Fix Linux comparison fixture cleanup and record CI revision

Author: KSemenenko

benchmarks/KeyLoad.Comparisons/ReportWriter.cs

@@ -32,7 +32,7 @@ public static string Markdown(ComparisonReport report)
         text.AppendLine($"Run: {report.RunId}. Seed: {report.Options.Seed}. Corpus SHA256: `{report.DatasetSha256}`.");
         text.AppendLine($"\n{report.Options.Documents} documents, {report.Options.PayloadBytes} UTF-8 bytes/document, {report.Options.Dimensions} float32 dimensions, top-{report.Options.TopK}, {report.Options.Operations} attempts/case, concurrency {report.Options.Concurrency}, {report.Options.Warmup} warmup requests, {report.Options.Repetitions} repetitions.");
         text.AppendLine($"\nHost: {report.HostOs}; {report.Architecture}; {report.LogicalProcessors} logical processors; {report.Runtime}. Load: {report.LoadModel}. Storage: {report.Storage}. Source revision: {report.SourceRevision ?? "unrecorded"}.");
-        text.AppendLine("\nExploratory development run. Engine topology, resource allocation, authorization, transports and write guarantees differ. These rows show observed speed, not an equal-durability or production winner. Docker VM overhead applies to external engines; KeyLoad voters run as host processes. Same-host voters do not represent independent failure domains. No primary performance target has been qualified.\n");
+        text.AppendLine("\nExploratory development run. Engine topology, resource allocation, authorization, transports and write guarantees differ. These rows show observed speed, not an equal-durability or production winner. External engines run in containers; Docker Desktop adds VM overhead where used. KeyLoad voters run as host processes. Same-host voters do not represent independent failure domains. No primary performance target has been qualified.\n");
         text.AppendLine("| Engine | Version | Topology | Write acknowledgement | Read / transport / policy | Image |\n|---|---|---|---|---|---|");
         foreach (var target in report.Targets)
             text.AppendLine($"| {target.Name} | {target.Version} | {target.Topology} | {target.WriteAcknowledgement} | {target.ReadContract}; {target.Transport}; {target.Authorization} | {target.Image ?? "source checkout"} |");

tests/KeyLoad.ComparisonTests/ComparisonTests.cs

@@ -1,4 +1,5 @@
 using System.Collections.Concurrent;
+using System.Diagnostics;
 using System.Text.Json;
 using Aspire.Hosting;
 using Aspire.Hosting.ApplicationModel;
@@ -34,7 +35,8 @@ public async Task AspireRunsIdenticalScenariosAgainstRealRf3AndExternalEngines()
             $"--Benchmarks:Output={output}", $"--Benchmarks:Documents={options.Documents}", $"--Benchmarks:Operations={options.Operations}", $"--Benchmarks:Warmup={options.Warmup}",
             $"--Benchmarks:Repetitions={options.Repetitions}", $"--Benchmarks:Concurrency={options.Concurrency}", $"--Benchmarks:Dimensions={options.Dimensions}",
             $"--Benchmarks:TopK={options.TopK}", $"--Benchmarks:PayloadBytes={options.PayloadBytes}", $"--Benchmarks:Seed={options.Seed}",
-            $"--Benchmarks:TimeoutSeconds={options.TimeoutSeconds}"], timeout.Token);
+            $"--Benchmarks:TimeoutSeconds={options.TimeoutSeconds}",
+            $"--Benchmarks:SourceRevision={Environment.GetEnvironmentVariable("GITHUB_SHA") ?? "unrecorded"}"], timeout.Token);
         builder.Services.AddLogging(logging =>
         {
             logging.ClearProviders(); logging.AddConsole(); logging.SetMinimumLevel(LogLevel.Warning);
@@ -105,8 +107,40 @@ await app.ResourceNotifications.WaitForResourceAsync("comparisons",
             await captureLifetime.CancelAsync(); await capture; await Task.WhenAll(logCaptures.Values);
             Directory.CreateDirectory(evidence);
             await File.WriteAllLinesAsync(Path.Combine(evidence, "runner.log"), lines, CancellationToken.None);
+            var redis = app.Services.GetRequiredService<DistributedApplicationModel>().Resources
+                .OfType<ContainerResource>().Single(resource => resource.Name == "benchmark-redis");
             await app.StopAsync(CancellationToken.None);
-            if (Directory.Exists(root)) Directory.Delete(root, true);
+            await DeleteDataAsync(root, redis);
         }
     }
+
+    private static async Task DeleteDataAsync(string root, ContainerResource redis)
+    {
+        if (!Directory.Exists(root)) return;
+        try { Directory.Delete(root, true); return; }
+        catch (UnauthorizedAccessException) when (OperatingSystem.IsLinux()) { }
+
+        // Native Linux bind mounts retain container UIDs. Use the already pinned image to remove
+        // only this test's external data after all resources have stopped; never prune Docker data.
+        var external = Path.Combine(root, "external");
+        if (!Directory.Exists(external) || !redis.TryGetContainerImageName(out var image))
+            throw new IOException("Cannot clean the comparison run's container-owned data.");
+        var start = new ProcessStartInfo("docker") { RedirectStandardError = true, RedirectStandardOutput = true };
+        foreach (var argument in new[]
+        {
+            "run", "--rm", "--pull", "never", "--network", "none", "--read-only", "--user", "0:0",
+            "--cap-drop", "ALL", "--cap-add", "DAC_OVERRIDE", "--entrypoint", "/bin/sh",
+            "--mount", $"type=bind,source={external},target=/data", image!, "-c", "rm -rf /data/*"
+        }) start.ArgumentList.Add(argument);
+        using var process = Process.Start(start) ?? throw new IOException("Cannot start comparison data cleanup.");
+        var error = process.StandardError.ReadToEndAsync();
+        var output = process.StandardOutput.ReadToEndAsync();
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(30));
+        try { await process.WaitForExitAsync(timeout.Token); }
+        catch (OperationCanceledException) { process.Kill(entireProcessTree: true); throw; }
+        await output;
+        if (process.ExitCode != 0) throw new IOException($"Comparison data cleanup failed: {await error}");
+        await error;
+        Directory.Delete(root, true);
+    }
 }