diff --git a/cmd/agent_auditor.go b/cmd/agent_auditor.go
index 603dc8a6a..2e24a5446 100644
--- a/cmd/agent_auditor.go
+++ b/cmd/agent_auditor.go
@@ -21,6 +21,7 @@ import (
 	"github.com/bbva/qed/gossip/auditor"
 	"github.com/bbva/qed/gossip/member"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/util"
 )
 
@@ -57,8 +58,8 @@ func newAgentAuditorCommand(ctx *cmdContext, config gossip.Config, agentPreRun f
 			if err != nil {
 				log.Fatalf("Failed to start the QED monitor: %v", err)
 			}
-
-			agent, err := gossip.NewAgent(&config, []gossip.Processor{auditor})
+			metricsServer := metrics.NewServer(config.MetricsAddr)
+			agent, err := gossip.NewAgent(&config, []gossip.Processor{auditor}, metricsServer)
 			if err != nil {
 				log.Fatalf("Failed to start the QED auditor: %v", err)
 			}
diff --git a/cmd/agent_monitor.go b/cmd/agent_monitor.go
index a823ef7c6..fda4db0f6 100644
--- a/cmd/agent_monitor.go
+++ b/cmd/agent_monitor.go
@@ -21,6 +21,7 @@ import (
 	"github.com/bbva/qed/gossip/member"
 	"github.com/bbva/qed/gossip/monitor"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/util"
 )
 
@@ -57,8 +58,8 @@ func newAgentMonitorCommand(ctx *cmdContext, config gossip.Config, agentPreRun f
 			if err != nil {
 				log.Fatalf("Failed to start the QED monitor: %v", err)
 			}
-
-			agent, err := gossip.NewAgent(&config, []gossip.Processor{monitor})
+			metricsServer := metrics.NewServer(config.MetricsAddr)
+			agent, err := gossip.NewAgent(&config, []gossip.Processor{monitor}, metricsServer)
 			if err != nil {
 				log.Fatalf("Failed to start the QED monitor: %v", err)
 			}
diff --git a/cmd/agent_publisher.go b/cmd/agent_publisher.go
index cfe16e4ee..e2c40680f 100644
--- a/cmd/agent_publisher.go
+++ b/cmd/agent_publisher.go
@@ -21,6 +21,7 @@ import (
 	"github.com/bbva/qed/gossip/member"
 	"github.com/bbva/qed/gossip/publisher"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/util"
 )
 
@@ -56,8 +57,8 @@ func newAgentPublisherCommand(ctx *cmdContext, config gossip.Config, agentPreRun
 			if err != nil {
 				log.Fatalf("Failed to start the QED publisher: %v", err)
 			}
-
-			agent, err := gossip.NewAgent(&config, []gossip.Processor{publisher})
+			metricsServer := metrics.NewServer(config.MetricsAddr)
+			agent, err := gossip.NewAgent(&config, []gossip.Processor{publisher}, metricsServer)
 			if err != nil {
 				log.Fatalf("Failed to start the QED publisher: %v", err)
 			}
diff --git a/gossip/agent.go b/gossip/agent.go
index 2a9dc6f32..13e349ab6 100644
--- a/gossip/agent.go
+++ b/gossip/agent.go
@@ -24,6 +24,7 @@ import (
 	"github.com/bbva/qed/gossip/member"
 	"github.com/bbva/qed/hashing"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/protocol"
 	"github.com/coocood/freecache"
 	"github.com/hashicorp/memberlist"
@@ -38,7 +39,7 @@ type Agent struct {
 	config *Config
 	Self   *member.Peer
 
-	metricsServer *metricsServer
+	metricsServer *metrics.Server
 
 	memberlist *memberlist.Memberlist
 	broadcasts *memberlist.TransmitLimitedQueue
@@ -55,11 +56,11 @@ type Agent struct {
 	quit chan bool
 }
 
