feat: Tracing without performance

src/Sentry.AspNet/HttpContextExtensions.cs

@@ -1,4 +1,3 @@
-using System.Security.Policy;
 using Sentry.Extensibility;
 
 namespace Sentry.AspNet;
@@ -91,12 +90,6 @@ public static ITransaction StartSentryTransaction(this HttpContext httpContext)
         const string transactionOperation = "http.server";
 
         var transactionContext = SentrySdk.ContinueTrace(traceHeader, baggageHeader, transactionName, transactionOperation);
-        if (transactionContext is null)
-        {
-            throw new NullReferenceException("Failed to create a transaction context. " + "Tracing was " +
-                        "most likely disabled. Make sure set a `TraceSampler` and to set the `TracesSampleRate` > 0.");
-        }
-
         transactionContext.NameSource = TransactionNameSource.Url;
 
         var customSamplingContext = new Dictionary<string, object?>(3, StringComparer.Ordinal)

src/Sentry.AspNetCore/SentryMiddleware.cs

@@ -18,9 +18,9 @@ namespace Sentry.AspNetCore;
 /// </summary>
 internal class SentryMiddleware : IMiddleware
 {
-    internal const string TraceHeaderItemKey = "sentry-trace-header";
-    internal const string BaggageHeaderItemKey = "sentry-baggage-header";
-    internal const string TransactionContextItemKey = "sentry-transaction-context";
+    internal static readonly object TraceHeaderItemKey = new();
+    internal static readonly object BaggageHeaderItemKey = new();
+    internal static readonly object TransactionContextItemKey = new();
 
     private readonly Func<IHub> _getHub;
     private readonly SentryAspNetCoreOptions _options;
@@ -99,7 +99,7 @@ public async Task InvokeAsync(HttpContext context, RequestDelegate next)
             var baggageHeader = context.TryGetBaggageHeader(_options);
             var transactionContext = hub.ContinueTrace(traceHeader, baggageHeader);
 
-            // Adding the headers and thw TransactionContext to the context to be picked up by the Sentry tracing middleware
+            // Adding the headers and the TransactionContext to the context to be picked up by the Sentry tracing middleware
             context.Items.Add(TraceHeaderItemKey, traceHeader);
             context.Items.Add(BaggageHeaderItemKey, baggageHeader);
             context.Items.Add(TransactionContextItemKey, transactionContext);

src/Sentry.AspNetCore/SentryTracingMiddleware.cs

@@ -40,7 +40,7 @@ public SentryTracingMiddleware(
             context.Items.TryGetValue(SentryMiddleware.TransactionContextItemKey, out var transactionContextObject);
             if (transactionContextObject is not TransactionContext transactionContext)
             {
-                throw new KeyNotFoundException($"Failed to retrieve the '{SentryMiddleware.TransactionContextItemKey}' from the HttpContext items.");
+                throw new KeyNotFoundException($"Failed to retrieve the '{nameof(SentryMiddleware.TransactionContextItemKey)}' from the HttpContext items.");
             }
 
             // It's important to try and set the transaction name to some value here so that it's available for use
@@ -76,8 +76,7 @@ public SentryTracingMiddleware(
                 dynamicSamplingContext = DynamicSamplingContext.Empty;
             }
 
-            var hub = _getHub();
-            var transaction = hub.StartTransaction(transactionContext, customSamplingContext, dynamicSamplingContext);
+            var transaction = _getHub().StartTransaction(transactionContext, customSamplingContext, dynamicSamplingContext);
 
             _options.LogInfo(
                 "Started transaction with span ID '{0}' and trace ID '{1}'.",

src/Sentry/DynamicSamplingContext.cs

@@ -146,7 +146,19 @@ public static DynamicSamplingContext CreateFromTransaction(TransactionTracer tra
     }
 
     public static DynamicSamplingContext CreateFromPropagationContext(SentryPropagationContext propagationContext, SentryOptions options)
-        => new(propagationContext.TraceId, options.ParsedDsn.PublicKey, propagationContext.IsSampled);
+    {
+        var publicKey = options.ParsedDsn.PublicKey;
+        var traceId = propagationContext.TraceId;
+        var release = options.SettingLocator.GetRelease();
+        var environment = options.SettingLocator.GetEnvironment();
+
+        return new DynamicSamplingContext(
+            traceId,
+            publicKey,
+            null,
+            release: release,
+            environment:environment);
+    }
 }
 
