tracer: enable 128-bit TraceID generation by default (#2335)

Co-authored-by: Dario Castañé <dario.castane@datadoghq.com>

ddtrace/opentelemetry/tracer_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace"
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/internal"
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
 	"gopkg.in/DataDog/dd-trace-go.v1/internal/log"
@@ -79,10 +80,8 @@ func TestSpanWithoutNewRoot(t *testing.T) {
 
 	parent, ddCtx := tracer.StartSpanFromContext(context.Background(), "otel.child")
 	_, child := tr.Start(ddCtx, "otel.child")
-	var parentBytes oteltrace.TraceID
-	// TraceID is big-endian so the LOW order bits are at the END of parentBytes
-	uint64ToByte(parent.Context().TraceID(), parentBytes[8:])
-	assert.Equal(parentBytes, child.SpanContext().TraceID())
+	parentCtxW3C := parent.Context().(ddtrace.SpanContextW3C)
+	assert.Equal(parentCtxW3C.TraceID128Bytes(), [16]byte(child.SpanContext().TraceID()))
 }
 
 func TestTracerOptions(t *testing.T) {

ddtrace/tracer/context_test.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"encoding/binary"
 	"encoding/hex"
+	"os"
 	"testing"
 
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace"
@@ -115,6 +116,7 @@ func Test128(t *testing.T) {
 	_, _, _, stop := startTestTracer(t)
 	defer stop()
 
+	os.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
 	span, _ := StartSpanFromContext(context.Background(), "http.request")
 	assert.NotZero(t, span.Context().TraceID())
 	w3cCtx, ok := span.Context().(ddtrace.SpanContextW3C)
@@ -129,7 +131,7 @@ func Test128(t *testing.T) {
 	assert.Equal(t, span.Context().TraceID(), binary.BigEndian.Uint64(idBytes[8:]))
 
 	// Enable 128 bit trace ids
-	t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "true")
+	os.Unsetenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED")
 	span128, _ := StartSpanFromContext(context.Background(), "http.request")
 	assert.NotZero(t, span128.Context().TraceID())
 	w3cCtx, ok = span128.Context().(ddtrace.SpanContextW3C)

ddtrace/tracer/span_test.go

@@ -527,9 +527,9 @@ func TestSpanError(t *testing.T) {
 	span.SetTag(ext.Error, err)
 	assert.Equal(int32(0), span.Error)
 
-	// '+2' is `_dd.p.dm` + `_dd.base_service`
+	// '+3' is `_dd.p.dm` + `_dd.base_service`, `_dd.p.tid`
 	t.Logf("%q\n", span.Meta)
-	assert.Equal(nMeta+2, len(span.Meta))
+	assert.Equal(nMeta+3, len(span.Meta))
 	assert.Equal("", span.Meta[ext.ErrorMsg])
 	assert.Equal("", span.Meta[ext.ErrorType])
 	assert.Equal("", span.Meta[ext.ErrorStack])
@@ -761,7 +761,7 @@ func TestSpanLog(t *testing.T) {
 	t.Run("128-bit-generation-only", func(t *testing.T) {
 		// Generate 128 bit trace ids, but don't log them. So only the lower
 		// 64 bits should be logged in decimal form.
-		t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "true")
+		// DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED is true by default
 		// DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED is false by default
 		assert := assert.New(t)
 		tracer, _, _, stop := startTestTracer(t, WithService("tracer.test"), WithEnv("testenv"))
@@ -777,8 +777,8 @@ func TestSpanLog(t *testing.T) {
 	t.Run("128-bit-logging-only", func(t *testing.T) {
 		// Logging 128-bit trace ids is enabled, but it's not present in
 		// the span. So only the lower 64 bits should be logged in decimal form.
+		t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
 		t.Setenv("DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED", "true")
-		// DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED is false by default
 		assert := assert.New(t)
 		tracer, _, _, stop := startTestTracer(t, WithService("tracer.test"), WithEnv("testenv"))
 		defer stop()
@@ -811,6 +811,7 @@ func TestSpanLog(t *testing.T) {
 		// Logging 128-bit trace ids is enabled, and a 128-bit trace id, so
 		// a quoted 32 byte hex string should be printed for the dd.trace_id.
 		t.Setenv("DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED", "true")
+		t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
 		assert := assert.New(t)
 		tracer, _, _, stop := startTestTracer(t, WithService("tracer.test"), WithEnv("testenv"))
 		defer stop()
@@ -826,6 +827,7 @@ func TestSpanLog(t *testing.T) {
 		// Logging 128-bit trace ids is enabled, and but the upper 64 bits
 		// are empty, so the dd.trace_id should be printed as raw digits (not hex).
 		t.Setenv("DD_TRACE_128_BIT_TRACEID_LOGGING_ENABLED", "true")
+		t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
 		assert := assert.New(t)
 		tracer, _, _, stop := startTestTracer(t, WithService("tracer.test"), WithEnv("testenv"))
 		defer stop()

