feat: upgrade Sentry SDK to 6.1.0-alpha.1 and add trace-connected metrics

Upgrades Sentry .NET SDK from 6.0.0 to 6.1.0-alpha.1 to test the new
experimental trace-connected metrics API from PR getsentry/sentry-dotnet#4834.

Changes:
- Upgrade Sentry SDK to 6.1.0-alpha.1
- Add SentryClientMetrics decorator that emits metrics to Sentry
- Enable experimental metrics in all apps (Server, Console, Android)
- Use SentryClientMetrics in DI registrations

The new metrics API provides:
- AddCounter: for counting events (files, uploads, errors)
- RecordDistribution: for value distributions (uploaded bytes)
- RecordGauge: for point-in-time values (jobs in flight)

Metrics are automatically correlated with the active trace/span.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: bruno-garcia

src/Directory.Packages.props

@@ -1,7 +1,7 @@
 <Project>
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
-    <SentryVersion>6.0.0</SentryVersion>
+    <SentryVersion>6.1.0-alpha.1</SentryVersion>
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Include="Sentry" Version="$(SentryVersion)" />

src/SymbolCollector.Android.Library/Host.cs

@@ -40,6 +40,7 @@ public static IHost Init(Context context, string dsn, string? sentryTrace = null
         {
             o.CaptureFailedRequests = true;
             o.EnableLogs = true;
+            o.Experimental.EnableMetrics = true;
 
             o.SetBeforeSend(@event =>
             {

src/SymbolCollector.Console/Program.cs

@@ -13,7 +13,7 @@ namespace SymbolCollector.Console;
 
 internal class Program
 {
-    private static readonly ClientMetrics Metrics = new ClientMetrics();
+    private static readonly SentryClientMetrics Metrics = new SentryClientMetrics();
 
     static async Task<int> Main(
         string? upload = null,
@@ -221,6 +221,7 @@ private static void Bootstrap(Args args)
             o.IsGlobalModeEnabled = true;
             o.CaptureFailedRequests = true;
             o.EnableLogs = true;
+            o.Experimental.EnableMetrics = true;
 
 #if DEBUG
             o.Environment = "development";

