{"abstract":"Stream identity violates retry transition semantics","category":"HTTP retries","checks":7,"contract":"open(stream ID,replayable) records a live stream. goaway(last ID) monotonically lowers the accepted stream boundary. fail(id) retries only replayable streams above the known boundary (known unprocessed), otherwise reports ambiguous; unknown/already-finished streams are ignored. succeed closes a stream. New streams after GOAWAY are blocked. reconnect resets connection boundary and stream IDs while retaining decision history.","contract_signature":"events","evaluation_group":"s3-http_retries-goaway-retry","failed_approach":"The attempted repair changes the faulty site to streams[e[1]//2]=[e[2],True] but still violates a regression oracle.","family":"s3-http_retries-goaway-retry-stream-identity","id":"FA-29736","implementations":{"attempt":{"sha256":"66834a3c64292d31428f06f822940f931efdc3766d1abaedc4beb1ff3e6a7211","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    streams={}; boundary=None; out=[]\n    for e in events:\n        if e[0]=='open':\n            if boundary is not None: out.append('draining'); continue\n            if e[1] in streams: out.append('duplicate'); continue\n            streams[e[1]//2]=[e[2],True]\n        elif e[0]=='goaway':\n            boundary=e[1] if boundary is None else min(boundary,e[1])\n        elif e[0]=='succeed':\n            if e[1] in streams: streams[e[1]][1]=False\n        elif e[0]=='fail':\n            if e[1] not in streams: out.append('unknown'); continue\n            replayable,active=streams[e[1]]\n            if not active: out.append('finished'); continue\n            streams[e[1]][1]=False\n            if boundary is not None and e[1]>boundary:\n                out.append('retry' if replayable else 'unreplayable')\n            else: out.append('ambiguous')\n        elif e[0]=='reconnect':\n            boundary=None\n            streams={}\n    return [out,boundary]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([]), [[],None])\ncheck('1', solve([('open',1,True),('open',1,False),('fail',1),('fail',1),('fail',9)]), [['duplicate','ambiguous','finished','unknown'],None])\ncheck('2', solve([('open',1,True),('open',3,True),('open',5,False),('goaway',3),('fail',1),('fail',3),('fail',5)]), [['ambiguous','ambiguous','unreplayable'],3])\ncheck('3', solve([('open',3,True),('goaway',1),('goaway',5),('fail',3),('open',7,True)]), [['retry','draining'],1])\ncheck('4', solve([('open',1,True),('goaway',0),('open',3,True),('succeed',1),('fail',1)]), [['draining','finished'],0])\ncheck('5', solve([('open',1,True),('goaway',0),('reconnect',),('open',1,False),('goaway',0),('fail',1)]), [['unreplayable'],0])\ncheck('6', solve([('open',N+10,True),('goaway',N+9),('fail',N+10),('fail',N+10)]), [['retry','finished'],N+9])\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":"43373eebd2196171044bc846002773fb6bc868d9281d7876cc44160c4baf9ac4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events):\n    streams={}; boundary=None; out=[]\n    for e in events:\n        if e[0]=='open':\n            if boundary is not None: out.append('draining'); continue\n            if e[1] in streams: out.append('duplicate'); continue\n            streams[0]=[e[2],True]\n        elif e[0]=='goaway':\n            boundary=e[1] if boundary is None else min(boundary,e[1])\n        elif e[0]=='succeed':\n            if e[1] in streams: streams[e[1]][1]=False\n        elif e[0]=='fail':\n            if e[1] not in streams: out.append('unknown'); continue\n            replayable,active=streams[e[1]]\n            if not active: out.append('finished'); continue\n            streams[e[1]][1]=False\n            if boundary is not None and e[1]>boundary:\n                out.append('retry' if replayable else 'unreplayable')\n            else: out.append('ambiguous')\n        elif e[0]=='reconnect':\n            boundary=None\n            streams={}\n    return [out,boundary]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([]), [[],None])\ncheck('1', solve([('open',1,True),('open',1,False),('fail',1),('fail',1),('fail',9)]), [['duplicate','ambiguous','finished','unknown'],None])\ncheck('2', solve([('open',1,True),('open',3,True),('open',5,False),('goaway',3),('fail',1),('fail',3),('fail',5)]), [['ambiguous','ambiguous','unreplayable'],3])\ncheck('3', solve([('open',3,True),('goaway',1),('goaway',5),('fail',3),('open',7,True)]), [['retry','draining'],1])\ncheck('4', solve([('open',1,True),('goaway',0),('open',3,True),('succeed',1),('fail',1)]), [['draining','finished'],0])\ncheck('5', solve([('open',1,True),('goaway',0),('reconnect',),('open',1,False),('goaway',0),('fail',1)]), [['unreplayable'],0])\ncheck('6', solve([('open',N+10,True),('goaway',N+9),('fail',N+10),('fail',N+10)]), [['retry','finished'],N+9])\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-goaway-retry-stream-identity","generated_at":"2026-09-29T14:41:46.679525+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline deterministic model of HTTP request retries.","root_cause":"Stream identity violates retry transition semantics","sha256":"19d94bacb77994a227760ea507f3a0237983f2ebacbc9ad296f69cd8b2031286","title":"GOAWAY retry admission: Stream identity violates retry transition semantics · 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":40.737,"exit_code":1,"observations":[{"actual":[[],null],"check":"0","expected":[[],null],"passed":true},{"actual":[["unknown","unknown","unknown"],null],"check":"1","expected":[["duplicate","ambiguous","finished","unknown"],null],"passed":false},{"actual":[["ambiguous","unknown","unknown"],3],"check":"2","expected":[["ambiguous","ambiguous","unreplayable"],3],"passed":false},{"actual":[["unknown","draining"],1],"check":"3","expected":[["retry","draining"],1],"passed":false},{"actual":[["draining","unknown"],0],"check":"4","expected":[["draining","finished"],0],"passed":false},{"actual":[["unknown"],0],"check":"5","expected":[["unreplayable"],0],"passed":false},{"actual":[["unknown","unknown"],10],"check":"6","expected":[["retry","finished"],10],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[], null], \"expected\": [[], null], \"passed\": true}, {\"check\": \"1\", \"actual\": [[\"unknown\", \"unknown\", \"unknown\"], null], \"expected\": [[\"duplicate\", \"ambiguous\", \"finished\", \"unknown\"], null], \"passed\": false}, {\"check\": \"2\", \"actual\": [[\"ambiguous\", \"unknown\", \"unknown\"], 3], \"expected\": [[\"ambiguous\", \"ambiguous\", \"unreplayable\"], 3], \"passed\": false}, {\"check\": \"3\", \"actual\": [[\"unknown\", \"draining\"], 1], \"expected\": [[\"retry\", \"draining\"], 1], \"passed\": false}, {\"check\": \"4\", \"actual\": [[\"draining\", \"unknown\"], 0], \"expected\": [[\"draining\", \"finished\"], 0], \"passed\": false}, {\"check\": \"5\", \"actual\": [[\"unknown\"], 0], \"expected\": [[\"unreplayable\"], 0], \"passed\": false}, {\"check\": \"6\", \"actual\": [[\"unknown\", \"unknown\"], 10], \"expected\": [[\"retry\", \"finished\"], 10], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.099,"exit_code":1,"observations":[{"actual":[[],null],"check":"0","expected":[[],null],"passed":true},{"actual":[["unknown","unknown","unknown"],null],"check":"1","expected":[["duplicate","ambiguous","finished","unknown"],null],"passed":false},{"actual":[["unknown","unknown","unknown"],3],"check":"2","expected":[["ambiguous","ambiguous","unreplayable"],3],"passed":false},{"actual":[["unknown","draining"],1],"check":"3","expected":[["retry","draining"],1],"passed":false},{"actual":[["draining","unknown"],0],"check":"4","expected":[["draining","finished"],0],"passed":false},{"actual":[["unknown"],0],"check":"5","expected":[["unreplayable"],0],"passed":false},{"actual":[["unknown","unknown"],10],"check":"6","expected":[["retry","finished"],10],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[], null], \"expected\": [[], null], \"passed\": true}, {\"check\": \"1\", \"actual\": [[\"unknown\", \"unknown\", \"unknown\"], null], \"expected\": [[\"duplicate\", \"ambiguous\", \"finished\", \"unknown\"], null], \"passed\": false}, {\"check\": \"2\", \"actual\": [[\"unknown\", \"unknown\", \"unknown\"], 3], \"expected\": [[\"ambiguous\", \"ambiguous\", \"unreplayable\"], 3], \"passed\": false}, {\"check\": \"3\", \"actual\": [[\"unknown\", \"draining\"], 1], \"expected\": [[\"retry\", \"draining\"], 1], \"passed\": false}, {\"check\": \"4\", \"actual\": [[\"draining\", \"unknown\"], 0], \"expected\": [[\"draining\", \"finished\"], 0], \"passed\": false}, {\"check\": \"5\", \"actual\": [[\"unknown\"], 0], \"expected\": [[\"unreplayable\"], 0], \"passed\": false}, {\"check\": \"6\", \"actual\": [[\"unknown\", \"unknown\"], 10], \"expected\": [[\"retry\", \"finished\"], 10], \"passed\": false}], \"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."}}