diff --git a/pkg/apis/flagger/v1alpha3/types.go b/pkg/apis/flagger/v1alpha3/types.go
index c356d8a04..e2138e453 100755
--- a/pkg/apis/flagger/v1alpha3/types.go
+++ b/pkg/apis/flagger/v1alpha3/types.go
@@ -136,7 +136,7 @@ type CanaryWebhook struct {
 type CanaryWebhookPayload struct {
 	Name      string             `json:"name"`
 	Namespace string             `json:"namespace"`
-	Metadata  *map[string]string `json:"metadata,omitempty"`
+	Metadata  map[string]string `json:"metadata,omitempty"`
 }
 
 // GetProgressDeadlineSeconds returns the progress deadline (default 600s)
diff --git a/pkg/apis/flagger/v1alpha3/zz_generated.deepcopy.go b/pkg/apis/flagger/v1alpha3/zz_generated.deepcopy.go
index 34b134d7a..f3e090fe8 100644
--- a/pkg/apis/flagger/v1alpha3/zz_generated.deepcopy.go
+++ b/pkg/apis/flagger/v1alpha3/zz_generated.deepcopy.go
@@ -234,13 +234,9 @@ func (in *CanaryWebhookPayload) DeepCopyInto(out *CanaryWebhookPayload) {
 	*out = *in
 	if in.Metadata != nil {
 		in, out := &in.Metadata, &out.Metadata
-		*out = new(map[string]string)
-		if **in != nil {
-			in, out := *in, *out
-			*out = make(map[string]string, len(*in))
-			for key, val := range *in {
-				(*out)[key] = val
-			}
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
 		}
 	}
 	return
diff --git a/pkg/controller/scheduler.go b/pkg/controller/scheduler.go
index 0fd9f1c42..b13da42e6 100644
--- a/pkg/controller/scheduler.go
+++ b/pkg/controller/scheduler.go
@@ -2,6 +2,7 @@ package controller
 
 import (
 	"fmt"
+	"strings"
 	"time"
 
 	flaggerv1 "github.com/stefanprodan/flagger/pkg/apis/flagger/v1alpha3"
@@ -336,12 +337,27 @@ func (c *Controller) hasCanaryRevisionChanged(cd *flaggerv1.Canary) bool {
 }
 
 func (c *Controller) analyseCanary(r *flaggerv1.Canary) bool {
+	// run external checks
+	for _, webhook := range r.Spec.CanaryAnalysis.Webhooks {
+		err := CallWebhook(r.Name, r.Namespace, webhook)
+		if err != nil {
+			c.recordEventWarningf(r, "Halt %s.%s advancement external check %s failed %v",
+				r.Name, r.Namespace, webhook.Name, err)
+			return false
+		}
+	}
+
 	// run metrics checks
 	for _, metric := range r.Spec.CanaryAnalysis.Metrics {
 		if metric.Name == "istio_requests_total" {
 			val, err := c.observer.GetDeploymentCounter(r.Spec.TargetRef.Name, r.Namespace, metric.Name, metric.Interval)
 			if err != nil {
-				c.recordEventErrorf(r, "Metrics server %s query failed: %v", c.observer.metricsServer, err)
+				if strings.Contains(err.Error(), "no values found"){
+					c.recordEventWarningf(r, "Halt advancement no values found for metric %s probably %s.%s is not receiving traffic",
+						metric.Name, r.Spec.TargetRef.Name, r.Namespace)
+				}else {
+					c.recordEventErrorf(r, "Metrics server %s query failed: %v", c.observer.metricsServer, err)
+				}
 				return false
 			}
 			if float64(metric.Threshold) > val {
@@ -366,15 +382,5 @@ func (c *Controller) analyseCanary(r *flaggerv1.Canary) bool {
 		}
 	}
 
-	// run external checks
-	for _, webhook := range r.Spec.CanaryAnalysis.Webhooks {
-		err := CallWebhook(r.Name, r.Namespace, webhook)
-		if err != nil {
-			c.recordEventWarningf(r, "Halt %s.%s advancement external check %s failed %v",
-				r.Name, r.Namespace, webhook.Name, err)
-			return false
-		}
-	}
-
 	return true
 }
diff --git a/pkg/controller/webhook.go b/pkg/controller/webhook.go
index f9c99ef0e..7c0322b4d 100644
--- a/pkg/controller/webhook.go
+++ b/pkg/controller/webhook.go
@@ -19,7 +19,10 @@ func CallWebhook(name string, namepace string, w flaggerv1.CanaryWebhook) error
 	payload := flaggerv1.CanaryWebhookPayload{
 		Name:      name,
 		Namespace: namepace,
-		Metadata:  w.Metadata,
+	}
+
+	if w.Metadata != nil {
+		payload.Metadata = *w.Metadata
 	}
 
 	payloadBin, err := json.Marshal(payload)