-func NewAgent(conf *Config, p []Processor) (agent *Agent, err error) {
+func NewAgent(conf *Config, p []Processor, m *metrics.Server) (agent *Agent, err error) {
 	log.Infof("New agent %s\n", conf.NodeName)
 	agent = &Agent{
 		config:        conf,
-		metricsServer: newMetricsServer(conf.MetricsAddr),
+		metricsServer: m,
 		Topology:      NewTopology(),
 		processors:    p,
 		processed:     freecache.NewCache(1 << 20),
@@ -134,11 +135,11 @@ func (a *Agent) ChTimedSend(batch *protocol.BatchSnapshots, ch chan *protocol.Ba
 func (a *Agent) start() {
 
 	for _, p := range a.processors {
-		p.RegisterMetrics(a.metricsServer.registry)
+		p.RegisterMetrics(a.metricsServer)
 	}
 
 	go func() {
-		a.metricsServer.start()
+		a.metricsServer.Start()
 	}()
 
 	for {
@@ -261,7 +262,7 @@ func (a *Agent) Shutdown() error {
 	a.stateLock.Lock()
 	defer a.stateLock.Unlock()
 
-	a.metricsServer.shutdown()
+	a.metricsServer.Shutdown()
 
 	if a.Self.Status == member.Shutdown {
 		return nil
diff --git a/gossip/agent_test.go b/gossip/agent_test.go
index 8c36100e9..9641cab61 100644
--- a/gossip/agent_test.go
+++ b/gossip/agent_test.go
@@ -23,6 +23,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/bbva/qed/gossip/member"
+	"github.com/bbva/qed/metrics"
 )
 
 func TestJoin(t *testing.T) {
@@ -30,7 +31,8 @@ func TestJoin(t *testing.T) {
 	conf.NodeName = "testNode"
 	conf.Role = member.Auditor
 	conf.BindAddr = "127.0.0.1:12345"
-	a, _ := NewAgent(conf, []Processor{FakeProcessor{}})
+	metricsServer := metrics.NewServer("127.0.0.2:23464")
+	a, _ := NewAgent(conf, []Processor{FakeProcessor{}}, metricsServer)
 
 	testCases := []struct {
 		agentState             member.Status
@@ -71,7 +73,8 @@ func TestLeave(t *testing.T) {
 	conf.NodeName = "testNode"
 	conf.Role = member.Auditor
 	conf.BindAddr = "127.0.0.1:12346"
-	a, _ := NewAgent(conf, []Processor{FakeProcessor{}})
+	metricsServer := metrics.NewServer("127.0.0.2:13445")
+	a, _ := NewAgent(conf, []Processor{FakeProcessor{}}, metricsServer)
 
 	testCases := []struct {
 		agentState  member.Status
@@ -119,7 +122,8 @@ func TestShutdown(t *testing.T) {
 	conf.NodeName = "testNode"
 	conf.Role = member.Auditor
 	conf.BindAddr = "127.0.0.1:12347"
-	a, _ := NewAgent(conf, []Processor{FakeProcessor{}})
+	metricsServer := metrics.NewServer("127.0.0.2:43512")
+	a, _ := NewAgent(conf, []Processor{FakeProcessor{}}, metricsServer)
 
 	testCases := []struct {
 		agentState  member.Status
diff --git a/gossip/auditor/auditor.go b/gossip/auditor/auditor.go
index 9f9af901a..6afe3a1b6 100644
--- a/gossip/auditor/auditor.go
+++ b/gossip/auditor/auditor.go
@@ -28,6 +28,7 @@ import (
 	"github.com/bbva/qed/client"
 	"github.com/bbva/qed/hashing"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/protocol"
 	"github.com/pkg/errors"
 
@@ -123,7 +124,7 @@ func NewAuditor(conf Config) (*Auditor, error) {
 	return &auditor, nil
 }
 
