Replace XXXGauges with XXXCounters (yorkie-team#266)

We need to check the load on the server for some period. Gauges are used
to track a single value. So, change XXXGauges to XXXCounters.

docker/docker-compose-full.yml

@@ -11,7 +11,7 @@ services:
     volumes:
     - ./prometheus.yml:/etc/prometheus/prometheus.yml:ro
   grafana:
-    image: grafana/grafana:5.1.0
+    image: grafana/grafana:latest
     container_name: grafana
     ports:
       - 3000:3000

yorkie/packs/packs.go

@@ -235,7 +235,7 @@ func pullPack(
 		return nil, err
 	}
 
-	be.Metrics.SetPushPullSnapshotBytes(len(snapshot))
+	be.Metrics.AddPushPullSnapshotBytes(len(snapshot))
 
 	return change.NewPack(docKey, pulledCP, nil, snapshot), err
 }

yorkie/profiling/metrics.go

@@ -23,22 +23,21 @@ type Metrics interface {
 	// ObservePushPullResponseSeconds adds response time metrics for PushPull API.
 	ObservePushPullResponseSeconds(seconds float64)
 
-	// SetPushPullReceivedChanges sets the number of changes metric
-	// included in the request pack of the PushPull API.
-	SetPushPullReceivedChanges(count int)
+	// AddPushPullReceivedChanges sets the number of changes
+	// included in the request pack of PushPull.
+	AddPushPullReceivedChanges(count int)
 
-	// SetPushPullSentChanges sets the number of changes metric
-	// included in the response pack of the PushPull API.
-	SetPushPullSentChanges(count int)
+	// AddPushPullSentChanges adds the number of changes
+	// included in the response pack of PushPull.
+	AddPushPullSentChanges(count int)
 
-	// ObservePushPullSnapshotDurationSeconds adds the time
-	// spent metric when taking snapshots.
+	// ObservePushPullSnapshotDurationSeconds adds an observation
+	// for creating snapshot for the response pack.
 	ObservePushPullSnapshotDurationSeconds(seconds float64)
 
-	// SetPushPullSnapshotBytes sets the snapshot byte size.
-	SetPushPullSnapshotBytes(bytes int)
+	// AddPushPullSnapshotBytes adds the snapshot byte size of response pack.
+	AddPushPullSnapshotBytes(bytes int)
 
-	// RegisterGRPCServer registers the given gRPC server to collect its
-	// metrics.
+	// RegisterGRPCServer registers the given gRPC server.
 	RegisterGRPCServer(server *grpc.Server)
 }

yorkie/profiling/prometheus/metrics.go

@@ -38,10 +38,10 @@ type Metrics struct {
 	agentVersion *prometheus.GaugeVec
 
 	pushPullResponseSeconds         prometheus.Histogram
-	pushPullReceivedChanges         prometheus.Gauge
-	pushPullSentChanges             prometheus.Gauge
+	pushPullReceivedChangesTotal    prometheus.Counter
+	pushPullSentChangesTotal        prometheus.Counter
 	pushPullSnapshotDurationSeconds prometheus.Histogram
-	pushPullSnapshotBytes           prometheus.Gauge
+	pushPullSnapshotBytesTotal      prometheus.Counter
 }
 
 // NewMetrics creates a new instance of Metrics.
@@ -70,33 +70,33 @@ func NewMetrics() (*Metrics, error) {
 		}, []string{"agent_version"}),
 		pushPullResponseSeconds: promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
 			Namespace: namespace,
-			Subsystem: "rpcserver",
-			Name:      "pushpull_response_seconds",
-			Help:      "Response time of PushPull API.",
+			Subsystem: "pushpull",
+			Name:      "response_seconds",
+			Help:      "The response time of PushPull.",
 		}),
-		pushPullReceivedChanges: promauto.With(reg).NewGauge(prometheus.GaugeOpts{
+		pushPullReceivedChangesTotal: promauto.With(reg).NewCounter(prometheus.CounterOpts{
 			Namespace: namespace,
-			Subsystem: "rpcserver",
-			Name:      "pushpull_received_changes",
-			Help:      "The number of changes included in a request pack in PushPull API.",
+			Subsystem: "pushpull",
+			Name:      "received_changes_total",
+			Help:      "The total count of changes included in request packs in PushPull.",
 		}),
-		pushPullSentChanges: promauto.With(reg).NewGauge(prometheus.GaugeOpts{
+		pushPullSentChangesTotal: promauto.With(reg).NewCounter(prometheus.CounterOpts{
 			Namespace: namespace,
-			Subsystem: "rpcserver",
-			Name:      "pushpull_sent_changes",
-			Help:      "The number of changes included in a response pack in PushPull API.",
+			Subsystem: "pushpull",
+			Name:      "sent_changes_total",
+			Help:      "The total count of changes included in response packs in PushPull.",
 		}),
 		pushPullSnapshotDurationSeconds: promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
 			Namespace: namespace,
-			Subsystem: "db",
-			Name:      "pushpull_snapshot_duration_seconds",
-			Help:      "The creation time of snapshot in PushPull API.",
+			Subsystem: "pushpull",
+			Name:      "snapshot_duration_seconds",
+			Help:      "The creation time of snapshot for response packs in PushPull.",
 		}),
-		pushPullSnapshotBytes: promauto.With(reg).NewGauge(prometheus.GaugeOpts{
+		pushPullSnapshotBytesTotal: promauto.With(reg).NewCounter(prometheus.CounterOpts{
 			Namespace: namespace,
-			Subsystem: "db",
-			Name:      "pushpull_snapshot_bytes",
-			Help:      "The number of bytes of Snapshot.",
+			Subsystem: "pushpull",
+			Name:      "snapshot_bytes_total",
+			Help:      "The total bytes of snapshots for response packs in PushPull.",
 		}),
 	}
 
