add handler stack

Author: hannahkm

ddtrace/ext/tags.go

@@ -87,9 +87,12 @@ const (
 	// ErrorType specifies the error type.
 	ErrorType = "error.type"
 
-	// ErrorStack specifies the stack dump.
+	// ErrorStack specifies the stack dump when the error is thrown.
 	ErrorStack = "error.stack"
 
+	// ErrorHandlingStack specifies the stack dump when the error is captured.
+	ErrorHandlingStack = "error.handling.stack"
+
 	// ErrorDetails holds details about an error which implements a formatter.
 	ErrorDetails = "error.details"
 

ddtrace/tracer/span.go

@@ -441,11 +441,15 @@ func (s *Span) setTagError(value interface{}, cfg errorConfig) {
 			s.setMeta(ext.ErrorDetails, fmt.Sprintf("%+v", v))
 			if !cfg.noDebugStack {
 				s.setMeta(ext.ErrorStack, err.Format())
+				s.setMeta(ext.ErrorHandlingStack, takeStacktrace(cfg.stackFrames, cfg.stackSkip))
 			}
 			return
 		}
 		if !cfg.noDebugStack {
-			s.setMeta(ext.ErrorStack, takeStacktrace(cfg.stackFrames, cfg.stackSkip))
+			telemetry.Count(telemetry.NamespaceTracers, "errorstack.source", []string{"source:takeStacktrace"}).Submit(1)
+			stack := takeStacktrace(cfg.stackFrames, cfg.stackSkip)
+			s.setMeta(ext.ErrorStack, stack)
+			s.setMeta(ext.ErrorHandlingStack, stack)
 		}
 	case nil:
 		// no error
@@ -463,7 +467,6 @@ const defaultStackLength = 32
 // takeStacktrace takes a stack trace of maximum n entries, skipping the first skip entries.
 // If n is 0, up to 20 entries are retrieved.
 func takeStacktrace(n, skip uint) string {
-	telemetry.Count(telemetry.NamespaceTracers, "errorstack.source", []string{"source:takeStacktrace"}).Submit(1)
 	now := time.Now()
 	defer func() {
 		dur := float64(time.Since(now))

ddtrace/tracer/span_test.go

@@ -797,6 +797,10 @@ func TestErrorStack(t *testing.T) {
 		assert.NotEqual("", stack)
 		assert.Contains(stack, "tracer.TestErrorStack")
 		assert.Contains(stack, "tracer.createErrorTrace")
+
+		handlingStack := span.meta[ext.ErrorHandlingStack]
+		assert.NotEqual("", handlingStack)
+		assert.NotEqual(stack, handlingStack)
 		span.Finish()
 	})
 
@@ -817,6 +821,10 @@ func TestErrorStack(t *testing.T) {
 		assert.NotEqual("", stack)
 		assert.Contains(stack, "tracer.TestErrorStack")
 		assert.NotContains(stack, "tracer.createTestError") // this checks our old behavior
+
+		handlingStack := span.meta[ext.ErrorHandlingStack]
+		assert.NotEqual("", handlingStack)
+		assert.Equal(stack, handlingStack)
 		span.Finish()
 	})
 }
@@ -978,7 +986,6 @@ func TestSpanErrorStackMetrics(t *testing.T) {
 		}
 
 		assert.Equal(0.0, telemetryClient.Count(telemetry.NamespaceTracers, "errorstack.source", []string{"source:takeStacktrace"}).Get())
-		assert.Equal(0.0, telemetryClient.Distribution(telemetry.NamespaceTracers, "errorstack.duration", []string{"source:takeStacktrace"}).Get())
 
 		assert.Equal(5.0, telemetryClient.Count(telemetry.NamespaceTracers, "errorstack.source", []string{"source:TracerError"}).Get())
 		if !windows {