FlowMonitor don't show statistics, but PyViz and trace files shows it

Question

There is a simple model of data transfer.

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

#include <iostream>
#include <fstream> 
#include <string>  
#include <cassert> 

#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/csma-module.h"   
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"  
#include "ns3/ipv4-global-routing-helper.h"
#include "ns3/flow-monitor-module.h"       

//
// Network Topology
//                         
//    n0 (source)           
//    |
//    |
//    |
//    |   
//    |
//    -------------------n1      n2        n3--------n4  n5   n6 (sink)
//    point-to-point      |      |         |         |   |    |
//     10.1.1.0           ==================         ==========
//                        LAN 10.1.2.0              LAN 10.1.3.0  
//                      (CSMA subnet 1)           (CSMA subnet 2)    

using namespace ns3;

int main (int argc, char *argv[])
{                       
        Config::SetDefault ( "ns3::OnOffApplication::PacketSize", UintegerValue ( 700 ) );
        Config::SetDefault ( "ns3::OnOffApplication::DataRate", StringValue ( "1000000" ) );

        CommandLine cmd;
        cmd.Parse(argc,argv);

        NodeContainer p2pNodes;
        p2pNodes.Create(2);   

        NodeContainer csmaNodesSubNetOne;
        csmaNodesSubNetOne.Add(p2pNodes.Get(1));
        csmaNodesSubNetOne.Create(2);        

        NodeContainer csmaNodesSubNetTwo;
        csmaNodesSubNetTwo.Add(csmaNodesSubNetOne.Get(2));
        csmaNodesSubNetTwo.Create(2);

        PointToPointHelper pointToPoint;
        pointToPoint.SetDeviceAttribute("DataRate", StringValue ("100Mbps"));
        pointToPoint.SetDeviceAttribute("Mtu", UintegerValue(1000));        
        pointToPoint.SetChannelAttribute("Delay", TimeValue (NanoSeconds (6560)));    

        NetDeviceContainer p2pDevices;
        p2pDevices = pointToPoint.Install(p2pNodes);

        CsmaHelper csmaHelperSubNetOne;
        csmaHelperSubNetOne.SetChannelAttribute("DataRate", StringValue ("100Mbps"));
        csmaHelperSubNetOne.SetChannelAttribute("Delay", TimeValue (NanoSeconds (6560)));
        csmaHelperSubNetOne.SetDeviceAttribute("Mtu", UintegerValue(1000));               

        NetDeviceContainer csmaDevicesSubNetOne;
        csmaDevicesSubNetOne = csmaHelperSubNetOne.Install(csmaNodesSubNetOne);

        CsmaHelper csmaHelperSubNetTwo;
        csmaHelperSubNetTwo.SetChannelAttribute("DataRate", StringValue ("100Mbps"));
        csmaHelperSubNetTwo.SetChannelAttribute("Delay", TimeValue (NanoSeconds (6560)));
        csmaHelperSubNetTwo.SetDeviceAttribute("Mtu", UintegerValue(1000));               

        NetDeviceContainer csmaDevicesSubNetTwo;
        csmaDevicesSubNetTwo = csmaHelperSubNetTwo.Install(csmaNodesSubNetTwo);

        InternetStackHelper internetStackHelper;
        internetStackHelper.Install(p2pNodes.Get(0));

        internetStackHelper.Install(csmaNodesSubNetOne.Get(0));
        internetStackHelper.Install(csmaNodesSubNetOne.Get(1));

        internetStackHelper.Install(csmaNodesSubNetTwo.Get(0));
        internetStackHelper.Install(csmaNodesSubNetTwo.Get(1));
        internetStackHelper.Install(csmaNodesSubNetTwo.Get(2));

        Ipv4AddressHelper address;
        address.SetBase ("10.1.1.0", "255.255.255.0");
        Ipv4InterfaceContainer p2pInterfaces;
        p2pInterfaces = address.Assign (p2pDevices);

        address.SetBase ("10.1.2.0", "255.255.255.0");
        Ipv4InterfaceContainer csmaInterfacesSubNetOne;
        csmaInterfacesSubNetOne = address.Assign (csmaDevicesSubNetOne);

        address.SetBase ("10.1.3.0", "255.255.255.0");
        Ipv4InterfaceContainer csmaInterfacesSubNetTwo;
        csmaInterfacesSubNetTwo = address.Assign (csmaDevicesSubNetTwo);

        InetSocketAddress dst = InetSocketAddress ( csmaInterfacesSubNetTwo.GetAddress ( 2 ) );
        OnOffHelper onoff = OnOffHelper ( "ns3::Ipv4RawSocketFactory", dst );

        ApplicationContainer apps = onoff.Install( p2pNodes.Get(0) );
        apps.Start ( Seconds (2.0) );
        apps.Stop ( Seconds (10.0) );