-func (a Auditor) RegisterMetrics(r *prometheus.Registry) {
+func (a Auditor) RegisterMetrics(srv *metrics.Server) {
 	metrics := []prometheus.Collector{
 		QedAuditorInstancesCount,
 		QedAuditorBatchesProcessSeconds,
@@ -132,7 +133,7 @@ func (a Auditor) RegisterMetrics(r *prometheus.Registry) {
 	}
 
 	for _, m := range metrics {
-		r.Register(m)
+		srv.Register(m)
 	}
 }
 
diff --git a/gossip/metrics.go b/gossip/metrics.go
deleted file mode 100644
index 4a281086a..000000000
--- a/gossip/metrics.go
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
-   Copyright 2018 Banco Bilbao Vizcaya Argentaria, S.A.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package gossip
-
-import (
-	"context"
-	"net/http"
-	"time"
-
-	"github.com/bbva/qed/api/metricshttp"
-	"github.com/bbva/qed/log"
-	"github.com/prometheus/client_golang/prometheus"
-)
-
-type metricsServer struct {
-	server   *http.Server
-	registry *prometheus.Registry
-}
-
-func newMetricsServer(addr string) *metricsServer {
-	r := prometheus.NewRegistry()
-	return &metricsServer{
-		server: &http.Server{
-			Addr:    addr,
-			Handler: metricshttp.NewMetricsHTTP(r),
-		},
-		registry: r,
-	}
-}
-
-func (m metricsServer) start() {
-	if err := m.server.ListenAndServe(); err != http.ErrServerClosed {
-		log.Errorf("Can't start metrics HTTP server: %s", err)
-	}
-}
-
-func (m metricsServer) shutdown() {
-	ctx, _ := context.WithTimeout(context.Background(), 5*time.Second)
-	m.server.Shutdown(ctx)
-}
-
-func (m metricsServer) register(metric prometheus.Collector) {
-	if err := m.registry.Register(metric); err != nil {
-		log.Infof("metric not registered:", err)
-	} else {
-		log.Infof("metric registered.")
-	}
-}
-
diff --git a/gossip/monitor/monitor.go b/gossip/monitor/monitor.go
index 68b2379da..63576ed85 100644
--- a/gossip/monitor/monitor.go
+++ b/gossip/monitor/monitor.go
@@ -28,6 +28,7 @@ import (
 	"github.com/bbva/qed/client"
 	"github.com/bbva/qed/hashing"
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/protocol"
 	"github.com/pkg/errors"
 
@@ -120,7 +121,7 @@ func NewMonitor(conf *Config) (*Monitor, error) {
 	return &monitor, nil
 }
 
-func (m Monitor) RegisterMetrics(r *prometheus.Registry) {
+func (m Monitor) RegisterMetrics(srv *metrics.Server) {
 	metrics := []prometheus.Collector{
 		QedMonitorInstancesCount,
 		QedMonitorBatchesReceivedTotal,
@@ -129,7 +130,7 @@ func (m Monitor) RegisterMetrics(r *prometheus.Registry) {
 	}
 
 	for _, m := range metrics {
-		r.Register(m)
+		srv.Register(m)
 	}
 }
 
diff --git a/gossip/processor.go b/gossip/processor.go
index 3c3c8a79f..2be11922f 100644
--- a/gossip/processor.go
+++ b/gossip/processor.go
@@ -22,25 +22,25 @@ import (
 	"net/http"
 
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/protocol"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
 type Processor interface {
 	Process(*protocol.BatchSnapshots)
-	RegisterMetrics(*prometheus.Registry)
+	RegisterMetrics(*metrics.Server)
 }
 
 type FakeProcessor struct {
 }
 
-func (d FakeProcessor) Process(b *protocol.BatchSnapshots)     {}
-func (d FakeProcessor) RegisterMetrics(r *prometheus.Registry) {}
+func (d FakeProcessor) Process(b *protocol.BatchSnapshots) {}
+func (d FakeProcessor) RegisterMetrics(m *metrics.Server)  {}
 
 type DummyProcessor struct {
 }
 
-func (d DummyProcessor) RegisterMetrics(r *prometheus.Registry) {}
+func (d DummyProcessor) RegisterMetrics(m *metrics.Server) {}
 
 func (d DummyProcessor) Process(b *protocol.BatchSnapshots) {
 	for i := 0; i < len(b.Snapshots); i++ {
diff --git a/gossip/publisher/publisher.go b/gossip/publisher/publisher.go
index 458b1b080..d273293f8 100644
--- a/gossip/publisher/publisher.go
+++ b/gossip/publisher/publisher.go
@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/bbva/qed/log"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/protocol"
 	"github.com/coocood/freecache"
 