 internal static class DynamicSamplingContextExtensions
@@ -156,4 +168,7 @@ internal static class DynamicSamplingContextExtensions
 
     public static DynamicSamplingContext CreateDynamicSamplingContext(this TransactionTracer transaction, SentryOptions options)
         => DynamicSamplingContext.CreateFromTransaction(transaction, options);
+
+    public static DynamicSamplingContext CreateDynamicSamplingContext(this SentryPropagationContext propagationContext, SentryOptions options)
+        => DynamicSamplingContext.CreateFromPropagationContext(propagationContext, options);
 }

src/Sentry/Extensibility/DisabledHub.cs

@@ -87,11 +87,15 @@ public void BindException(Exception exception, ISpan span)
     /// <summary>
     /// Returns null.
     /// </summary>
-    public TransactionContext? ContinueTrace(
+    public TransactionContext ContinueTrace(
         SentryTraceHeader? traceHeader,
         BaggageHeader? baggageHeader,
         string? name = null,
-        string? operation = null) => null;
+        string? operation = null)
+    {
+        // Transactions from DisabledHub are always sampled out
+        return new TransactionContext(string.Empty, string.Empty, false);
+    }
 
     /// <summary>
     /// No-Op.

src/Sentry/Extensibility/HubAdapter.cs

@@ -103,17 +103,9 @@ public void BindException(Exception exception, ISpan span) =>
     /// Forwards the call to <see cref="SentrySdk"/>.
     /// </summary>
     [DebuggerStepThrough]
-    [Obsolete("This method will be removed in a future major version. Use the `GetTraceParent` instead.")]
     public SentryTraceHeader? GetTraceHeader()
         => SentrySdk.GetTraceHeader();
 
-    /// <summary>
-    /// Forwards the call to <see cref="SentrySdk"/>.
-    /// </summary>
-    [DebuggerStepThrough]
-    public SentryTraceHeader? GetTraceParent()
-        => SentrySdk.GetTraceParent();
-
     /// <summary>
     /// Forwards the call to <see cref="SentrySdk"/>.
     /// </summary>
@@ -125,7 +117,7 @@ public void BindException(Exception exception, ISpan span) =>
     /// Forwards the call to <see cref="SentrySdk"/>.
     /// </summary>
     [DebuggerStepThrough]
-    public TransactionContext? ContinueTrace(
+    public TransactionContext ContinueTrace(
         SentryTraceHeader? traceHeader,
         BaggageHeader? baggageHeader,
         string? name = null,

src/Sentry/IHub.cs

@@ -40,17 +40,12 @@ ITransaction StartTransaction(
     ISpan? GetSpan();
 
     /// <summary>
-    /// Gets the Sentry trace header for the last active span.
+    /// Gets the Sentry trace header that allows tracing across services
     /// </summary>
     SentryTraceHeader? GetTraceHeader();
 
     /// <summary>
-    /// Gets the Sentry trace header of the parent that allows tracing across services
-    /// </summary>
-    SentryTraceHeader? GetTraceParent();
-
-    /// <summary>
-    /// Gets the Sentry "baggage" header that allows tracing across services
+    /// Gets the Sentry baggage header that allows tracing across services
     /// </summary>
     BaggageHeader? GetBaggage();
 
@@ -60,7 +55,7 @@ ITransaction StartTransaction(
     /// <remarks>
     /// If no "sentry-trace" header is provided a random trace ID and span ID is created.
     /// </remarks>
-    TransactionContext? ContinueTrace(
+    TransactionContext ContinueTrace(
         SentryTraceHeader? traceHeader,
         BaggageHeader? baggageHeader,
         string? name = null,

src/Sentry/Internal/Hub.cs

@@ -195,34 +195,32 @@ public void BindException(Exception exception, ISpan span)
 
     public ISpan? GetSpan() => ScopeManager.GetCurrent().Key.Span;
 
-    [Obsolete("Use GetTraceParent instead")]
-    public SentryTraceHeader? GetTraceHeader() => GetTraceParent();
-
-    public SentryTraceHeader GetTraceParent()
+    public SentryTraceHeader GetTraceHeader()
     {
-        if (_options.IsTracingEnabled && GetSpan()?.GetTraceHeader() is { } traceHeader)
+        if (GetSpan()?.GetTraceHeader() is { } traceHeader)
         {
             return traceHeader;
         }
 
