atmost working example

cmd/simulator/main.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"os/signal"
+	"strconv"
+	"sync/atomic"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+
+	"git.loyso.art/frx/devsim/internal/entities"
+	"git.loyso.art/frx/devsim/internal/interconnect/collector"
+)
+
+var requestsDone = atomic.Uint64{}
+
+func requestReporter(ctx context.Context) {
+	ticker := time.Tick(time.Second)
+	for {
+		select {
+		case <-ticker:
+		case <-ctx.Done():
+			return
+		}
+		requests := requestsDone.Swap(0)
+		log.Printf("rps: %d", requests)
+	}
+}
+
+func main() {
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer cancel()
+
+	dstAddr := os.Getenv("DEVSIM_HTTP_ADDR")
+	deviceCountStr := os.Getenv("DEVSIM_DEVICE_COUNT")
+	delayStr := os.Getenv("DEVSIM_REQUEST_DELAY")
+
+	deviceCount, err := strconv.Atoi(deviceCountStr)
+	if err != nil {
+		log.Fatalf("parsing device count: %v", err)
+	}
+
+	if dstAddr == "" {
+		log.Fatal("no destination address provided")
+	}
+
+	delay, err := time.ParseDuration(delayStr)
+	if err != nil {
+		log.Fatalf("parsing delay duration: %v", err)
+	}
+
+	log.Printf("running application with settings: destination=%s device_count=%d delay=%s", dstAddr, deviceCount, delay)
+
+	client, err := collector.New(dstAddr)
+	if err != nil {
+		log.Fatalf("unable to create collector http client: %v", err)
+	}
+
+	eg, egctx := errgroup.WithContext(ctx)
+
+	eg.Go(func() error {
+		requestReporter(egctx)
+		return nil
+	})
+
+	for i := 0; i < deviceCount; i++ {
+		dh := newDeviceHandler(i+1, delay, client)
+		eg.Go(func() error {
+			dh.loop(egctx)
+			return nil
+		})
+	}
+
+	err = eg.Wait()
+	if err != nil {
+		log.Printf("error during execution: %v", err)
+		cancel()
+	}
+}
+
+type deviceHandler struct {
+	stats  entities.DeviceStatistics
+	client collector.Client
+	delay  time.Duration
+}
+
+func newDeviceHandler(id int, delay time.Duration, client collector.Client) *deviceHandler {
+	deviceID := entities.DeviceID(strconv.Itoa(id))
+	dh := deviceHandler{
+		delay:  delay,
+		client: client,
+	}
+	dh.stats.ID = deviceID
+
+	return &dh
+}
+
+func (h *deviceHandler) loop(ctx context.Context) {
+	failedCount := 0
+
+	for {
+		start := time.Now()
+
+		h.stats.IncomingTrafficBytes++
+		h.stats.OutgoingTrafficBytes++
+
+		h.stats.WriteRPS = (h.stats.WriteRPS + 2) % 255
+		h.stats.ReadRPS = (h.stats.ReadRPS + 1) % 255
+		h.stats.IncomingRPS = h.stats.WriteRPS + h.stats.ReadRPS
+
+		err := h.client.Upsert(ctx, h.stats)
+		if err != nil {
+			log.Printf("%q: unable to upsert metrics: %v", h.stats.ID, err)
+			failedCount++
+			if failedCount > 10 {
+				log.Println("too much fails, exiting")
+				return
+			}
+
+			continue
+		}
+
+		requestsDone.Add(1)
+
+		failedCount = 0
+		elapsed := time.Since(start)
+		left := h.delay - elapsed
+
+		if left > 0 {
+			select {
+			case <-ctx.Done():
+				return
+			case <-time.After(left):
+				continue
+			}
+		} else {
+			if ctx.Err() != nil {
+				return
+			}
+		}
+	}
+}