@@ -105,7 +106,7 @@ func NewPublisher(conf Config) (*Publisher, error) {
 	return &publisher, nil
 }
 
-func (p Publisher) RegisterMetrics(r *prometheus.Registry) {
+func (p Publisher) RegisterMetrics(srv *metrics.Server) {
 	metrics := []prometheus.Collector{
 		QedPublisherInstancesCount,
 		QedPublisherBatchesReceivedTotal,
@@ -113,7 +114,7 @@ func (p Publisher) RegisterMetrics(r *prometheus.Registry) {
 	}
 
 	for _, m := range metrics {
-		r.Register(m)
+		srv.Register(m)
 	}
 }
 
diff --git a/metrics/definitions.go b/metrics/definitions.go
new file mode 100644
index 000000000..0d3b9eae2
--- /dev/null
+++ b/metrics/definitions.go
@@ -0,0 +1,198 @@
+/*
+   Copyright 2018-2019 Banco Bilbao Vizcaya Argentaria, S.A.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package metrics
+
+import (
+	"expvar"
+	"fmt"
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+
+	// Balloon has a Map of all the stats relative to Balloon
+	Balloon *expvar.Map
+
+	// Prometheus
+
+	// SERVER
+
+	QedInstancesCount = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "qed_instances_count",
+			Help: "Number of QED servers currently running",
+		},
+	)
+
+	// API
+
+	QedAPIHealthcheckRequestsTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_api_healthcheck_requests_total",
+			Help: "The total number of healthcheck api requests",
+		},
+	)
+
+	// BALLOON
+
+	QedBalloonAddDurationSeconds = prometheus.NewSummary(
+		prometheus.SummaryOpts{
+			Name: "qed_balloon_add_duration_seconds",
+			Help: "Duration of the add operation.",
+		},
+	)
+	QedBalloonMembershipDurationSeconds = prometheus.NewSummary(
+		prometheus.SummaryOpts{
+			Name: "qed_balloon_membership_duration_seconds",
+			Help: "Duration of the membership queries.",
+		},
+	)
+	QedBalloonDigestMembershipDurationSeconds = prometheus.NewSummary(
+		prometheus.SummaryOpts{
+			Name: "qed_balloon_digest_membership_duration_seconds",
+			Help: "Duration of the membership by digest queries.",
+		},
+	)
+	QedBalloonIncrementalDurationSeconds = prometheus.NewSummary(
+		prometheus.SummaryOpts{
+			Name: "qed_balloon_incremental_duration_seconds",
+			Help: "Duration of the incremental queries.",
+		},
+	)
+	QedBalloonAddTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_balloon_add_total",
+			Help: "Number of add operations",
+		},
+	)
+	QedBalloonMembershipTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_balloon_membership_total",
+			Help: "Number of membership queries.",
+		},
+	)
+	QedBalloonDigestMembershipTotal = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "qed_balloon_digest_membership_total",
+			Help: "Number of membership by digest queries.",
+		},
+	)
+	QedBalloonIncrementalTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_balloon_incremental_total",
+			Help: "Number of incremental queries.",
+		},
+	)
+
+	// HYPER TREE
+
+	QedHyperAddTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_hyper_add_total",
+			Help: "Number of the events added to the hyper tree.",
+		},
+	)
+	QedHyperMembershipTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_hyper_membership_total",
+			Help: "Number of membership queries",
+		},
+	)
+
+	// HISTORY TREE
+
+	QedHistoryAddTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_history_add_total",
+			Help: "Number of the events added to the history tree.",
+		},
+	)
+	QedHistoryMembershipTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_history_membership_total",
+			Help: "Number of membership queries",
+		},
+	)
+	QedHistoryConsistencyTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_history_consistency_total",
+			Help: "Number of consistency queries",
+		},
+	)
+
+	// SENDER
+
+	QedSenderInstancesCount = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "qed_sender_instances_count",
+			Help: "Number of sender agents running",
+		},
+	)
+	QedSenderBatchesSentTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "qed_sender_batches_sent_total",
+			Help: "Number of batches sent by the sender.",
+		},
+	)
+
+	// PROMETHEUS
+
+	metricsList = []prometheus.Collector{
+		QedInstancesCount,
+		QedAPIHealthcheckRequestsTotal,
+
+		QedBalloonAddDurationSeconds,
+		QedBalloonMembershipDurationSeconds,
+		QedBalloonDigestMembershipDurationSeconds,
+		QedBalloonIncrementalDurationSeconds,
+
+		QedBalloonAddTotal,
+		QedBalloonMembershipTotal,
+		QedBalloonDigestMembershipTotal,
+		QedBalloonIncrementalTotal,
+
+		QedSenderInstancesCount,
+		QedSenderBatchesSentTotal,
+	}
+
+	registerMetrics sync.Once
+)
+
+// Register all metrics.
+func Register(r *prometheus.Registry) {
+	// Register the metrics.
+	registerMetrics.Do(
+		func() {
+			for _, metric := range metricsList {
+				r.MustRegister(metric)
+			}
+		},
+	)
+}
+
+// Implement expVar.Var interface
+type Uint64ToVar uint64
+
+func (v Uint64ToVar) String() string {
+	return fmt.Sprintf("%d", v)
+}
+
+func init() {
+	Balloon = expvar.NewMap("Qed_balloon_stats")
+}
diff --git a/metrics/metrics.go b/metrics/metrics.go
index 0d3b9eae2..95315ca28 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -1,5 +1,5 @@
 /*
-   Copyright 2018-2019 Banco Bilbao Vizcaya Argentaria, S.A.
+   Copyright 2018 Banco Bilbao Vizcaya Argentaria, S.A.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
@@ -17,182 +17,47 @@
 package metrics
 