-        // Fallback: Either tracing was disabled or there was no span on the current scope.
+        // With either tracing disabled or no active span on the current scope we fall back to the propagation context
         var propagationContext = ScopeManager.GetCurrent().Key.PropagationContext;
-        // With performance disabled, we must not append a sampling decision.
+        // In either case, we must not append a sampling decision.
         return new SentryTraceHeader(propagationContext.TraceId, propagationContext.SpanId, null);
     }
 
-    public BaggageHeader? GetBaggage()
+    public BaggageHeader GetBaggage()
     {
-        if (_options.IsTracingEnabled && GetSpan() is TransactionTracer {DynamicSamplingContext: {IsEmpty: false} dsc} )
+        if (GetSpan() is TransactionTracer { DynamicSamplingContext: { IsEmpty: false } dsc } )
         {
             return dsc.ToBaggageHeader();
         }
 
         var propagationContext = ScopeManager.GetCurrent().Key.PropagationContext;
-        return propagationContext.DynamicSamplingContext?.ToBaggageHeader();
+        propagationContext.DynamicSamplingContext ??= propagationContext.CreateDynamicSamplingContext(_options);
+        return propagationContext.DynamicSamplingContext.ToBaggageHeader();
     }
 
-    public TransactionContext? ContinueTrace(
+    public TransactionContext ContinueTrace(
         SentryTraceHeader? traceHeader,
         BaggageHeader? baggageHeader,
         string? name = null,
@@ -231,15 +229,12 @@ public SentryTraceHeader GetTraceParent()
         var propagationContext = SentryPropagationContext.CreateFromHeaders(_options.DiagnosticLogger, traceHeader, baggageHeader);
         ConfigureScope(scope => scope.PropagationContext = propagationContext);
 
-        if (_options.IsTracingEnabled)
-        {
-            return new TransactionContext(
-                name ?? string.Empty,
-                operation ?? string.Empty,
-                new SentryTraceHeader(propagationContext.TraceId, propagationContext.SpanId, propagationContext.IsSampled));
-        }
-
-        return null;
+        // If we have to create a new SentryTraceHeader we don't make a sampling decision
+        traceHeader ??= new SentryTraceHeader(propagationContext.TraceId, propagationContext.SpanId, null);
+        return new TransactionContext(
+            name ?? string.Empty,
+            operation ?? string.Empty,
+            traceHeader);
     }
 
     public void StartSession()
@@ -401,7 +396,7 @@ SentryId IHubEx.CaptureEventInternal(SentryEvent evt, Hint? hint, Scope? scope)
             else
             {
                 var propagationContext = actualScope.PropagationContext;
-                propagationContext.DynamicSamplingContext ??= DynamicSamplingContext.CreateFromPropagationContext(propagationContext, _options);
+                propagationContext.DynamicSamplingContext ??= propagationContext.CreateDynamicSamplingContext(_options);
 
                 evt.Contexts.Trace.TraceId = propagationContext.TraceId;
                 evt.Contexts.Trace.SpanId = propagationContext.SpanId;

src/Sentry/SentryHttpMessageHandler.cs

@@ -148,7 +148,7 @@ private void HandleResponse(HttpResponseMessage response, ISpan? span, string me
     private void AddSentryTraceHeader(HttpRequestMessage request)
     {
         // Set trace header if it hasn't already been set
-        if (!request.Headers.Contains(SentryTraceHeader.HttpHeaderName) && _hub.GetTraceParent() is { } traceHeader)
+        if (!request.Headers.Contains(SentryTraceHeader.HttpHeaderName) && _hub.GetTraceHeader() is { } traceHeader)
         {
             request.Headers.Add(SentryTraceHeader.HttpHeaderName, traceHeader.ToString());
         }

src/Sentry/SentryOptions.cs

@@ -317,7 +317,7 @@ public string? Dsn {
         }
     }
 
-    private Dsn? _parsedDsn;
+    internal Dsn? _parsedDsn;
     internal Dsn ParsedDsn => _parsedDsn ??= Sentry.Dsn.Parse(Dsn!);
 
     private readonly Lazy<string> _sentryBaseUrl;

src/Sentry/SentryPropagationContext.cs

@@ -7,20 +7,33 @@ internal class SentryPropagationContext
     public SentryId TraceId { get; }
     public SpanId SpanId { get; }
     public SpanId? ParentSpanId { get; }
-    public bool? IsSampled { get; }
-    public DynamicSamplingContext? DynamicSamplingContext { get; set; }
 
