[#701] metrics: add metric to evaluate policer performance

Add processed objects counter in policerMetrics,
add policer field to NodeMetrics

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

pkg/metrics/consts.go

@@ -20,6 +20,7 @@ const (
 	treeServiceSubsystem     = "treeservice"
 	writeCacheSubsystem      = "writecache"
 	grpcServerSubsystem      = "grpc_server"
+	policerSubsystem         = "policer"
 
 	successLabel          = "success"
 	shardIDLabel          = "shard_id"

pkg/metrics/node.go

@@ -18,6 +18,7 @@ type NodeMetrics struct {
 	metabase      *metabaseMetrics
 	pilorama      *piloramaMetrics
 	grpc          *grpcServerMetrics
+	policer       *policerMetrics
 }
 
 func NewNodeMetrics() *NodeMetrics {
@@ -39,6 +40,7 @@ func NewNodeMetrics() *NodeMetrics {
 		metabase:     newMetabaseMetrics(),
 		pilorama:     newPiloramaMetrics(),
 		grpc:         newGrpcServerMetrics(),
+		policer:      newPolicerMetrics(),
 	}
 }
 
@@ -90,3 +92,7 @@ func (m *NodeMetrics) PiloramaMetrics() PiloramaMetrics {
 func (m *NodeMetrics) GrpcServerMetrics() GrpcServerMetrics {
 	return m.grpc
 }
+
+func (m *NodeMetrics) PolicerMetrics() PolicerMetrics {
+	return m.policer
+}

pkg/metrics/policer.go

@@ -0,0 +1,29 @@
+package metrics
+
+import (
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type PolicerMetrics interface {
+	IncProcessedObjects()
+}
+
+type policerMetrics struct {
+	processedObjectsCounter prometheus.Counter
+}
+
+func newPolicerMetrics() *policerMetrics {
+	return &policerMetrics{
+		processedObjectsCounter: metrics.NewCounter(prometheus.CounterOpts{
+			Namespace: namespace,
+			Subsystem: policerSubsystem,
+			Name:      "processed_objects_total",
+			Help:      "Total number of objects processed by policer",
+		}),
+	}
+}
+
+func (m *policerMetrics) IncProcessedObjects() {
+	m.processedObjectsCounter.Inc()
+}

pkg/services/policer/metrics.go

@@ -0,0 +1,5 @@
+package policer
+
+type MetricsRegister interface {
+	IncProcessedObjects()
+}

pkg/services/policer/option.go

@@ -69,6 +69,8 @@ type cfg struct {
 	batchSize, cacheSize uint32
 
 	rebalanceFreq, evictDuration, sleepDuration time.Duration
+
+	metrics MetricsRegister
 }
 
 func defaultCfg() *cfg {

pkg/services/policer/process.go

@@ -60,6 +60,7 @@ func (p *Policer) shardPolicyWorker(ctx context.Context) {
 						}
 						p.cache.Add(addr.Address, time.Now())
 						p.objsInWork.remove(addr.Address)
+						p.metrics.IncProcessedObjects()
 					}
 				})
 				if err != nil {