diff --git a/internal/ingress/controller/controller.go b/internal/ingress/controller/controller.go
index ea9c06a61..af59bf7f8 100644
--- a/internal/ingress/controller/controller.go
+++ b/internal/ingress/controller/controller.go
@@ -131,7 +131,13 @@ func (n *NGINXController) syncIngress(interface{}) error {
 	upstreams, servers := n.getBackendServers(ings)
 	var passUpstreams []*ingress.SSLPassthroughBackend
 
+	hosts := sets.NewString()
+
 	for _, server := range servers {
+		if !hosts.Has(server.Hostname) {
+			hosts.Insert(server.Hostname)
+		}
+
 		if !server.SSLPassthrough {
 			continue
 		}
@@ -184,6 +190,8 @@ func (n *NGINXController) syncIngress(interface{}) error {
 			return err
 		}
 
+		n.metricCollector.SetHosts(hosts)
+
 		glog.Infof("Backend successfully reloaded.")
 		n.metricCollector.ConfigSuccess(hash, true)
 		n.metricCollector.IncReloadCount()
diff --git a/internal/ingress/controller/nginx_test.go b/internal/ingress/controller/nginx_test.go
index 969ef2a57..e2a815c85 100644
--- a/internal/ingress/controller/nginx_test.go
+++ b/internal/ingress/controller/nginx_test.go
@@ -17,7 +17,6 @@ limitations under the License.
 package controller
 
 import (
-	"encoding/json"
 	"io"
 	"io/ioutil"
 	"net"
@@ -26,7 +25,9 @@ import (
 	"strings"
 	"testing"
 
+	jsoniter "github.com/json-iterator/go"
 	apiv1 "k8s.io/api/core/v1"
+
 	"k8s.io/ingress-nginx/internal/ingress"
 )
 
@@ -241,7 +242,7 @@ func TestConfigureCertificates(t *testing.T) {
 			t.Fatal(err)
 		}
 		var postedServers []ingress.Server
-		err = json.Unmarshal(b, &postedServers)
+		err = jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(b, &postedServers)
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/internal/ingress/controller/template/template_test.go b/internal/ingress/controller/template/template_test.go
index 5e489d867..c65ad0ee9 100644
--- a/internal/ingress/controller/template/template_test.go
+++ b/internal/ingress/controller/template/template_test.go
@@ -17,7 +17,6 @@ limitations under the License.
 package template
 
 import (
-	"encoding/json"
 	"io/ioutil"
 	"net"
 	"os"
@@ -29,6 +28,7 @@ import (
 	"encoding/base64"
 	"fmt"
 
+	jsoniter "github.com/json-iterator/go"
 	"k8s.io/ingress-nginx/internal/file"
 	"k8s.io/ingress-nginx/internal/ingress"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/authreq"
@@ -518,7 +518,7 @@ func TestTemplateWithData(t *testing.T) {
 		t.Error("unexpected error reading json file: ", err)
 	}
 	var dat config.TemplateConfig
-	if err := json.Unmarshal(data, &dat); err != nil {
+	if err := jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(data, &dat); err != nil {
 		t.Errorf("unexpected error unmarshalling json: %v", err)
 	}
 	if dat.ListenPorts == nil {
@@ -565,7 +565,7 @@ func BenchmarkTemplateWithData(b *testing.B) {
 		b.Error("unexpected error reading json file: ", err)
 	}
 	var dat config.TemplateConfig
-	if err := json.Unmarshal(data, &dat); err != nil {
+	if err := jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(data, &dat); err != nil {
 		b.Errorf("unexpected error unmarshalling json: %v", err)
 	}
 
diff --git a/internal/ingress/metric/main.go b/internal/ingress/metric/main.go
index c63c89156..df763b679 100644
--- a/internal/ingress/metric/main.go
+++ b/internal/ingress/metric/main.go
@@ -22,6 +22,8 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 
+	"k8s.io/apimachinery/pkg/util/sets"
+
 	"k8s.io/ingress-nginx/internal/ingress"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/class"
 	"k8s.io/ingress-nginx/internal/ingress/metric/collectors"
@@ -38,6 +40,9 @@ type Collector interface {
 
 	SetSSLExpireTime([]*ingress.Server)
 
+	// SetHosts sets the hostnames that are being served by the ingress controller
+	SetHosts(sets.String)
+
 	Start()
 	Stop()
 }
@@ -138,3 +143,7 @@ func (c *collector) Stop() {
 func (c *collector) SetSSLExpireTime(servers []*ingress.Server) {
 	c.ingressController.SetSSLExpireTime(servers)
 }
+
+func (c *collector) SetHosts(hosts sets.String) {
+	c.socket.SetHosts(hosts)
+}
diff --git a/test/e2e/annotations/influxdb.go b/test/e2e/annotations/influxdb.go
index 0adfd4657..1286bdc93 100644
--- a/test/e2e/annotations/influxdb.go
+++ b/test/e2e/annotations/influxdb.go
@@ -18,12 +18,12 @@ package annotations
 
 import (
 	"bytes"
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"os/exec"
 	"time"
 
+	jsoniter "github.com/json-iterator/go"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	"github.com/parnurzeal/gorequest"
@@ -90,7 +90,7 @@ var _ = framework.IngressNginxDescribe("Annotations - influxdb", func() {
 			Expect(err).NotTo(HaveOccurred())
 
 			var results map[string][]map[string]interface{}
-			json.Unmarshal([]byte(measurements), &results)
+			jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal([]byte(measurements), &results)
 
 			Expect(len(measurements)).ShouldNot(Equal(0))
 			for _, elem := range results["results"] {