fix: prevent QUIC heartbeat stalls and isolate TCP retransmission counters [CI] [SKIP TESTS]

backend/shared/tests/MoShiro.Measurement.Tests/MeasurementTests.cs

@@ -203,7 +203,7 @@ public sealed class MeasurementTests
         var builder = new StreamBuilder(spec);
         foreach ((long ts, long side, long retrans) in rows)
         {
-            builder.Add(ts, side, 40_000, 5_000, 10, retrans, 100, 1_000);
+            builder.Add(ts, side, 40_000, 5_000, 10, retrans, 100, 1_000, null);
         }
 
         return builder.Build();
@@ -216,8 +216,8 @@ public sealed class MeasurementTests
         Assert.Equal(info.Columns.Count, info.ColumnsOf(Side.Agent).Count); // each side owns every column
         var agent = new RowStore(info, Side.Agent, 64);
         var recorder = new Source { Stores = { ["tcp_info"] = agent } };
-        agent.SetRow(agent.Append(), [500, 1, 40_000, 5_000, 10, 7, 100, 1_000]);
-        agent.SetRow(agent.Append(), [600, 1, 40_000, 5_000, 10, 8, 120, 1_100]);
+        agent.SetRow(agent.Append(), [500, 1, 40_000, 5_000, 10, 7, 100, 1_000, 1]);
+        agent.SetRow(agent.Append(), [600, 1, 40_000, 5_000, 10, 8, 120, 1_100, 1]);
 
         var msg = EchoFragment((0, 1000, 3000));
         var fragment = new RawChunk(msg.Header, [msg.Streams[0], InfoRows(info, (100, 0, 1))]);
@@ -227,6 +227,8 @@ public sealed class MeasurementTests
         Assert.Equal(3, merged.Count);
         Assert.Equal([0L, 1L, 1L], merged.Find("side")!.Values);
         Assert.Equal([1L, 7L, 8L], merged.Find("retrans_total")!.Values);
+        Assert.False(merged.Find("conn")!.IsValid(0));
+        Assert.Equal(1, merged.Find("conn")!.Values[1]);
 
         // The agent's rows were consumed: the next chunk carries only the probe's own rows
         IReadOnlyList<RawStream> second = FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, recorder).Value;
@@ -238,7 +240,7 @@ public sealed class MeasurementTests
     {
         StreamSpec info = Kinds.TcpEcho.FindStream("tcp_info")!;
         var agent = new RowStore(info, Side.Agent, 64);
-        agent.SetRow(agent.Append(), [500, 1, 40_000, 5_000, 10, 7, 100, 1_000]);
+        agent.SetRow(agent.Append(), [500, 1, 40_000, 5_000, 10, 7, 100, 1_000, 1]);
 
         // A probe on a platform without kernel sampling sends the echo rows only
         RawChunk fragment = EchoFragment((0, 1000, 3000));
@@ -248,6 +250,18 @@ public sealed class MeasurementTests
         Assert.Equal(7, rows.Find("retrans_total")!.Values[0]);
     }
 
+    [Fact]
+    public void FragmentMerger_LegacyTcpSamples_KeepConnectionIdentityUnknown()
+    {
+        StreamSpec info = Kinds.TcpEcho.FindStream("tcp_info")!;
+        RawStream sample = InfoRows(info, (100, 0, 1));
+        var legacy = new RawStream(sample.Name, sample.Count, sample.Columns.Where(c => c.Name != "conn").ToArray());
+        var fragment = new RawChunk(new RawChunkHeader { Kind = "tcp_echo" }, [legacy]);
+        RawStream merged = Assert.Single(FragmentMerger.Merge(Kinds.TcpEcho, fragment, 1, new Source()).Value);
+        Assert.False(merged.Find("conn")!.IsValid(0));
+        Assert.Equal(1, merged.Find("retrans_total")!.Values[0]);
+    }
+
     [Fact]
     public void TcpInfo_OnLinux_ReadsTheKernelCountersOfALiveConnection()
     {