-    private SentryPropagationContext(
+    private DynamicSamplingContext? _dynamicSamplingContext;
+    public DynamicSamplingContext? DynamicSamplingContext
+    {
+        get => _dynamicSamplingContext;
+        set
+        {
+            if (_dynamicSamplingContext is null)
+            {
+                _dynamicSamplingContext = value;
+            }
+            else
+            {
+                throw new Exception("should not do that.");
+            }
+        }
+    }
+
+    internal SentryPropagationContext(
         SentryId traceId,
         SpanId parentSpanId,
-        bool? isSampled,
-        DynamicSamplingContext? dynamicSamplingContext)
+        DynamicSamplingContext? dynamicSamplingContext = null)
     {
         TraceId = traceId;
         SpanId = SpanId.Create();
         ParentSpanId = parentSpanId;
         DynamicSamplingContext = dynamicSamplingContext;
-        IsSampled = isSampled;
     }
 
     public SentryPropagationContext()
@@ -31,28 +44,15 @@ public SentryPropagationContext()
 
     public static SentryPropagationContext CreateFromHeaders(IDiagnosticLogger? logger, SentryTraceHeader? traceHeader, BaggageHeader? baggageHeader)
     {
+        logger?.LogDebug("Creating a propagation context from headers.");
+
         if (traceHeader == null)
         {
+            logger?.LogInfo("Sentry trace header is null. Creating new Sentry Propagation Context.");
             return new SentryPropagationContext();
         }
 
-        try
-        {
-            DynamicSamplingContext? dynamicSamplingContext = null;
-            if (baggageHeader is not null)
-            {
-                dynamicSamplingContext = baggageHeader.CreateDynamicSamplingContext();
-            }
-
-            dynamicSamplingContext?.Items.TryGetValue("sampled", out var isSampled);
-            return new SentryPropagationContext(traceHeader.TraceId, traceHeader.SpanId, traceHeader.IsSampled, dynamicSamplingContext);
-        }
-        catch (Exception e)
-        {
-            logger?.LogError(
-                "Failed to create the 'SentryPropagationContext' from provided headers: '{0}', '{1}'. " +
-                        "\nFalling back to new PropagationContext.", e, traceHeader, baggageHeader);
-            return new SentryPropagationContext();
-        }
+        var dynamicSamplingContext = baggageHeader?.CreateDynamicSamplingContext();
+        return new SentryPropagationContext(traceHeader.TraceId, traceHeader.SpanId, dynamicSamplingContext);
     }
 }

src/Sentry/SentrySdk.cs

@@ -611,20 +611,12 @@ public static void BindException(Exception exception, ISpan span)
         => CurrentHub.GetSpan();
 
     /// <summary>
-    /// Gets the Sentry trace header.
+    /// Gets the Sentry trace header of the parent that allows tracing across services
     /// </summary>
     [DebuggerStepThrough]
-    [Obsolete("This method will be removed in a future major version. Use the `GetTraceParent` instead.")]
     public static SentryTraceHeader? GetTraceHeader()
         => CurrentHub.GetTraceHeader();
 
-    /// <summary>
-    /// Gets the Sentry trace header of the parent that allows tracing across services
-    /// </summary>
-    [DebuggerStepThrough]
-    public static SentryTraceHeader? GetTraceParent()
-        => CurrentHub.GetTraceParent();
-
     /// <summary>
     /// Gets the Sentry "baggage" header that allows tracing across services
     /// </summary>
@@ -639,7 +631,7 @@ public static void BindException(Exception exception, ISpan span)
     /// If no "sentry-trace" header is provided a random trace ID and span ID is created.
     /// </remarks>
     [DebuggerStepThrough]
-    public static TransactionContext? ContinueTrace(
+    public static TransactionContext ContinueTrace(
         SentryTraceHeader? traceHeader,
         BaggageHeader? baggageHeader,
         string? name = null,