 import (
-	"expvar"
-	"fmt"
-	"sync"
+	"context"
+	"net/http"
+	"time"
 
+	"github.com/bbva/qed/api/metricshttp"
+	"github.com/bbva/qed/log"
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-var (
-
-	// Balloon has a Map of all the stats relative to Balloon
-	Balloon *expvar.Map
-
-	// Prometheus
-
-	// SERVER
-
-	QedInstancesCount = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Name: "qed_instances_count",
-			Help: "Number of QED servers currently running",
-		},
-	)
-
-	// API
-
-	QedAPIHealthcheckRequestsTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_api_healthcheck_requests_total",
-			Help: "The total number of healthcheck api requests",
-		},
-	)
-
-	// BALLOON
-
-	QedBalloonAddDurationSeconds = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Name: "qed_balloon_add_duration_seconds",
-			Help: "Duration of the add operation.",
-		},
-	)
-	QedBalloonMembershipDurationSeconds = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Name: "qed_balloon_membership_duration_seconds",
-			Help: "Duration of the membership queries.",
-		},
-	)
-	QedBalloonDigestMembershipDurationSeconds = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Name: "qed_balloon_digest_membership_duration_seconds",
-			Help: "Duration of the membership by digest queries.",
-		},
-	)
-	QedBalloonIncrementalDurationSeconds = prometheus.NewSummary(
-		prometheus.SummaryOpts{
-			Name: "qed_balloon_incremental_duration_seconds",
-			Help: "Duration of the incremental queries.",
-		},
-	)
-	QedBalloonAddTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_balloon_add_total",
-			Help: "Number of add operations",
-		},
-	)
-	QedBalloonMembershipTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_balloon_membership_total",
-			Help: "Number of membership queries.",
-		},
-	)
-	QedBalloonDigestMembershipTotal = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Name: "qed_balloon_digest_membership_total",
-			Help: "Number of membership by digest queries.",
-		},
-	)
-	QedBalloonIncrementalTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_balloon_incremental_total",
-			Help: "Number of incremental queries.",
-		},
-	)
-
-	// HYPER TREE
-
-	QedHyperAddTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_hyper_add_total",
-			Help: "Number of the events added to the hyper tree.",
-		},
-	)
-	QedHyperMembershipTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_hyper_membership_total",
-			Help: "Number of membership queries",
-		},
-	)
-
-	// HISTORY TREE
-
-	QedHistoryAddTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_history_add_total",
-			Help: "Number of the events added to the history tree.",
-		},
-	)
-	QedHistoryMembershipTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_history_membership_total",
-			Help: "Number of membership queries",
-		},
-	)
-	QedHistoryConsistencyTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_history_consistency_total",
-			Help: "Number of consistency queries",
-		},
-	)
-
-	// SENDER
+type Server struct {
+	server   *http.Server
+	registry *prometheus.Registry
+}
 
