fix(sync/metrics): fix blockTime metric

Author: vgonkivs

sync/metrics.go

@@ -39,8 +39,8 @@ type metrics struct {
 	requestRangeTimeHist metric.Float64Histogram
 	requestRangeStartTS  time.Time
 
-	blockTime  metric.Float64Histogram
-	prevHeader time.Time
+	blockTime    metric.Float64Histogram
+	prevHeaderTs time.Time
 }
 
 func newMetrics() (*metrics, error) {
@@ -213,12 +213,15 @@ func (m *metrics) updateGetRangeRequestInfo(ctx context.Context, amount uint64,
 	})
 }
 
-func (m *metrics) newSubjectiveHead(ctx context.Context, height uint64, timestamp time.Time) {
+func (m *metrics) newNetHead(ctx context.Context, height uint64, timestamp time.Time) {
 	m.observe(ctx, func(ctx context.Context) {
 		m.subjectiveHead.Store(height)
 
-		if !m.prevHeader.IsZero() {
-			m.blockTime.Record(ctx, timestamp.Sub(m.prevHeader).Seconds())
+		if timestamp.After(m.prevHeaderTs) {
+			if !m.prevHeaderTs.IsZero() {
+				m.blockTime.Record(ctx, timestamp.Sub(m.prevHeaderTs).Seconds())
+			}
+			m.prevHeaderTs = time.Now()
 		}
 	})
 }

sync/syncer_head.go

@@ -201,7 +201,6 @@ func (s *Syncer[H]) setLocalHead(ctx context.Context, netHead H) {
 			"hash", netHead.Hash().String(),
 			"err", err)
 	}
-	s.metrics.newSubjectiveHead(s.ctx, netHead.Height(), netHead.Time())
 
 	storeHead, err := s.store.Head(ctx)
 	if err == nil && storeHead.Height() >= netHead.Height() {
@@ -227,6 +226,7 @@ func (s *Syncer[H]) incomingNetworkHead(ctx context.Context, head H) error {
 	}
 
 	s.setLocalHead(ctx, head)
+	s.metrics.newNetHead(s.ctx, head.Height(), head.Time())
 	return nil
 }