feat: add benchmark test project for Go vs .NET server comparison

Side-by-side performance benchmarks using NATS.Client.Core against both servers on ephemeral ports. Includes core pub/sub, request/reply latency, and JetStream throughput tests with comparison output and benchmarks_comparison.md results. Also fixes timestamp flakiness in StoreInterfaceTests by using explicit timestamps.
2026-03-13 01:23:31 -04:00
parent e9c86c51c3
commit 37575dc41c
28 changed files with 2264 additions and 12 deletions
--- a/tests/NATS.Server.Benchmark.Tests/CorePubSub/FanOutTests.cs
+++ b/tests/NATS.Server.Benchmark.Tests/CorePubSub/FanOutTests.cs
@@ -0,0 +1,99 @@
+using NATS.Client.Core;
+using NATS.Server.Benchmark.Tests.Harness;
+using NATS.Server.Benchmark.Tests.Infrastructure;
+using Xunit.Abstractions;
+
+namespace NATS.Server.Benchmark.Tests.CorePubSub;
+
+[Collection("Benchmark-Core")]
+public class FanOutTests(CoreServerPairFixture fixture, ITestOutputHelper output)
+{
+    [Fact]
+    [Trait("Category", "Benchmark")]
+    public async Task FanOut1To4_128B()
+    {
+        const int payloadSize = 128;
+        const int messageCount = 10_000;
+        const int subscriberCount = 4;
+
+        var dotnetResult = await RunFanOut("Fan-Out 1:4 (128B)", "DotNet", payloadSize, messageCount, subscriberCount, fixture.CreateDotNetClient);
+
+        if (fixture.GoAvailable)
+        {
+            var goResult = await RunFanOut("Fan-Out 1:4 (128B)", "Go", payloadSize, messageCount, subscriberCount, fixture.CreateGoClient);
+            BenchmarkResultWriter.WriteComparison(output, goResult, dotnetResult);
+        }
+        else
+        {
+            BenchmarkResultWriter.WriteSingle(output, dotnetResult);
+        }
+    }
+
+    private static async Task<BenchmarkResult> RunFanOut(string name, string serverType, int payloadSize, int messageCount, int subscriberCount, Func<NatsConnection> createClient)
+    {
+        var payload = new byte[payloadSize];
+        var subject = $"bench.fanout.{serverType.ToLowerInvariant()}.{Guid.NewGuid():N}";
+
+        await using var pubClient = createClient();
+        await pubClient.ConnectAsync();
+
+        var subClients = new NatsConnection[subscriberCount];
+        var subs = new INatsSub<byte[]>[subscriberCount];
+        var subTasks = new Task[subscriberCount];
+        var totalExpected = messageCount * subscriberCount;
+        var totalReceived = 0;
+        var tcs = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+
+        for (var i = 0; i < subscriberCount; i++)
+        {
+            subClients[i] = createClient();
+            await subClients[i].ConnectAsync();
+            subs[i] = await subClients[i].SubscribeCoreAsync<byte[]>(subject);
+        }
+
+        // Flush to ensure all subscriptions are propagated
+        foreach (var client in subClients)
+            await client.PingAsync();
+        await pubClient.PingAsync();
+
+        // Start reading after subscriptions are confirmed
+        for (var i = 0; i < subscriberCount; i++)
+        {
+            var sub = subs[i];
+            subTasks[i] = Task.Run(async () =>
+            {
+                await foreach (var _ in sub.Msgs.ReadAllAsync())
+                {
+                    if (Interlocked.Increment(ref totalReceived) >= totalExpected)
+                    {
+                        tcs.TrySetResult();
+                        return;
+                    }
+                }
+            });
+        }
+
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        for (var i = 0; i < messageCount; i++)
+            await pubClient.PublishAsync(subject, payload);
+        await pubClient.PingAsync();
+
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(60));
+        await tcs.Task.WaitAsync(cts.Token);
+        sw.Stop();
+
+        foreach (var sub in subs)
+            await sub.UnsubscribeAsync();
+        foreach (var client in subClients)
+            await client.DisposeAsync();
+
+        return new BenchmarkResult
+        {
+            Name = name,
+            ServerType = serverType,
+            TotalMessages = totalExpected,
+            TotalBytes = (long)totalExpected * payloadSize,
+            Duration = sw.Elapsed,
+        };
+    }
+}