internal/apps: Add two new apps (#2868)

Co-authored-by: Nick Ripley <nick.ripley@datadoghq.com>

internal/apps/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.22
+FROM golang:1.23
 COPY . /dd-trace-go
 WORKDIR /dd-trace-go/internal/apps
 # -t will download all dependencies, including test dependencies

internal/apps/apps.go

@@ -25,9 +25,11 @@ type Config struct {
 	// default we configure non-stop execution tracing for the test apps unless
 	// a DD_PROFILING_EXECUTION_TRACE_PERIOD env is set or this option is true.
 	DisableExecutionTracing bool
+
+	httpAddr net.Addr
 }
 
-func (c Config) RunHTTP(handler func() http.Handler) {
+func (c *Config) RunHTTP(handler func() http.Handler) {
 	// Parse common test app flags
 	var (
 		httpF   = flag.String("http", "localhost:8080", "HTTP addr to listen on.")
@@ -69,6 +71,7 @@ func (c Config) RunHTTP(handler func() http.Handler) {
 		log.Fatalf("failed to listen: %s", err)
 	}
 	defer l.Close()
+	c.httpAddr = l.Addr()
 	log.Printf("Listening on: http://%s", *httpF)
 	// handler is a func, because if we create a traced handler before starting
 	// the tracer, the service name will default to http.router.
@@ -79,3 +82,7 @@ func (c Config) RunHTTP(handler func() http.Handler) {
 	<-ctx.Done()
 	log.Printf("Received interrupt, shutting down")
 }
+
+func (c Config) HTTPAddr() net.Addr {
+	return c.httpAddr
+}

internal/apps/gc-overhead/main.go

@@ -0,0 +1,177 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2023 Datadog, Inc.
+
+// gc-overhead implements a http service that demonstrates high GC overhead. The
+// primary use case is to take screenshots of CPU and Memory profiles for blog
+// posts. The code is intentionally inefficient, but should produce plausible
+// FlameGraphs. Loop and data sizes are chosen so that the hotspots in the CPU
+// profile, the Allocated Memory Profile, and the Heap Live Objects profile are
+// different.
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"maps"
+	"math"
+	"math/rand/v2"
+	"net/http"
+	"runtime/debug"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/DataDog/dd-trace-go/internal/apps"
+	httptrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/net/http"
+)
+
+func main() {
+	// Initialize fake data
+	initFakeData()
+
+	// Experimentally determined value to keep GC overhead around 30%.
+	debug.SetGCPercent(35)
+
+	// Start app
+	app := apps.Config{}
+	app.RunHTTP(func() http.Handler {
+		mux := httptrace.NewServeMux()
+		mux.HandleFunc("/vehicles/update_location", VehiclesUpdateLocationHandler)
+		mux.HandleFunc("/vehicles/list", VehiclesListHandler)
+		return mux
+	})
+}
+
+func VehiclesUpdateLocationHandler(w http.ResponseWriter, r *http.Request) {
+	load := int(sineLoad() * 2e5)
+	for i := 0; i < load; i++ {
+		u := &VehicleLocationUpdate{}
+		data := fakeData.vehicleLocationUpdates[i%len(fakeData.vehicleLocationUpdates)]
+		if err := parseVehicleLocationUpdate(data, u); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		store.Update(u)
+	}
+	w.Write([]byte("ok"))
+}
+
+func parseVehicleLocationUpdate(data []byte, u *VehicleLocationUpdate) error {
+	return json.Unmarshal(data, u)
+}
+
+func VehiclesListHandler(w http.ResponseWriter, r *http.Request) {
+	w.Write(renderVehiclesList().Bytes())
+}
+
+func renderVehiclesList() *bytes.Buffer {
+	buf := &bytes.Buffer{}
+	list := store.List()
+	load := sineLoad() * float64(len(list))
+	list = list[0:int(load)]
+	for _, v := range list {
+		fmt.Fprintf(buf, "%s: %v\n", v.ID, v.History)
+	}
+	return buf
+}
+
+var fakeData struct {
+	vehicleLocationUpdates [1000][]byte
+}
+
+var store = MemoryStore{}
+
+func initFakeData() {
+	for i := 0; i < len(fakeData.vehicleLocationUpdates); i++ {
+		update := VehicleLocationUpdate{
+			ID: fmt.Sprintf("vehicle-%d", i),
+			Position: Position{
+				Longitude: rand.Float64()*180 - 90,
+				Latitude:  rand.Float64()*360 - 180,
+			},
+		}
+		fakeData.vehicleLocationUpdates[i], _ = json.Marshal(update)
+	}
+}
+
+type MemoryStore struct {
+	mu       sync.RWMutex
+	vehicles map[string]*Vehicle
+}
+
+func (m *MemoryStore) Update(u *VehicleLocationUpdate) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.vehicles == nil {
+		m.vehicles = make(map[string]*Vehicle)
+	}
+
+	vehicle, ok := m.vehicles[u.ID]
+	if !ok {
+		vehicle = NewVehicle(u.ID)
+		m.vehicles[u.ID] = vehicle
+	}
+	vehicle.History = append(vehicle.History, &u.Position)
+	const historyLimit = 2000
+	if len(vehicle.History) > historyLimit {
+		// Keep only the last positions
+		copy(vehicle.History, vehicle.History[len(vehicle.History)-historyLimit:])
+		vehicle.History = vehicle.History[:historyLimit]
+	}
+}
+
+func NewVehicle(id string) *Vehicle {
+	return &Vehicle{ID: id, Data: make([]byte, 1024*1024)}
+}
+
+func (m *MemoryStore) List() (vehicles []*Vehicle) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	for _, key := range slices.Sorted(maps.Keys(m.vehicles)) {
+		vehicles = append(vehicles, m.vehicles[key].Copy())
+	}
+	return vehicles
+}
+
+type Position struct {
+	Longitude float64
+	Latitude  float64
+}
+
+type VehicleLocationUpdate struct {
+	ID       string
+	Position Position
+}
+
+type Vehicle struct {
+	ID      string
+	History []*Position
+	Data    []byte
+}
+
+func (v *Vehicle) Copy() *Vehicle {
+	history := make([]*Position, len(v.History))
+	copy(history, v.History)
+	return &Vehicle{
+		ID:      v.ID,
+		History: history,
+	}
+}
+
+// sineLoad returns a value between 0 and 1 that varies sinusoidally over time.
+func sineLoad() float64 {
+	period := 5 * time.Minute
+	// Get the current time in seconds since Unix epoch
+	currentTime := time.Now().UnixNano()
+	// Compute the phase of the sine wave, current time modulo period
+	phase := float64(currentTime) / float64(period) * 2 * math.Pi
+	// Generate the sine wave value (-1 to 1)
+	sineValue := math.Sin(phase)
+	// Normalize the sine wave value to be between 0 and 1
+	return (sineValue + 1) * 0.5
+}

