Use Counter type for channel_input_bytes

op-node/metrics/metrics.go

@@ -132,7 +132,7 @@ type Metrics struct {
 	GossipEventsTotal *prometheus.CounterVec
 	BandwidthTotal    *prometheus.GaugeVec
 
-	ChannelInputBytes prometheus.Gauge
+	ChannelInputBytes prometheus.Counter
 
 	registry *prometheus.Registry
 	factory  metrics.Factory
@@ -334,7 +334,7 @@ func NewMetrics(procName string) *Metrics {
 			"direction",
 		}),
 
-		ChannelInputBytes: factory.NewGauge(prometheus.GaugeOpts{
+		ChannelInputBytes: factory.NewCounter(prometheus.CounterOpts{
 			Namespace: ns,
 			Name:      "channel_input_bytes",
 			Help:      "Number of compressed bytes added to the channel",
@@ -645,7 +645,7 @@ func (m *Metrics) PayloadsQuarantineSize(n int) {
 }
 
 func (m *Metrics) RecordChannelInputBytes(inputCompressedBytes int) {
-	m.ChannelInputBytes.Set(float64(inputCompressedBytes))
+	m.ChannelInputBytes.Add(float64(inputCompressedBytes))
 }
 
 type noopMetricer struct{}

op-node/rollup/derive/channel_in_reader.go

@@ -23,8 +23,6 @@ type ChannelInReader struct {
 	prev *ChannelBank
 
 	metrics Metrics
-	// total amount of compressed bytes added to the channel
-	comprInputBytes int
 }
 
 var _ ResetableStage = (*ChannelInReader)(nil)
@@ -46,8 +44,7 @@ func (cr *ChannelInReader) Origin() eth.L1BlockRef {
 func (cr *ChannelInReader) WriteChannel(data []byte) error {
 	if f, err := BatchReader(bytes.NewBuffer(data), cr.Origin()); err == nil {
 		cr.nextBatchFn = f
-		cr.comprInputBytes += len(data)
-		cr.metrics.RecordChannelInputBytes(cr.comprInputBytes)
+		cr.metrics.RecordChannelInputBytes(len(data))
 		return nil
 	} else {
 		cr.log.Error("Error creating batch reader from channel data", "err", err)