src/SymbolCollector.Core/SentryClientMetrics.cs

@@ -0,0 +1,148 @@
+namespace SymbolCollector.Core;
+
+/// <summary>
+/// A decorator for <see cref="ClientMetrics"/> that also emits metrics to Sentry's trace-connected metrics API.
+/// </summary>
+/// <remarks>
+/// This integrates with Sentry SDK 6.1.0's new experimental trace-connected metrics feature.
+/// Metrics are attached to the current trace/span for correlation in Sentry's UI.
+/// Access via <c>SentrySdk.Experimental.Metrics</c> after enabling with <c>options.Experimental.EnableMetrics = true</c>.
+/// </remarks>
+public class SentryClientMetrics : ClientMetrics
+{
+    /// <summary>
+    /// Records a file processed event, incrementing both local and Sentry counters.
+    /// </summary>
+    public new void FileProcessed()
+    {
+        base.FileProcessed();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.files_processed", 1);
+    }
+
+    /// <summary>
+    /// Records a Mach-O file discovery.
+    /// </summary>
+    public new void MachOFileFound()
+    {
+        base.MachOFileFound();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.debug_images_found", 1,
+            [new KeyValuePair<string, object>("format", "macho")]);
+    }
+
+    /// <summary>
+    /// Records an ELF file discovery.
+    /// </summary>
+    public new void ElfFileFound()
+    {
+        base.ElfFileFound();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.debug_images_found", 1,
+            [new KeyValuePair<string, object>("format", "elf")]);
+    }
+
+    /// <summary>
+    /// Records a Fat Mach-O file discovery.
+    /// </summary>
+    public new void FatMachOFileFound()
+    {
+        base.FatMachOFileFound();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.debug_images_found", 1,
+            [new KeyValuePair<string, object>("format", "fat_macho")]);
+    }
+
+    /// <summary>
+    /// Records a failed upload.
+    /// </summary>
+    public new void FailedToUpload()
+    {
+        base.FailedToUpload();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.uploads", 1,
+            [new KeyValuePair<string, object>("status", "failed")]);
+    }
+
+    /// <summary>
+    /// Records a parse failure.
+    /// </summary>
+    public new void FailedToParse()
+    {
+        base.FailedToParse();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.parse_failures", 1);
+    }
+
+    /// <summary>
+    /// Records a successful upload.
+    /// </summary>
+    public new void SuccessfulUpload()
+    {
+        base.SuccessfulUpload();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.uploads", 1,
+            [new KeyValuePair<string, object>("status", "success")]);
+    }
+
+    /// <summary>
+    /// Records when a file already existed on the server.
+    /// </summary>
+    public new void AlreadyExisted()
+    {
+        base.AlreadyExisted();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.uploads", 1,
+            [new KeyValuePair<string, object>("status", "already_exists")]);
+    }
+
+    /// <summary>
+    /// Removes jobs from the in-flight count.
+    /// </summary>
+    public new void JobsInFlightRemove(int tasksCount)
+    {
+        base.JobsInFlightRemove(tasksCount);
+        SentrySdk.Experimental.Metrics.RecordGauge("symbol_collector.jobs_in_flight", JobsInFlightCount);
+    }
+
+    /// <summary>
+    /// Adds jobs to the in-flight count.
+    /// </summary>
+    public new void JobsInFlightAdd(int tasksCount)
+    {
+        base.JobsInFlightAdd(tasksCount);
+        SentrySdk.Experimental.Metrics.RecordGauge("symbol_collector.jobs_in_flight", JobsInFlightCount);
+    }
+
+    /// <summary>
+    /// Records bytes uploaded, emitting as a distribution for percentile analysis.
+    /// </summary>
+    public new void UploadedBytesAdd(long bytes)
+    {
+        base.UploadedBytesAdd(bytes);
+        // Use distribution for uploaded bytes to capture percentiles and histograms
+        SentrySdk.Experimental.Metrics.RecordDistribution("symbol_collector.uploaded_bytes", bytes, "byte");
+    }
+
+    /// <summary>
+    /// Records an unauthorized access error.
+    /// </summary>
+    public new void FileOrDirectoryUnauthorizedAccess()
+    {
+        base.FileOrDirectoryUnauthorizedAccess();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.access_errors", 1,
+            [new KeyValuePair<string, object>("type", "unauthorized")]);
+    }
+
+    /// <summary>
+    /// Records a directory not found error.
+    /// </summary>
+    public new void DirectoryDoesNotExist()
+    {
+        base.DirectoryDoesNotExist();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.access_errors", 1,
+            [new KeyValuePair<string, object>("type", "directory_not_found")]);
+    }
+
+    /// <summary>
+    /// Records a file not found error.
+    /// </summary>
+    public new void FileDoesNotExist()
+    {
+        base.FileDoesNotExist();
+        SentrySdk.Experimental.Metrics.AddCounter("symbol_collector.access_errors", 1,
+            [new KeyValuePair<string, object>("type", "file_not_found")]);
+    }
+}

src/SymbolCollector.Server/Program.cs

@@ -75,6 +75,7 @@ private static IHostBuilder CreateHostBuilder(string[] args) =>
                     o.MinimumBreadcrumbLevel = LogLevel.Debug;
                     o.CaptureFailedRequests = true;
                     o.EnableLogs = true;
+                    o.Experimental.EnableMetrics = true;
 
                     // https://github.com/getsentry/symbol-collector/issues/205
                     // o.CaptureBlockingCalls = true;

src/SymbolCollector.Server/Startup.cs

@@ -24,7 +24,8 @@ public void ConfigureServices(IServiceCollection services)
 
         services.AddSingleton<ObjectFileParser>();
         services.AddSingleton<FatBinaryReader>();
-        services.AddSingleton<ClientMetrics>();
+        services.AddSingleton<SentryClientMetrics>();
+        services.AddSingleton<ClientMetrics>(sp => sp.GetRequiredService<SentryClientMetrics>());
         services.AddSingleton<IBatchFinalizer, SymsorterBatchFinalizer>();
         services.AddSingleton<ISymbolGcsWriter, SymbolGcsWriter>();
         services.AddSingleton<IStorageClientFactory, StorageClientFactory>();