@@ -107,40 +107,41 @@ func NewMetrics() (*Metrics, error) {
 	return metrics, nil
 }
 
-// ObservePushPullResponseSeconds adds response time metrics for PushPull API.
+// ObservePushPullResponseSeconds adds an observation for response time of
+// PushPull.
 func (m *Metrics) ObservePushPullResponseSeconds(seconds float64) {
 	m.pushPullResponseSeconds.Observe(seconds)
 }
 
-// SetPushPullReceivedChanges sets the number of changes metric
-// included in the request pack of the PushPull API.
-func (m *Metrics) SetPushPullReceivedChanges(count int) {
-	m.pushPullReceivedChanges.Set(float64(count))
+// AddPushPullReceivedChanges sets the number of changes
+// included in the request pack of PushPull.
+func (m *Metrics) AddPushPullReceivedChanges(count int) {
+	m.pushPullReceivedChangesTotal.Add(float64(count))
 }
 
-// SetPushPullSentChanges sets the number of changes metric
-// included in the response pack of the PushPull API.
-func (m *Metrics) SetPushPullSentChanges(count int) {
-	m.pushPullSentChanges.Set(float64(count))
+// AddPushPullSentChanges adds the number of changes
+// included in the response pack of PushPull.
+func (m *Metrics) AddPushPullSentChanges(count int) {
+	m.pushPullSentChangesTotal.Add(float64(count))
 }
 
-// ObservePushPullSnapshotDurationSeconds adds the time
-// spent metric when taking snapshots.
+// ObservePushPullSnapshotDurationSeconds adds an observation
+// for creating snapshot for the response pack.
 func (m *Metrics) ObservePushPullSnapshotDurationSeconds(seconds float64) {
 	m.pushPullSnapshotDurationSeconds.Observe(seconds)
 }
 
-// SetPushPullSnapshotBytes sets the snapshot byte size.
-func (m *Metrics) SetPushPullSnapshotBytes(bytes int) {
-	m.pushPullSnapshotBytes.Set(float64(bytes))
-}
-
-// Registry returns the registry of this metrics.
-func (m *Metrics) Registry() *prometheus.Registry {
-	return m.registry
+// AddPushPullSnapshotBytes adds the snapshot byte size of response pack.
+func (m *Metrics) AddPushPullSnapshotBytes(bytes int) {
+	m.pushPullSnapshotBytesTotal.Add(float64(bytes))
 }
 
 // RegisterGRPCServer registers the given gRPC server.
 func (m *Metrics) RegisterGRPCServer(server *grpc.Server) {
 	m.serverMetrics.InitializeMetrics(server)
 }
+
+// Registry returns the registry of this metrics.
+func (m *Metrics) Registry() *prometheus.Registry {
+	return m.registry
+}

yorkie/rpc/yorkie_server.go

@@ -249,7 +249,7 @@ func (s *yorkieServer) PushPull(
 	}
 
 	if pack.HasChanges() {
-		s.backend.Metrics.SetPushPullReceivedChanges(len(pack.Changes))
+		s.backend.Metrics.AddPushPullReceivedChanges(len(pack.Changes))
 
 		locker, err := s.backend.Coordinator.NewLocker(
 			ctx,
@@ -294,7 +294,7 @@ func (s *yorkieServer) PushPull(
 		return nil, err
 	}
 
-	s.backend.Metrics.SetPushPullSentChanges(len(pbChangePack.Changes))
+	s.backend.Metrics.AddPushPullSentChanges(len(pbChangePack.Changes))
 	s.backend.Metrics.ObservePushPullResponseSeconds(gotime.Since(start).Seconds())
 
 	return &api.PushPullResponse{