        PacketSinkHelper sink = PacketSinkHelper ("ns3::Ipv4RawSocketFactory", dst);
        apps = sink.Install (csmaNodesSubNetTwo.Get( 2 ));
        apps.Start (Seconds (1.0));
        apps.Stop (Seconds (10.0));

        Ipv4GlobalRoutingHelper::PopulateRoutingTables( );  

        csmaHelperSubNetTwo.EnablePcap ("sniffer", csmaDevicesSubNetTwo.Get (1), true);

        AsciiTraceHelper ascii;
        csmaHelperSubNetTwo.EnableAsciiAll( ascii.CreateFileStream( "receiver-trace.tr" ) );

        Simulator::Stop (Seconds (11));

        FlowMonitorHelper flowmon;
        Ptr<FlowMonitor> monitor = flowmon.InstallAll();
        monitor = flowmon.GetMonitor();

        Simulator::Run ();

        monitor->CheckForLostPackets ();
        Ptr<Ipv4FlowClassifier> classifier = DynamicCast<Ipv4FlowClassifier> (flowmon.GetClassifier ());
        std::map<FlowId, FlowMonitor::FlowStats> stats = monitor->GetFlowStats ();
        for(std::map<FlowId, FlowMonitor::FlowStats>::const_iterator i = stats.begin (); i != stats.end (); ++i)
        {
                Ipv4FlowClassifier::FiveTuple t = classifier->FindFlow (i->first);

                std::cout << "  Flow " << i->first << " (" << t.sourceAddress << " -> " << t.destinationAddress << ")\n";
                std::cout << "  Tx Bytes:   " << i->second.txBytes << "\n";
                std::cout << "  Rx Bytes:   " << i->second.rxBytes << "\n";
                std::cout << "  Throughput: " << i->second.rxBytes * 8.0 / 10.0 / 1024 / 1024  << " Mbps\n";
        }

        monitor->SerializeToXmlFile("serialize-stat.flowmon", true, true);

        Simulator::Destroy();
        return 0;
}

I can build and run this model and see the results in PyViz.

Also in PyViz I see statistics for the node receiver.

The trace file contains data. Here's one line from the big trace file.

...
r 3.00585 /NodeList/5/DeviceList/0/$ns3::CsmaNetDevice/MacRx ns3::EthernetHeader ( length/type=0x800, source=00:00:00:00:00:06, destination=00:00:00:00:00:08) ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 0 protocol 0 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700) ns3::EthernetTrailer (fcs=0)
...

I can parse this trace file by using AWK.

[root@localhost ns-3.16]# awk '{print $2 ", " $28}' receiver-trace.tr >grab.dat
[root@localhost ns-3.16]# cat grab.dat
...
3.00578, 720
3.00578, 720
3.00585, 720
3.01126, 720
3.01126, 720
3.01133, 720
3.01133, 720
3.01133, 720
3.0114, 720
3.01686, 720
3.01686, 720
3.01693, 720
3.01693, 720
3.01693, 720
3.017, 720
3.02246, 720
...

But FlowMonitor nothing shows and the xml file has no useful information.

<?xml version="1.0" ?>
<FlowMonitor>
  <FlowStats>
  </FlowStats>
  <Ipv4FlowClassifier>
  </Ipv4FlowClassifier>
  <FlowProbes>
    <FlowProbe index="0">
    </FlowProbe>
    <FlowProbe index="1">
    </FlowProbe>
    <FlowProbe index="2">
    </FlowProbe>
    <FlowProbe index="3">
    </FlowProbe>
    <FlowProbe index="4">
    </FlowProbe>
    <FlowProbe index="5">
    </FlowProbe>
  </FlowProbes>
</FlowMonitor>

In what could be the reason?

Answer 1

As an alternative, may be used callbacks.

...
static void PrintRx ( Ptr< const Packet > p, const Address &ad )
{
   std::string traceLine = boost::lexical_cast< string >( *p );
   std::cout << Simulator::Now().GetSeconds () << " " << traceLine << std::endl; 
}

int main (int argc, char *argv[])
{                       
...
Config::ConnectWithoutContext ("/NodeList/*/ApplicationList/0/$ns3::PacketSink/Rx", MakeCallback (&PrintRx));
Packet::EnablePrinting ();
...

As shown below possible to see the contents of received packets and then create own instrument of statistical analysis.

...                                                               
19.881 ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 3192 protocol 2 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700)
19.8866 ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 3193 protocol 2 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700)
19.8922 ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 3194 protocol 2 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700)
19.8978 ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 3195 protocol 2 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700)
19.9034 ns3::Ipv4Header (tos 0x0 DSCP Default ECN Not-ECT ttl 62 id 3196 protocol 2 offset (bytes) 0 flags [none] length: 720 10.1.1.1 > 10.1.3.3) Payload (size=700)
...