{"record":{"id":"942db806178098c6","repo":"XTLS/Xray-core","slug":"maxincomingstreams-must-be-at-least-8","errorCode":null,"errorMessage":"MaxIncomingStreams must be at least 8","messagePattern":"MaxIncomingStreams must be at least 8","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"infra/conf/transport_internet.go","lineNumber":279,"sourceCode":"\t\t\t\treturn nil, errors.New(\"InitStreamReceiveWindow must be at least 16384\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.MaxStreamReceiveWindow > 0 && c.FinalMask.QuicParams.MaxStreamReceiveWindow < 16384 {\n\t\t\t\treturn nil, errors.New(\"MaxStreamReceiveWindow must be at least 16384\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.InitConnectionReceiveWindow > 0 && c.FinalMask.QuicParams.InitConnectionReceiveWindow < 16384 {\n\t\t\t\treturn nil, errors.New(\"InitConnectionReceiveWindow must be at least 16384\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.MaxConnectionReceiveWindow > 0 && c.FinalMask.QuicParams.MaxConnectionReceiveWindow < 16384 {\n\t\t\t\treturn nil, errors.New(\"MaxConnectionReceiveWindow must be at least 16384\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.MaxIdleTimeout != 0 && (c.FinalMask.QuicParams.MaxIdleTimeout < 4 || c.FinalMask.QuicParams.MaxIdleTimeout > 120) {\n\t\t\t\treturn nil, errors.New(\"MaxIdleTimeout must be between 4 and 120\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.KeepAlivePeriod != 0 && (c.FinalMask.QuicParams.KeepAlivePeriod < 2 || c.FinalMask.QuicParams.KeepAlivePeriod > 60) {\n\t\t\t\treturn nil, errors.New(\"KeepAlivePeriod must be between 2 and 60\")\n\t\t\t}\n\t\t\tif c.FinalMask.QuicParams.MaxIncomingStreams != 0 && c.FinalMask.QuicParams.MaxIncomingStreams < 8 {\n\t\t\t\treturn nil, errors.New(\"MaxIncomingStreams must be at least 8\")\n\t\t\t}\n\n\t\t\tif c.FinalMask.QuicParams.Debug {\n\t\t\t\tos.Setenv(\"HYSTERIA_BBR_DEBUG\", \"true\")\n\t\t\t\tos.Setenv(\"HYSTERIA_BRUTAL_DEBUG\", \"true\")\n\t\t\t}\n\n\t\t\tconfig.QuicParams = &internet.QuicParams{\n\t\t\t\tCongestion: c.FinalMask.QuicParams.Congestion,\n\t\t\t\tBbrProfile: profile,\n\t\t\t\tBrutalUp:   up,\n\t\t\t\tBrutalDown: down,\n\t\t\t\tUdpHop: &internet.UdpHop{\n\t\t\t\t\tPorts:       c.FinalMask.QuicParams.UdpHop.PortList.Build().Ports(),\n\t\t\t\t\tIntervalMin: int64(c.FinalMask.QuicParams.UdpHop.Interval.From),\n\t\t\t\t\tIntervalMax: int64(c.FinalMask.QuicParams.UdpHop.Interval.To),\n\t\t\t\t},\n\t\t\t\tInitStreamReceiveWindow: c.FinalMask.QuicParams.InitStreamReceiveWindow,","sourceCodeStart":261,"sourceCodeEnd":297,"githubUrl":"https://github.com/XTLS/Xray-core/blob/7d214f8b094f75322fa3990f8aadad1c912f24f5/infra/conf/transport_internet.go#L261-L297","documentation":"Floor check on finalMask.quicParams.maxIncomingStreams: if set (non-zero) it must be at least 8. Lower limits would make the QUIC endpoint reject nearly all concurrent stream opens. 0 keeps the default. This is the final numeric validation before the QuicParams protobuf is assembled.","triggerScenarios":"\"quicParams\": { \"maxIncomingStreams\": 4 }.","commonSituations":"Trying to limit concurrency to an extremely small number; confusing streams with connections; using a placeholder value of 1 during testing.","solutions":["Set maxIncomingStreams >= 8 (e.g. 32, 64, or higher for busy servers).","Or omit the field for the default.","If limiting concurrency is the goal, use a value at or above 8 and enforce policy elsewhere."],"exampleFix":"// before\n\"quicParams\": { \"maxIncomingStreams\": 4 }\n// after\n\"quicParams\": { \"maxIncomingStreams\": 64 }","handlingStrategy":"validation","validationCode":"func maxIncomingStreamsOK(qp map[string]any) bool {\n    v, ok := qp[\"maxIncomingStreams\"].(float64)\n    return !ok || v == 0 || v >= 8\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Never set maxIncomingStreams below 8; use 0 for the default.","Size it above expected concurrent streams (multiplexed connections need many).","Enforce concurrency limits in routing policy, not by starving QUIC streams."],"tags":["go","xray","config","quic","streams","validation"],"backgroundTag":null,"analyzedSha":"7d214f8b094f75322fa3990f8aadad1c912f24f5","analyzedAt":"2026-08-15T14:26:24.325Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}