internal/apps/go.mod

@@ -1,6 +1,6 @@
 module github.com/DataDog/dd-trace-go/internal/apps
 
-go 1.22.0
+go 1.23.0
 
 require (
 	golang.org/x/sync v0.7.0

internal/apps/scenario_test.go

@@ -66,6 +66,42 @@ func TestScenario(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("gc-overhead", func(t *testing.T) {
+		scenarios := []struct {
+			version   string
+			endpoints []string
+		}{
+			{"v1", []string{"/vehicles/update_location", "/vehicles/list"}},
+		}
+		for _, s := range scenarios {
+			t.Run(s.version, func(t *testing.T) {
+				lc := newLaunchConfig(t)
+				lc.Version = s.version
+				process := lc.Launch(t)
+				defer process.Stop(t)
+				wc.HitEndpoints(t, process, s.endpoints...)
+			})
+		}
+	})
+
+	t.Run("worker-pool-bottleneck", func(t *testing.T) {
+		scenarios := []struct {
+			version   string
+			endpoints []string
+		}{
+			{"v1", []string{"/queue/push"}},
+		}
+		for _, s := range scenarios {
+			t.Run(s.version, func(t *testing.T) {
+				lc := newLaunchConfig(t)
+				lc.Version = s.version
+				process := lc.Launch(t)
+				defer process.Stop(t)
+				wc.HitEndpoints(t, process, s.endpoints...)
+			})
+		}
+	})
 }
 
 func newWorkloadConfig(t *testing.T) (wc workloadConfig) {
@@ -152,6 +188,13 @@ func appName(t *testing.T) string {
 }
 
 func serviceName(t *testing.T) string {
+	// Allow overriding the service name via env var
+	ddService := os.Getenv("DD_SERVICE")
+	if ddService != "" {
+		return ddService
+	}
+
+	// Otherwise derive the service name from the test name
 	return "dd-trace-go/" + strings.Join(strings.Split(t.Name(), "/")[1:], "/")
 }