-	QedSenderInstancesCount = prometheus.NewGauge(
-		prometheus.GaugeOpts{
-			Name: "qed_sender_instances_count",
-			Help: "Number of sender agents running",
-		},
-	)
-	QedSenderBatchesSentTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Name: "qed_sender_batches_sent_total",
-			Help: "Number of batches sent by the sender.",
+func NewServer(addr string) *Server {
+	r := prometheus.NewRegistry()
+	return &Server{
+		server: &http.Server{
+			Addr:    addr,
+			Handler: metricshttp.NewMetricsHTTP(r),
 		},
-	)
-
-	// PROMETHEUS
-
-	metricsList = []prometheus.Collector{
-		QedInstancesCount,
-		QedAPIHealthcheckRequestsTotal,
-
-		QedBalloonAddDurationSeconds,
-		QedBalloonMembershipDurationSeconds,
-		QedBalloonDigestMembershipDurationSeconds,
-		QedBalloonIncrementalDurationSeconds,
-
-		QedBalloonAddTotal,
-		QedBalloonMembershipTotal,
-		QedBalloonDigestMembershipTotal,
-		QedBalloonIncrementalTotal,
-
-		QedSenderInstancesCount,
-		QedSenderBatchesSentTotal,
+		registry: r,
 	}
-
-	registerMetrics sync.Once
-)
-
-// Register all metrics.
-func Register(r *prometheus.Registry) {
-	// Register the metrics.
-	registerMetrics.Do(
-		func() {
-			for _, metric := range metricsList {
-				r.MustRegister(metric)
-			}
-		},
-	)
 }
 
-// Implement expVar.Var interface
-type Uint64ToVar uint64
+func (m Server) Start() {
+	if err := m.server.ListenAndServe(); err != http.ErrServerClosed {
+		log.Errorf("Can't start metrics HTTP server: %s", err)
+	}
+}
 
-func (v Uint64ToVar) String() string {
-	return fmt.Sprintf("%d", v)
+func (m Server) Shutdown() {
+	ctx, _ := context.WithTimeout(context.Background(), 5*time.Second)
+	m.server.Shutdown(ctx)
 }
 
