(); out=[]\n    for e in events:\n        if e[0]=='schedule':\n            if e[1] in cancelled: continue\n            if e[1] in running: continue\n            queued[e[1]]=e[2]\n        elif e[0]=='cancel':\n            cancelled.add(e[1])\n            queued.pop(e[1],None)\n            running.discard(e[1])\n        elif e[0]=='poll':\n            ready=sorted((due,k) for k,due in queued.items() if due<=e[1])\n            for due,k in ready:\n                queued.pop(k)\n                running.add(k)\n                out.append(['start',k])\n        elif e[0]=='finish':\n            if e[1] not in running: continue\n            running.remove(e[1])\n            out.append(['finish',e[1]])\n    return [out,sorted(queued),sorted(running)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('cancel','a'),('poll',N+5)]), [[],[],[]])\ncheck('1', solve([]), [[],[],[]])\ncheck('2', solve([('schedule','b',N),('schedule','a',N),('poll',N),('poll',N),('finish','a'),('finish','a')]), [[['start','a'],['start','b'],['finish','a']],[],['b']])\ncheck('3', solve([('schedule','a',1),('schedule','a',N+5),('poll',1),('poll',N+5)]), [[['start','a']],[],['a']])\ncheck('4', solve([('schedule','a',1),('schedule','b',2),('cancel','a'),('schedule','a',3),('poll',5)]), [[['start','b']],[],['b']])\ncheck('5', solve([('schedule','a',1),('schedule','b',1),('poll',1),('cancel','a'),('finish','a')]), [[['start','a'],['start','b']],[],['b']])\ncheck('6', solve([('schedule','a',1),('poll',1),('schedule','a',3),('poll',3),('finish','z')]), [[['start','a']],[],['a']])\ncheck('7', solve([('schedule','z',1),('schedule','a',2),('poll',3)]), [[['start','z'],['start','a']],[],['a','z']])\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":"Stipulated bounded simulator, not a complete HTTP implementation or a standards 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-http_retries-scheduled-cancellation-cancel-queued","generated_at":"2026-09-29T14:41:48.373414+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline deterministic model of HTTP request retries.","repair":"Restore the specified transition queued.pop(e[1],None).","root_cause":"Cancel queued violates retry transition semantics","sha256":"eee3b356b5803e72672f1d26f73c49c86fe73fcbebafa52b9be644f31e20b8d8","title":"Cancellation of queued retries: Cancel queued violates retry transition semantics · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.311,"exit_code":1,"observations":[{"actual":[[],[],[]],"check":"0","expected":[[],[],[]],"passed":true},{"actual":[[],[],[]],"check":"1","expected":[[],[],[]],"passed":true},{"actual":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"check":"2","expected":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"3","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[],[],[]],"check":"4","expected":[[["start","b"]],[],["b"]],"passed":false},{"actual":[[["start","a"],["start","b"]],[],["b"]],"check":"5","expected":[[["start","a"],["start","b"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"6","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[["start","z"],["start","a"]],[],["a","z"]],"check":"7","expected":[[["start","z"],["start","a"]],[],["a","z"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[], [], []], \"expected\": [[], [], []], \"passed\": true}, {\"check\": \"1\", \"actual\": [[], [], []], \"expected\": [[], [], []], \"passed\": true}, {\"check\": \"2\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"4\", \"actual\": [[], [], []], \"expected\": [[[\"start\", \"b\"]], [], [\"b\"]], \"passed\": false}, {\"check\": \"5\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"6\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"7\", \"actual\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"expected\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.71,"exit_code":1,"observations":[{"actual":[[["start","a"]],[],["a"]],"check":"0","expected":[[],[],[]],"passed":false},{"actual":[[],[],[]],"check":"1","expected":[[],[],[]],"passed":true},{"actual":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"check":"2","expected":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"3","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[["start","a"],["start","b"]],[],["a","b"]],"check":"4","expected":[[["start","b"]],[],["b"]],"passed":false},{"actual":[[["start","a"],["start","b"]],[],["b"]],"check":"5","expected":[[["start","a"],["start","b"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"6","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[["start","z"],["start","a"]],[],["a","z"]],"check":"7","expected":[[["start","z"],["start","a"]],[],["a","z"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[], [], []], \"passed\": false}, {\"check\": \"1\", \"actual\": [[], [], []], \"expected\": [[], [], []], \"passed\": true}, {\"check\": \"2\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"4\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"a\", \"b\"]], \"expected\": [[[\"start\", \"b\"]], [], [\"b\"]], \"passed\": false}, {\"check\": \"5\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"6\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"7\", \"actual\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"expected\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.456,"exit_code":0,"observations":[{"actual":[[],[],[]],"check":"0","expected":[[],[],[]],"passed":true},{"actual":[[],[],[]],"check":"1","expected":[[],[],[]],"passed":true},{"actual":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"check":"2","expected":[[["start","a"],["start","b"],["finish","a"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"3","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[["start","b"]],[],["b"]],"check":"4","expected":[[["start","b"]],[],["b"]],"passed":true},{"actual":[[["start","a"],["start","b"]],[],["b"]],"check":"5","expected":[[["start","a"],["start","b"]],[],["b"]],"passed":true},{"actual":[[["start","a"]],[],["a"]],"check":"6","expected":[[["start","a"]],[],["a"]],"passed":true},{"actual":[[["start","z"],["start","a"]],[],["a","z"]],"check":"7","expected":[[["start","z"],["start","a"]],[],["a","z"]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[], [], []], \"expected\": [[], [], []], \"passed\": true}, {\"check\": \"1\", \"actual\": [[], [], []], \"expected\": [[], [], []], \"passed\": true}, {\"check\": \"2\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"], [\"finish\", \"a\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"4\", \"actual\": [[[\"start\", \"b\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"b\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"5\", \"actual\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"expected\": [[[\"start\", \"a\"], [\"start\", \"b\"]], [], [\"b\"]], \"passed\": true}, {\"check\": \"6\", \"actual\": [[[\"start\", \"a\"]], [], [\"a\"]], \"expected\": [[[\"start\", \"a\"]], [], [\"a\"]], \"passed\": true}, {\"check\": \"7\", \"actual\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"expected\": [[[\"start\", \"z\"], [\"start\", \"a\"]], [], [\"a\", \"z\"]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}