ddtrace/tracer/spancontext.go

@@ -122,7 +122,7 @@ func newSpanContext(span *span, parent *spanContext) *spanContext {
 			context.setBaggageItem(k, v)
 			return true
 		})
-	} else if sharedinternal.BoolEnv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", false) {
+	} else if sharedinternal.BoolEnv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", true) {
 		// add 128 bit trace id, if enabled, formatted as big-endian:
 		// <32-bit unix seconds> <32 bits of zero> <64 random bits>
 		id128 := time.Duration(span.Start) / time.Second

ddtrace/tracer/textmap_test.go

@@ -9,13 +9,15 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
 	"sync"
 	"testing"
 
+	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace"
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/ext"
 	"gopkg.in/DataDog/dd-trace-go.v1/ddtrace/internal"
 	"gopkg.in/DataDog/dd-trace-go.v1/internal/httpmem"
@@ -359,6 +361,9 @@ func TestTextMapPropagator(t *testing.T) {
 			assert.Equal(t, strconv.Itoa(int(childSpanID)), dst["x-datadog-parent-id"])
 			assert.Equal(t, strconv.Itoa(int(childSpanID)), dst["x-datadog-trace-id"])
 			assert.Equal(t, "1", dst["x-datadog-sampling-priority"])
+			if tc.xDatadogTagsHeader != "" {
+				tc.xDatadogTagsHeader += fmt.Sprintf(",_dd.p.tid=%s", child.Context().(ddtrace.SpanContextW3C).TraceID128()[:16])
+			}
 			assertTraceTags(t, tc.xDatadogTagsHeader, dst["x-datadog-tags"])
 			if strings.Contains(tc.injectStyle, "tracecontext") {
 				// other unit tests check the value of these W3C headers, so just make sure they're present
@@ -401,12 +406,15 @@ func TestTextMapPropagator(t *testing.T) {
 	})
 
 	t.Run("InjectExtract", func(t *testing.T) {
+		os.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "true")
+		defer os.Unsetenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED")
 		t.Setenv(headerPropagationStyleExtract, "datadog")
 		t.Setenv(headerPropagationStyleInject, "datadog")
 		propagator := NewPropagator(&PropagatorConfig{
-			BaggagePrefix: "bg-",
-			TraceHeader:   "tid",
-			ParentHeader:  "pid",
+			BaggagePrefix:    "bg-",
+			TraceHeader:      "tid",
+			ParentHeader:     "pid",
+			MaxTagsHeaderLen: defaultMaxTagsHeaderLen,
 		})
 		tracer := newTracer(WithPropagator(propagator))
 		defer tracer.Stop()
@@ -425,7 +433,7 @@ func TestTextMapPropagator(t *testing.T) {
 
 		xctx, ok := sctx.(*spanContext)
 		assert.True(ok)
-		assert.Equal(xctx.traceID, ctx.traceID)
+		assert.Equal(xctx.traceID.HexEncoded(), ctx.traceID.HexEncoded())
 		assert.Equal(xctx.spanID, ctx.spanID)
 		assert.Equal(xctx.baggage, ctx.baggage)
 		assert.Equal(xctx.trace.priority, ctx.trace.priority)

ddtrace/tracer/tracer_test.go

@@ -715,6 +715,8 @@ func TestTracerStartSpanOptions128(t *testing.T) {
 	defer internal.SetGlobalTracer(&internal.NoopTracer{})
 	t.Run("64-bit-trace-id", func(t *testing.T) {
 		assert := assert.New(t)
+		os.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
+		defer os.Unsetenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED")
 		opts := []StartSpanOption{
 			WithSpanID(987654),
 		}
@@ -730,8 +732,7 @@ func TestTracerStartSpanOptions128(t *testing.T) {
 	})
 	t.Run("128-bit-trace-id", func(t *testing.T) {
 		assert := assert.New(t)
-		// Enable 128 bit trace ids
-		t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "true")
+		// 128-bit trace ids are enabled by default.
 		opts128 := []StartSpanOption{
 			WithSpanID(987654),
 			StartTime(time.Unix(123456, 0)),
@@ -1044,8 +1045,9 @@ func TestNewSpanChild(t *testing.T) {
 
 func testNewSpanChild(t *testing.T, is128 bool) {
 	t.Run(fmt.Sprintf("TestNewChildSpan(is128=%t)", is128), func(*testing.T) {
-		if is128 {
-			t.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "true")
+		if !is128 {
+			os.Setenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED", "false")
+			defer os.Unsetenv("DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED")
 		}
 		assert := assert.New(t)