Emit metrics for local memberlist size and remote memberlist size

memberlist_test.go

@@ -259,13 +259,8 @@ func TestCreate_checkBroadcastQueueMetrics(t *testing.T) {
 
 	time.Sleep(3 * time.Second)
 
-	intv := getIntervalMetrics(t, sink)
 	sampleName := "consul.usage.test.memberlist.queue.broadcasts"
-	actualSample := intv.Samples[sampleName]
-
-	if actualSample.Count == 0 {
-		t.Fatalf("%s sample not taken", sampleName)
-	}
+	verifySampleExists(t, sampleName, sink)
 }
 
 func TestCreate_keyringOnly(t *testing.T) {

net.go

@@ -1007,6 +1007,22 @@ func (m *Memberlist) sendLocalState(conn net.Conn, join bool, streamLabel string
 	}
 	m.nodeLock.RUnlock()
 
+	nodeStateCounts := make(map[string]int)
+	nodeStateCounts[StateAlive.metricsString()] = 0
+	nodeStateCounts[StateLeft.metricsString()] = 0
+	nodeStateCounts[StateDead.metricsString()] = 0
+	nodeStateCounts[StateSuspect.metricsString()] = 0
+
+	for _, n := range localNodes {
+		nodeStateCounts[n.State.metricsString()]++
+	}
+
+	for nodeState, cnt := range nodeStateCounts {
+		metrics.SetGaugeWithLabels([]string{"memberlist", "node", "instances"},
+			float32(cnt),
+			append(m.metricLabels, metrics.Label{Name: "node_state", Value: nodeState}))
+	}
+
 	// Get the delegate state
 	var userData []byte
 	if m.config.Delegate != nil {
@@ -1042,6 +1058,9 @@ func (m *Memberlist) sendLocalState(conn net.Conn, join bool, streamLabel string
 		}
 	}
 
+	moreBytes := binary.BigEndian.Uint32(bufConn.Bytes()[1:5])
+	metrics.SetGaugeWithLabels([]string{"memberlist", "size", "local"}, float32(moreBytes), m.metricLabels)
+
 	// Get the send buffer
 	return m.rawSendMsgStream(conn, bufConn.Bytes(), streamLabel)
 }
@@ -1088,6 +1107,8 @@ func (m *Memberlist) decryptRemoteState(bufConn io.Reader, streamLabel string) (
 	// Ensure we aren't asked to download too much. This is to guard against
 	// an attack vector where a huge amount of state is sent
 	moreBytes := binary.BigEndian.Uint32(cipherText.Bytes()[1:5])
+	metrics.SetGaugeWithLabels([]string{"memberlist", "size", "remote"}, float32(moreBytes), m.metricLabels)
+
 	if moreBytes > maxPushStateBytes {
 		return nil, fmt.Errorf("Remote node state is larger than limit (%d)", moreBytes)
 

state.go

@@ -15,6 +15,21 @@ import (
 
 type NodeStateType int
 
+func (t NodeStateType) metricsString() string {
+	switch t {
+	case StateAlive:
+		return "alive"
+	case StateDead:
+		return "dead"
+	case StateSuspect:
+		return "suspect"
+	case StateLeft:
+		return "left"
+	default:
+		return ""
+	}
+}
+
 const (
 	StateAlive NodeStateType = iota
 	StateSuspect

state_test.go

@@ -2239,6 +2239,8 @@ func TestMemberlist_PushPull(t *testing.T) {
 	ip1 := []byte(addr1)
 	ip2 := []byte(addr2)
 
+	sink := registerInMemorySink(t)
+
 	ch := make(chan NodeEvent, 3)
 
 	m1 := HostMemberlist(addr1.String(), t, func(c *Config) {
@@ -2270,6 +2272,13 @@ func TestMemberlist_PushPull(t *testing.T) {
 		if len(ch) < 2 {
 			failf("expected 2 messages from pushPull")
 		}
+
+		instancesMetricName := "consul.usage.test.memberlist.node.instances"
+		verifyGaugeExists(t, "consul.usage.test.memberlist.size.local", sink)
+		verifyGaugeExists(t, fmt.Sprintf("%s;node_state=%s", instancesMetricName, StateAlive.metricsString()), sink)
+		verifyGaugeExists(t, fmt.Sprintf("%s;node_state=%s", instancesMetricName, StateDead.metricsString()), sink)
+		verifyGaugeExists(t, fmt.Sprintf("%s;node_state=%s", instancesMetricName, StateLeft.metricsString()), sink)
+		verifyGaugeExists(t, fmt.Sprintf("%s;node_state=%s", instancesMetricName, StateSuspect.metricsString()), sink)
 	})
 }
 
@@ -2412,3 +2421,22 @@ func getIntervalMetrics(t *testing.T, sink *metrics.InmemSink) *metrics.Interval
 	intv := intervals[0]
 	return intv
 }
+
+func verifyGaugeExists(t *testing.T, name string, sink *metrics.InmemSink) {
+	interval := getIntervalMetrics(t, sink)
+	interval.RLock()
+	defer interval.RUnlock()
+	if _, ok := interval.Gauges[name]; !ok {
+		t.Fatalf("%s gauge not emmited", name)
+	}
+}
+
+func verifySampleExists(t *testing.T, name string, sink *metrics.InmemSink) {
+	interval := getIntervalMetrics(t, sink)
+	interval.RLock()
+	defer interval.RUnlock()
+
+	if _, ok := interval.Samples[name]; !ok {
+		t.Fatalf("%s sample not emmited", name)
+	}
+}