fix(ddtrace/tracer): wire version on aggregation key when adding a span to client-side stats

darccio · darccio · commit 5655505e021b · 2026-05-06T18:12:45.000+02:00
diff --git a/ddtrace/tracer/stats.go b/ddtrace/tracer/stats.go
@@ -67,6 +67,7 @@ type concentrator struct {
 type tracerStatSpan struct {
 	statSpan *stats.StatSpan
 	origin   string
+	version  string // per-span version tag; "" means use global aggKey version
 }
 
 // newConcentrator creates a new concentrator using the given tracer
@@ -197,10 +198,10 @@ func (c *concentrator) newTracerStatSpan(s *Span, obfuscator *obfuscate.Obfuscat
 	if !ok {
 		return nil, false
 	}
-	origin := s.meta[keyOrigin]
 	return &tracerStatSpan{
 		statSpan: statSpan,
-		origin:   origin,
+		origin:   s.meta[keyOrigin],
+		version:  s.meta[ext.Version],
 	}, true
 }
 
@@ -212,7 +213,11 @@ func (c *concentrator) shouldObfuscate() bool {
 
 // add s into the concentrator's internal stats buckets.
 func (c *concentrator) add(s *tracerStatSpan) {
-	c.spanConcentrator.AddSpan(s.statSpan, c.aggregationKey, "", nil, s.origin)
+	aggKey := c.aggregationKey
+	if s.version != "" {
+		aggKey.Version = s.version
+	}
+	c.spanConcentrator.AddSpan(s.statSpan, aggKey, "", nil, s.origin)
 }
 
 // Stop stops the concentrator and blocks until the operation completes.
diff --git a/ddtrace/tracer/stats_test.go b/ddtrace/tracer/stats_test.go
@@ -315,6 +315,83 @@ func TestConcentratorDefaultEnv(t *testing.T) {
 	})
 }
 
+func TestPerSpanVersionInStats(t *testing.T) {
+	bucketSize := int64(500_000)
+	makeSpan := func(version string) *Span {
+		s := &Span{
+			name:     "http.request",
+			start:    time.Now().UnixNano() + 3*bucketSize,
+			duration: 1,
+			metrics:  map[string]float64{keyMeasured: 1},
+		}
+		if version != "" {
+			s.meta = map[string]string{ext.Version: version}
+		}
+		return s
+	}
+
+	t.Run("per-span version propagates to stats payload", func(t *testing.T) {
+		spanVersion := "synthtracer-20250501120000"
+		transport := newDummyTransport()
+		c := newConcentrator(newTestConfigWithTransport(t, transport), bucketSize, &statsd.NoOpClientDirect{})
+
+		s := makeSpan(spanVersion)
+		ss, ok := c.newTracerStatSpan(s, nil)
+		require.True(t, ok)
+		c.Start()
+		c.In <- ss
+		c.Stop()
+
+		got := transport.Stats()
+		require.Len(t, got, 1)
+		assert.Equal(t, spanVersion, got[0].Version,
+			"per-span version tag must be used when no global version is configured")
+	})
+
+	t.Run("falls back to global config version when span has no version tag", func(t *testing.T) {
+		transport := newDummyTransport()
+		cfg, err := newTestConfig(withNoopInfoHTTPClient(), func(c *config) {
+			c.ddTransport = transport
+			c.internalConfig.SetVersion("global-v1.2.3", internalconfig.OriginCode)
+		})
+		require.NoError(t, err)
+		c := newConcentrator(cfg, bucketSize, &statsd.NoOpClientDirect{})
+
+		s := makeSpan("")
+		ss, ok := c.newTracerStatSpan(s, nil)
+		require.True(t, ok)
+		c.Start()
+		c.In <- ss
+		c.Stop()
+
+		got := transport.Stats()
+		require.Len(t, got, 1)
+		assert.Equal(t, "global-v1.2.3", got[0].Version)
+	})
+
+	t.Run("two spans with different versions produce separate payloads", func(t *testing.T) {
+		transport := newDummyTransport()
+		c := newConcentrator(newTestConfigWithTransport(t, transport), bucketSize, &statsd.NoOpClientDirect{})
+
+		s1 := makeSpan("v-timestamp-1")
+		s2 := makeSpan("v-timestamp-2")
+		ss1, ok := c.newTracerStatSpan(s1, nil)
+		require.True(t, ok)
+		ss2, ok := c.newTracerStatSpan(s2, nil)
+		require.True(t, ok)
+		c.Start()
+		c.In <- ss1
+		c.In <- ss2
+		c.Stop()
+
+		got := transport.Stats()
+		require.Len(t, got, 2)
+		versions := map[string]struct{}{got[0].Version: {}, got[1].Version: {}}
+		assert.Contains(t, versions, "v-timestamp-1")
+		assert.Contains(t, versions, "v-timestamp-2")
+	})
+}
+
 func TestStatsIncludeHTTPMethodAndEndpoint(t *testing.T) {
 	uniqueMethod := "POST"
 	uniqueEndpoint := "/__unique_endpoint__"