-func init() {
-	Balloon = expvar.NewMap("Qed_balloon_stats")
+func (m Server) Register(metric prometheus.Collector) {
+	if err := m.registry.Register(metric); err != nil {
+		log.Infof("metric not registered:", err)
+	} else {
+		log.Infof("metric registered.")
+	}
 }
+
diff --git a/server/server.go b/server/server.go
index e864fb68f..a87e61331 100644
--- a/server/server.go
+++ b/server/server.go
@@ -33,7 +33,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 
 	"github.com/bbva/qed/api/apihttp"
-	"github.com/bbva/qed/api/metricshttp"
 	"github.com/bbva/qed/api/mgmthttp"
 	"github.com/bbva/qed/api/tampering"
 	"github.com/bbva/qed/gossip"
@@ -58,7 +57,7 @@ type Server struct {
 	mgmtServer         *http.Server
 	raftBalloon        *raftwal.RaftBalloon
 	tamperingServer    *http.Server
-	metricsServer      *http.Server
+	metricsServer      *metrics.Server
 	prometheusRegistry *prometheus.Registry
 	signer             sign.Signer
 	sender             *sender.Sender
@@ -123,12 +122,16 @@ func NewServer(conf *Config) (*Server, error) {
 		return nil, err
 	}
 
+	// metrics server
+	server.metricsServer = metrics.NewServer(conf.MetricsAddr)
+
 	// Create gossip agent
 	config := gossip.DefaultConfig()
 	config.BindAddr = conf.GossipAddr
 	config.Role = member.Server
 	config.NodeName = conf.NodeID
-	server.agent, err = gossip.NewAgent(config, nil)
+
+	server.agent, err = gossip.NewAgent(config, nil, server.metricsServer)
 	if err != nil {
 		return nil, err
 	}
@@ -173,13 +176,6 @@ func NewServer(conf *Config) (*Server, error) {
 		server.tamperingServer = newHTTPServer(fmt.Sprintf("localhost:1880%d", id), tamperMux)
 	}
 
-	r := prometheus.NewRegistry()
-	metrics.Register(r)
-	server.prometheusRegistry = r
-	metricsMux := metricshttp.NewMetricsHTTP(r)
-
-	server.metricsServer = newHTTPServer(conf.MetricsAddr, metricsMux)
-
 	return server, nil
 }
 
@@ -218,9 +214,7 @@ func (s *Server) Start() error {
 
 	go func() {
 		log.Debugf("	* Starting metrics HTTP server in addr: %s", s.conf.MetricsAddr)
-		if err := s.metricsServer.ListenAndServe(); err != http.ErrServerClosed {
-			log.Errorf("Can't start metrics HTTP server: %s", err)
-		}
+		s.metricsServer.Start()
 	}()
 
 	if s.tamperingServer != nil {
@@ -290,10 +284,8 @@ func (s *Server) Stop() error {
 	log.Infof("\nShutting down QED server %s", s.conf.NodeID)
 
 	log.Debugf("Metrics enabled: stopping server...")
-	if err := s.metricsServer.Shutdown(context.Background()); err != nil { // TODO include timeout instead nil
-		log.Error(err)
-		return err
-	}
+	s.metricsServer.Shutdown()
+
 	log.Debugf("Done.\n")
 
 	if s.tamperingServer != nil {
diff --git a/tests/e2e/setup.go b/tests/e2e/setup.go
index 516a0fea7..1b04c23c4 100644
--- a/tests/e2e/setup.go
+++ b/tests/e2e/setup.go
@@ -34,6 +34,7 @@ import (
 	"github.com/bbva/qed/gossip/member"
 	"github.com/bbva/qed/gossip/monitor"
 	"github.com/bbva/qed/gossip/publisher"
+	"github.com/bbva/qed/metrics"
 	"github.com/bbva/qed/server"
 	"github.com/bbva/qed/testutils/scope"
 	"github.com/pkg/errors"
@@ -123,8 +124,8 @@ func newAgent(id int, name string, role member.Type, p gossip.Processor, t *test
 	agentConf.EnableCompression = true
 	agentConf.AlertsUrls = []string{AlertsURL}
 	agentConf.Role = role
-
-	agent, err := gossip.NewAgent(agentConf, []gossip.Processor{p})
+	metricsServer := metrics.NewServer(agentConf.MetricsAddr)
+	agent, err := gossip.NewAgent(agentConf, []gossip.Processor{p}, metricsServer)
 	if err != nil {
 		t.Fatalf("Failed to start AGENT %s: %v", name, err)
 	}