chore(ursrv): separate calculation from serving metrics

cmd/infra/ursrv/serve/serve.go

@@ -33,6 +33,7 @@ import (
 	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/geoip"
 	"github.com/syncthing/syncthing/lib/ur/contract"
+	"github.com/thejerf/suture/v4"
 )
 
 type CLI struct {
@@ -187,7 +188,12 @@ func (cli *CLI) Run() error {
 	// New external metrics endpoint accepts reports from clients and serves
 	// aggregated usage reporting metrics.
 
+	main := suture.NewSimple("main")
+	main.ServeBackground(context.Background())
+
 	ms := newMetricsSet(srv)
+	main.Add(ms)
+
 	reg := prometheus.NewRegistry()
 	reg.MustRegister(ms)
 
@@ -198,7 +204,7 @@ func (cli *CLI) Run() error {
 
 	metricsSrv := http.Server{
 		ReadTimeout:  5 * time.Second,
-		WriteTimeout: 15 * time.Second,
+		WriteTimeout: 60 * time.Second,
 		Handler:      mux,
 	}
 
@@ -227,6 +233,11 @@ func (cli *CLI) downloadDumpFile(blobs blob.Store) error {
 }
 
 func (cli *CLI) saveDumpFile(srv *server, blobs blob.Store) error {
+	t0 := time.Now()
+	defer func() {
+		metricsWriteSecondsLast.Set(float64(time.Since(t0)))
+	}()
+
 	fd, err := os.Create(cli.DumpFile + ".tmp")
 	if err != nil {
 		return fmt.Errorf("creating dump file: %w", err)
@@ -245,9 +256,10 @@ func (cli *CLI) saveDumpFile(srv *server, blobs blob.Store) error {
 	if err := os.Rename(cli.DumpFile+".tmp", cli.DumpFile); err != nil {
 		return fmt.Errorf("renaming dump file: %w", err)
 	}
-	slog.Info("Dump file saved")
+	slog.Info("Dump file saved", "d", time.Since(t0).String())
 
 	if blobs != nil {
+		t1 := time.Now()
 		key := fmt.Sprintf("reports-%s.jsons.gz", time.Now().UTC().Format("2006-01-02"))
 		fd, err := os.Open(cli.DumpFile)
 		if err != nil {
@@ -257,7 +269,7 @@ func (cli *CLI) saveDumpFile(srv *server, blobs blob.Store) error {
 			return fmt.Errorf("uploading dump file: %w", err)
 		}
 		_ = fd.Close()
-		slog.Info("Dump file uploaded")
+		slog.Info("Dump file uploaded", "d", time.Since(t1).String())
 	}
 
 	return nil
@@ -388,6 +400,7 @@ func (s *server) save(w io.Writer) error {
 }
 
 func (s *server) load(r io.Reader) {
+	t0 := time.Now()
 	dec := json.NewDecoder(r)
 	s.reports.Clear()
 	for {
@@ -400,7 +413,7 @@ func (s *server) load(r io.Reader) {
 		}
 		s.addReport(&rep)
 	}
-	slog.Info("Loaded reports", "count", s.reports.Size())
+	slog.Info("Loaded reports", "count", s.reports.Size(), "d", time.Since(t0).String())
 }
 
 var (