diff --git a/app/vmselect/main.go b/app/vmselect/main.go
index 255e387ee3..701a2f4225 100644
--- a/app/vmselect/main.go
+++ b/app/vmselect/main.go
@@ -111,6 +111,7 @@ var (
 )
 
 func requestHandler(w http.ResponseWriter, r *http.Request) bool {
+	startTime := time.Now()
 	// Limit the number of concurrent queries.
 	select {
 	case concurrencyCh <- struct{}{}:
@@ -155,23 +156,23 @@ func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 	}
 	switch p.Prefix {
 	case "select":
-		return selectHandler(w, r, p, at)
+		return selectHandler(startTime, w, r, p, at)
 	case "delete":
-		return deleteHandler(w, r, p, at)
+		return deleteHandler(startTime, w, r, p, at)
 	default:
 		// This is not our link
 		return false
 	}
 }
 
-func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, at *auth.Token) bool {
+func selectHandler(startTime time.Time, w http.ResponseWriter, r *http.Request, p *httpserver.Path, at *auth.Token) bool {
 	if strings.HasPrefix(p.Suffix, "prometheus/api/v1/label/") {
 		s := p.Suffix[len("prometheus/api/v1/label/"):]
 		if strings.HasSuffix(s, "/values") {
 			labelValuesRequests.Inc()
 			labelName := s[:len(s)-len("/values")]
 			httpserver.EnableCORS(w, r)
-			if err := prometheus.LabelValuesHandler(at, labelName, w, r); err != nil {
+			if err := prometheus.LabelValuesHandler(startTime, at, labelName, w, r); err != nil {
 				labelValuesErrors.Inc()
 				sendPrometheusError(w, r, err)
 				return true
@@ -184,7 +185,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/query":
 		queryRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.QueryHandler(at, w, r); err != nil {
+		if err := prometheus.QueryHandler(startTime, at, w, r); err != nil {
 			queryErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -193,7 +194,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/query_range":
 		queryRangeRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.QueryRangeHandler(at, w, r); err != nil {
+		if err := prometheus.QueryRangeHandler(startTime, at, w, r); err != nil {
 			queryRangeErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -202,7 +203,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/series":
 		seriesRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.SeriesHandler(at, w, r); err != nil {
+		if err := prometheus.SeriesHandler(startTime, at, w, r); err != nil {
 			seriesErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -211,7 +212,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/series/count":
 		seriesCountRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.SeriesCountHandler(at, w, r); err != nil {
+		if err := prometheus.SeriesCountHandler(startTime, at, w, r); err != nil {
 			seriesCountErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -220,7 +221,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/labels":
 		labelsRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.LabelsHandler(at, w, r); err != nil {
+		if err := prometheus.LabelsHandler(startTime, at, w, r); err != nil {
 			labelsErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -229,7 +230,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	case "prometheus/api/v1/labels/count":
 		labelsCountRequests.Inc()
 		httpserver.EnableCORS(w, r)
-		if err := prometheus.LabelsCountHandler(at, w, r); err != nil {
+		if err := prometheus.LabelsCountHandler(startTime, at, w, r); err != nil {
 			labelsCountErrors.Inc()
 			sendPrometheusError(w, r, err)
 			return true
@@ -237,7 +238,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 		return true
 	case "prometheus/api/v1/export":
 		exportRequests.Inc()
-		if err := prometheus.ExportHandler(at, w, r); err != nil {
+		if err := prometheus.ExportHandler(startTime, at, w, r); err != nil {
 			exportErrors.Inc()
 			httpserver.Errorf(w, "error in %q: %s", r.URL.Path, err)
 			return true
@@ -245,7 +246,7 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 		return true
 	case "prometheus/federate":
 		federateRequests.Inc()
-		if err := prometheus.FederateHandler(at, w, r); err != nil {
+		if err := prometheus.FederateHandler(startTime, at, w, r); err != nil {
 			federateErrors.Inc()
 			httpserver.Errorf(w, "error in %q: %s", r.URL.Path, err)
 			return true
@@ -274,11 +275,11 @@ func selectHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, a
 	}
 }
 
