fix: don't report latency stats on late blocks

server/handlers.go

@@ -37,7 +37,16 @@ func (s *Server) handleEventEthNewHeader(
 	e := g.Endpoint(ename)
 
 	e.RegisterBlock(block, ts)
-	latency_s := g.RegisterBlockAndGetLatency(block, ts).Seconds()
+	latency := g.RegisterBlockAndGetLatency(block, ts)
+	if latency == state.Infinity {
+		l.Warn("Skipping reporting block-latency on a very late block",
+			zap.String("block", block.String()),
+			zap.String("endpoint_group", gname),
+			zap.String("endpoint_name", ename),
+		)
+		return
+	}
+	latency_s := latency.Seconds()
 
 	attrs := []attribute.KeyValue{
 		{Key: keyTargetName, Value: attribute.StringValue(ename)},

state/el_group.go

@@ -9,6 +9,10 @@ import (
 	"github.com/flashbots/node-monitor/utils"
 )
 
+const (
+	Infinity = time.Duration(9223372036854775807)
+)
+
 const (
 	maxHistoryBlocks = 1024
 )
@@ -88,19 +92,13 @@ func (g *ELGroup) RegisterBlockAndGetLatency(block *big.Int, ts time.Time) time.
 		g.mx.RLock()
 	}
 
-	// fill in the gaps (in case of missed block)
-	if prevTS, exists := g.blockTimes[blockStr]; !exists || ts.Before(prevTS) {
-		g.mx.RUnlock()
-		g.mx.Lock()
-		if prevTS, exists := g.blockTimes[blockStr]; !exists || ts.Before(prevTS) {
-			delete(g.blockTimes, g.blocks.InsertAndPop(blockStr))
-			g.blockTimes[blockStr] = ts
-		}
-		g.mx.Unlock()
-		g.mx.RLock()
+	prevTS, exists := g.blockTimes[blockStr]
+	if !exists {
+		// we don't want to report (false) statistics on obviously late blocks
+		return Infinity
 	}
 
-	return ts.Sub(g.blockTimes[blockStr])
+	return ts.Sub(prevTS)
 }
 
 func (g *ELGroup) TimeSinceHighestBlock() (block int64, timeSince time.Duration) {