iOS 奇怪日志 NETAWDManager

Question

使用 iOS 9，我在我的 iPhone 控制台中看到奇怪的日志

当应用程序连接到远程服务时会出现这些日志，也许当连接速度很慢时，我使用 NSURLSession。 有人知道这个日志的含义，我应该关心这个吗：

-[NETAWDManager reportStats:metricID:] server 0x13cd19d70, container 0x13ce9dfe0, metrid 2686983, successfully reported:
<AWDLibnetcoreTCPConnectionReport: 0x13ce7af10> {
    cellularFallbackReport =     {
        dataUsageSnapshotsAtNetworkEvents =         (
                        {
                bytesIn = 0;
                bytesOut = 410;
            }
        );
        "fallbackTimer_msecs" = 0;
        fellback = 0;
        networkEvents =         (
            "NETWORK_EVENT_DATA_STALL_AT_APP_LAYER"
        );
        "timeToNetworkEvents_msecs" =         (
            3325
        );
    };
    clientIdentifier = "com.mydomain.myapp";
    connectionStatisticsReport =     {
        DNSAnswersCached = 1;
        "DNSResolvedTime_msecs" = 3;
        RTTvariance = 169;
        "appDataStallTimer_msecs" = 3;
        appReportingDataStallCount = 1;
        "bestRTT_msecs" = 359;
        betterRouteEventCount = 0;
        bytesDuplicate = 0;
        bytesIn = 37000;
        bytesOut = 410;
        bytesOutOfOrder = 0;
        bytesRetransmitted = 0;
        cellularFallback = 0;
        cellularRRCConnected = 0;
        connected = 1;
        connectedInterfaceType = "INTERFACE_TYPE_WIFI";
        "connectionEstablishmentTime_msecs" = 308;
        connectionReuseCount = 0;
        "currentRTT_msecs" = 79;
        "flowDuration_msecs" = 30750;
        interfaceType = "INTERFACE_TYPE_WIFI";
        kernelReportedStalls = 0;
        kernelReportingConnectionStalled = 0;
        kernelReportingReadStalled = 0;
        kernelReportingWriteStalled = 0;
        packetsDuplicate = 0;
        packetsIn = 26;
        packetsOut = 1;
        packetsOutOfOrder = 0;
        packetsRetransmitted = 0;
        "smoothedRTT_msecs" = 275;
        synRetransmissionCount = 0;
        tcpFastOpen = 0;
        "timeToConnectionEstablishment_msecs" = 315;
        "timeToConnectionStart_msecs" = 7;
        "timeToDNSResolved_msecs" = 7;
        "timeToDNSStart_msecs" = 4;
        trafficClass = 0;
    };
    delegated = 0;
    reportReason = "REPORT_REASON_DATA_STALL_AT_APP_LAYER";
}

Answer 1

根据标识符cellularFallbackReport，这条消息可能与WiFi Assist相关。这是 iOS 9 中的一项新功能，可检测慢速 WiFi 连接并自动回退到手机的蜂窝无线电。

这与您的观察结果一致，即当您的连接速度较慢时会出现日志消息。

如果您能够可靠地重现该消息，请尝试在设置中禁用 WiFi Assist 并查看它是否消失：

如果真的是这样，你应该关心它吗？可能不是。这些消息表明 iOS 系统正在代表您的应用自动处理网络问题，您对此无能为力。