test(loadharness): target-scale load harness for WP-4 / register #25 + row 50

Standalone console harness under tests/ZB.MOM.WW.ScadaBridge.LoadHarness plus a scaled-down Category=Performance smoke [Fact] in PerformanceTests. Deliberately an Exe rather than an xunit suite: the Performance trait enables a filter but does not exclude by default, so a 20-minute test would run on every 'dotnet test' of the slnx. What is real: per-site ActorSystem + LocalDb SQLite file, the real DCL (DataConnectionManagerActor/DataConnectionActor over a SimulatedDataConnection registered through the documented DataConnectionFactory.RegisterAdapter seam), real InstanceActors fed real TagValueUpdates, the real SiteStreamManager, real StreamRelayActor + production-capacity bounded DropOldest channel, real StoreAndForwardService/Storage, real SiteHealthCollector + CentralHealthAggregator. Only the socket hops are stood in for. Measures: end-to-end tag update latency (the emit instant rides TagValueUpdate.Timestamp verbatim to the subscriber), instance ramp, memory growth/CPU over a steady-state window, health report and debug view latency under load, S&F concurrent buffering + drain throughput, and slow-subscriber isolation.
2026-08-15 02:23:04 -04:00
parent 986e6e7ad5
commit 20f6b0b969
17 changed files with 2419 additions and 0 deletions
@@ -0,0 +1,84 @@
+using ZB.MOM.WW.ScadaBridge.LoadHarness;
+
+namespace ZB.MOM.WW.ScadaBridge.PerformanceTests.TargetScale;
+
+/// <summary>
+/// Keeps the target-scale load harness (deferred-work register #25 / Phase-8 WP-4)
+/// honest at CI scale.
+///
+/// <para>
+/// The full protocol — 10 sites x 500 instances x 75 tags sustained for 20 minutes —
+/// deliberately lives in the standalone <c>ZB.MOM.WW.ScadaBridge.LoadHarness</c>
+/// executable, NOT here: perf tests in this project run as part of an ordinary
+/// <c>dotnet test ZB.MOM.WW.ScadaBridge.slnx</c> (the <c>Category=Performance</c>
+/// trait enables a filter, it does not exclude by default), and a 20-minute test
+/// would be intolerable there. What this test protects is that the harness still
+/// compiles, wires up, and produces coherent measurements — so #25's evidence can be
+/// regenerated on demand rather than bit-rotting.
+/// </para>
+/// <para>
+/// Results doc: <c>docs/plans/2026-08-15-target-scale-load-test-results.md</c>.
+/// Design memo: <c>docs/plans/2026-08-15-target-scale-load-test-design.md</c>.
+/// </para>
+/// </summary>
+public class TargetScaleHarnessSmokeTests
+{
+    /// <summary>
+    /// Runs the harness at ~1/1000th of target scale for a few seconds and asserts the
+    /// pipeline is intact end to end: tag updates reach live stream subscribers, the
+    /// central health aggregator tracks every site, debug snapshots answer, the
+    /// store-and-forward buffer drains to empty, and a stalled subscriber does not cost
+    /// the healthy ones any events.
+    /// </summary>
+    /// <returns>A task representing the test run.</returns>
+    [Trait("Category", "Performance")]
+    [Fact]
+    public async Task Harness_AtSmokeScale_ProducesCoherentMeasurements()
+    {
+        var config = new HarnessConfig
+        {
+            Sites = 2,
+            InstancesPerSite = 10,
+            TagsPerInstance = 5,
+            TagUpdatePeriod = TimeSpan.FromSeconds(1),
+            SettleDuration = TimeSpan.FromSeconds(5),
+            SustainDuration = TimeSpan.FromSeconds(15),
+            SampleInterval = TimeSpan.FromSeconds(2),
+            // Shortened from the production 30 s only because the smoke window is 20 s.
+            HealthReportInterval = TimeSpan.FromSeconds(2),
+            DebugProbeInterval = TimeSpan.FromSeconds(2),
+            SubscribeSettleDuration = TimeSpan.FromSeconds(5),
+            StreamProbesPerSite = 3,
+            StoreAndForwardDrainMessages = 200,
+            SlowSubscriberEvents = 2_000,
+            ResultsPath = Path.Combine(Path.GetTempPath(), $"loadharness-smoke-{Guid.NewGuid():N}.json"),
+        };
+
+        using var cancellation = new CancellationTokenSource(TimeSpan.FromMinutes(10));
+        var result = await HarnessRun.ExecuteAsync(config, _ => { }, cancellation.Token);
+
+        // Tag updates flowed all the way through DCL -> InstanceActor -> site stream ->
+        // StreamRelayActor -> bounded channel -> subscriber.
+        Assert.True(result.TagUpdateLatency.Count > 0,
+            "No tag update latency samples — the DCL -> stream -> subscriber path did not carry traffic.");
+        Assert.True(result.StreamProbeReceived > 0, "Live stream subscribers received nothing.");
+        Assert.Equal(0, result.DriverSkippedNoCallback);
+
+        // Observability held up.
+        Assert.Equal(config.Sites, result.SitesTrackedByAggregator);
+        Assert.True(result.DebugSnapshotsCompleted > 0, "No debug snapshot completed.");
+        Assert.Equal(0, result.DebugSnapshotTimeouts);
+
+        // Store-and-forward drained completely (register row 50, first half).
+        Assert.NotNull(result.StoreAndForwardDrain);
+        Assert.Equal(0, result.StoreAndForwardDrain!.ResidualDepth);
+        Assert.True(result.StoreAndForwardDrain.DrainPerSecond > 0);
+
+        // A stalled subscriber costs the healthy ones nothing (register row 50, second
+        // half). This is the design's isolation claim, asserted rather than assumed.
+        Assert.NotNull(result.SlowSubscriber);
+        Assert.Equal(1.0, result.SlowSubscriber!.HealthyMinDeliveryRatio, precision: 2);
+        Assert.True(result.SlowSubscriber.SlowDeliveryRatio < 1.0,
+            "The deliberately stalled subscriber kept up, so the probe proved nothing.");
+    }
+}
@@ -31,6 +31,9 @@
    <ProjectReference Include="../../src/ZB.MOM.WW.ScadaBridge.SiteRuntime/ZB.MOM.WW.ScadaBridge.SiteRuntime.csproj" />
    <!-- Two-node failover rig (TwoNodeClusterFixture) — brings Host + Akka transitively. -->
    <ProjectReference Include="../../tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/ZB.MOM.WW.ScadaBridge.IntegrationTests.csproj" />
+    <!-- Target-scale load harness (register #25). Referenced so TargetScaleHarnessSmokeTests
+         can run it at CI scale; the full-scale protocol run is the standalone executable. -->
+    <ProjectReference Include="../../tests/ZB.MOM.WW.ScadaBridge.LoadHarness/ZB.MOM.WW.ScadaBridge.LoadHarness.csproj" />
  </ItemGroup>

 </Project>