-func deleteHandler(w http.ResponseWriter, r *http.Request, p *httpserver.Path, at *auth.Token) bool {
+func deleteHandler(startTime time.Time, w http.ResponseWriter, r *http.Request, p *httpserver.Path, at *auth.Token) bool {
 	switch p.Suffix {
 	case "prometheus/api/v1/admin/tsdb/delete_series":
 		deleteRequests.Inc()
-		if err := prometheus.DeleteHandler(at, r); err != nil {
+		if err := prometheus.DeleteHandler(startTime, at, r); err != nil {
 			deleteErrors.Inc()
 			httpserver.Errorf(w, "error in %q: %s", r.URL.Path, err)
 			return true
diff --git a/app/vmselect/prometheus/prometheus.go b/app/vmselect/prometheus/prometheus.go
index e6f3b125a6..4f4ce5bf6c 100644
--- a/app/vmselect/prometheus/prometheus.go
+++ b/app/vmselect/prometheus/prometheus.go
@@ -39,8 +39,7 @@ var (
 const defaultStep = 5 * 60 * 1000
 
 // FederateHandler implements /federate . See https://prometheus.io/docs/prometheus/latest/federation/
-func FederateHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func FederateHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse request form values: %s", err)
@@ -116,8 +115,7 @@ func FederateHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) err
 var federateDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/federate"}`)
 
 // ExportHandler exports data in raw format from /api/v1/export.
-func ExportHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func ExportHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse request form values: %s", err)
@@ -215,8 +213,7 @@ func exportHandler(at *auth.Token, w http.ResponseWriter, matches []string, star
 // DeleteHandler processes /api/v1/admin/tsdb/delete_series prometheus API request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#delete-series
-func DeleteHandler(at *auth.Token, r *http.Request) error {
-	startTime := time.Now()
+func DeleteHandler(startTime time.Time, at *auth.Token, r *http.Request) error {
 	if err := r.ParseForm(); err != nil {
 		return fmt.Errorf("cannot parse request form values: %s", err)
 	}
@@ -288,8 +285,7 @@ var httpClient = &http.Client{
 // LabelValuesHandler processes /api/v1/label/<labelName>/values request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#querying-label-values
-func LabelValuesHandler(at *auth.Token, labelName string, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func LabelValuesHandler(startTime time.Time, at *auth.Token, labelName string, w http.ResponseWriter, r *http.Request) error {
 	deadline := getDeadlineForQuery(r)
 
 	if err := r.ParseForm(); err != nil {
@@ -392,8 +388,7 @@ func labelValuesWithMatches(at *auth.Token, labelName string, matches []string,
 var labelValuesDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/v1/label/{}/values"}`)
 
 // LabelsCountHandler processes /api/v1/labels/count request.
-func LabelsCountHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func LabelsCountHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	deadline := getDeadlineForQuery(r)
 	labelEntries, isPartial, err := netstorage.GetLabelEntries(at, deadline)
 	if err != nil {
@@ -414,8 +409,7 @@ var labelsCountDuration = metrics.NewSummary(`vm_request_duration_seconds{path="
 // LabelsHandler processes /api/v1/labels request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#getting-label-names
-func LabelsHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func LabelsHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	deadline := getDeadlineForQuery(r)
 
 	if err := r.ParseForm(); err != nil {
@@ -510,8 +504,7 @@ func labelsWithMatches(at *auth.Token, matches []string, start, end int64, deadl
 var labelsDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/v1/labels"}`)
 
 // SeriesCountHandler processes /api/v1/series/count request.
-func SeriesCountHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func SeriesCountHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	deadline := getDeadlineForQuery(r)
 	n, isPartial, err := netstorage.GetSeriesCount(at, deadline)
 	if err != nil {
@@ -532,8 +525,7 @@ var seriesCountDuration = metrics.NewSummary(`vm_request_duration_seconds{path="
 // SeriesHandler processes /api/v1/series request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#finding-series-by-label-matchers
-func SeriesHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func SeriesHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 
 	if err := r.ParseForm(); err != nil {
@@ -613,8 +605,7 @@ var seriesDuration = metrics.NewSummary(`vm_request_duration_seconds{path="/api/
 // QueryHandler processes /api/v1/query request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#instant-queries
-func QueryHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func QueryHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 
 	query := r.FormValue("query")
@@ -728,8 +719,7 @@ func parsePositiveDuration(s string, step int64) (int64, error) {
 // QueryRangeHandler processes /api/v1/query_range request.
 //
 // See https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries
-func QueryRangeHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error {
-	startTime := time.Now()
+func QueryRangeHandler(startTime time.Time, at *auth.Token, w http.ResponseWriter, r *http.Request) error {
 	ct := currentTime()
 
 	query := r.FormValue("query")