Merge pull request #2173 from OffchainLabs/batchposter-l1price-metrics

Add metrics to track L1 price in batch poster [NIT-1248]
OffchainLabs · Mar 28, 2024 · d28682b · d28682b
2 parents ff9e72a + 066b9fa
commit d28682b
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Showing 9 changed files with 416 additions and 43 deletions.
diff --git a/arbnode/batch_poster.go b/arbnode/batch_poster.go
@@ -53,8 +53,18 @@ import (
 )
 
 var (
-	batchPosterWalletBalance      = metrics.NewRegisteredGaugeFloat64("arb/batchposter/wallet/balanceether", nil)
-	batchPosterGasRefunderBalance = metrics.NewRegisteredGaugeFloat64("arb/batchposter/gasrefunder/balanceether", nil)
+	batchPosterWalletBalance      = metrics.NewRegisteredGaugeFloat64("arb/batchposter/wallet/eth", nil)
+	batchPosterGasRefunderBalance = metrics.NewRegisteredGaugeFloat64("arb/batchposter/gasrefunder/eth", nil)
+	baseFeeGauge                  = metrics.NewRegisteredGauge("arb/batchposter/basefee", nil)
+	blobFeeGauge                  = metrics.NewRegisteredGauge("arb/batchposter/blobfee", nil)
+	l1GasPriceGauge               = metrics.NewRegisteredGauge("arb/batchposter/l1gasprice", nil)
+	l1GasPriceEstimateGauge       = metrics.NewRegisteredGauge("arb/batchposter/l1gasprice/estimate", nil)
+	latestBatchSurplusGauge       = metrics.NewRegisteredGauge("arb/batchposter/latestbatchsurplus", nil)
+	blockGasUsedGauge             = metrics.NewRegisteredGauge("arb/batchposter/blockgas/used", nil)
+	blockGasLimitGauge            = metrics.NewRegisteredGauge("arb/batchposter/blockgas/limit", nil)
+	blobGasUsedGauge              = metrics.NewRegisteredGauge("arb/batchposter/blobgas/used", nil)
+	blobGasLimitGauge             = metrics.NewRegisteredGauge("arb/batchposter/blobgas/limit", nil)
+	suggestedTipCapGauge          = metrics.NewRegisteredGauge("arb/batchposter/suggestedtipcap", nil)
 
 	usableBytesInBlob    = big.NewInt(int64(len(kzg4844.Blob{}) * 31 / 32))
 	blobTxBlobGasPerBlob = big.NewInt(params.BlobTxBlobGasPerBlob)
@@ -510,6 +520,49 @@ func (b *BatchPoster) checkReverts(ctx context.Context, to int64) (bool, error)
 	return false, nil
 }
 
+func (b *BatchPoster) pollForL1PriceData(ctx context.Context) {
+	headerCh, unsubscribe := b.l1Reader.Subscribe(false)
+	defer unsubscribe()
+
+	blobGasLimitGauge.Update(params.MaxBlobGasPerBlock)
+	for {
+		select {
+		case h, ok := <-headerCh:
+			if !ok {
+				log.Info("L1 headers channel checking for l1 price data has been closed")
+				return
+			}
+			baseFeeGauge.Update(h.BaseFee.Int64())
+			l1GasPrice := h.BaseFee.Uint64()
+			if h.BlobGasUsed != nil {
+				if h.ExcessBlobGas != nil {
+					blobFeePerByte := eip4844.CalcBlobFee(eip4844.CalcExcessBlobGas(*h.ExcessBlobGas, *h.BlobGasUsed))
+					blobFeePerByte.Mul(blobFeePerByte, blobTxBlobGasPerBlob)
+					blobFeePerByte.Div(blobFeePerByte, usableBytesInBlob)
+					blobFeeGauge.Update(blobFeePerByte.Int64())
+					if l1GasPrice > blobFeePerByte.Uint64()/16 {
+						l1GasPrice = blobFeePerByte.Uint64() / 16
+					}
+				}
+				blobGasUsedGauge.Update(int64(*h.BlobGasUsed))
+			}
+			blockGasUsedGauge.Update(int64(h.GasUsed))
+			blockGasLimitGauge.Update(int64(h.GasLimit))
+			suggestedTipCap, err := b.l1Reader.Client().SuggestGasTipCap(ctx)
+			if err != nil {
+				log.Error("unable to fetch suggestedTipCap from l1 client to update arb/batchposter/suggestedtipcap metric", "err", err)
+			} else {
+				suggestedTipCapGauge.Update(suggestedTipCap.Int64())
+			}
+			l1GasPriceEstimate := b.streamer.CurrentEstimateOfL1GasPrice()
+			l1GasPriceGauge.Update(int64(l1GasPrice))
+			l1GasPriceEstimateGauge.Update(int64(l1GasPriceEstimate))
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
 // pollForReverts runs a gouroutine that listens to l1 block headers, checks
 // if any transaction made by batch poster was reverted.
 func (b *BatchPoster) pollForReverts(ctx context.Context) {
@@ -1272,6 +1325,14 @@ func (b *BatchPoster) maybePostSequencerBatch(ctx context.Context) (bool, error)
 		"numBlobs", len(kzgBlobs),
 	)
 
+	surplus := arbmath.SaturatingMul(
+		arbmath.SaturatingSub(
+			l1GasPriceGauge.Snapshot().Value(),
+			l1GasPriceEstimateGauge.Snapshot().Value()),
+		int64(len(sequencerMsg)*16),
+	)
+	latestBatchSurplusGauge.Update(surplus)
+
 	recentlyHitL1Bounds := time.Since(b.lastHitL1Bounds) < config.PollInterval*3
 	postedMessages := b.building.msgCount - batchPosition.MessageCount
 	b.messagesPerBatch.Update(uint64(postedMessages))
@@ -1341,6 +1402,7 @@ func (b *BatchPoster) Start(ctxIn context.Context) {
 	b.redisLock.Start(ctxIn)
 	b.StopWaiter.Start(ctxIn, b)
 	b.LaunchThread(b.pollForReverts)
+	b.LaunchThread(b.pollForL1PriceData)
 	commonEphemeralErrorHandler := util.NewEphemeralErrorHandler(time.Minute, "", 0)
 	exceedMaxMempoolSizeEphemeralErrorHandler := util.NewEphemeralErrorHandler(5*time.Minute, dataposter.ErrExceedsMaxMempoolSize.Error(), time.Minute)
 	storageRaceEphemeralErrorHandler := util.NewEphemeralErrorHandler(5*time.Minute, storage.ErrStorageRace.Error(), time.Minute)

diff --git a/arbnode/node.go b/arbnode/node.go
@@ -756,6 +756,17 @@ func CreateNode(
 	return currentNode, nil
 }
 
+func (n *Node) CacheL1PriceDataOfMsg(pos arbutil.MessageIndex, callDataUnits uint64, l1GasCharged uint64) {
+	n.TxStreamer.CacheL1PriceDataOfMsg(pos, callDataUnits, l1GasCharged)
+}
+
+func (n *Node) BacklogL1GasCharged() uint64 {
+	return n.TxStreamer.BacklogL1GasCharged()
+}
+func (n *Node) BacklogCallDataUnits() uint64 {
+	return n.TxStreamer.BacklogCallDataUnits()
+}
+
 func (n *Node) Start(ctx context.Context) error {
 	execClient, ok := n.Execution.(*gethexec.ExecutionNode)
 	if !ok {

diff --git a/arbnode/transaction_streamer.go b/arbnode/transaction_streamer.go
@@ -68,6 +68,9 @@ type TransactionStreamer struct {
 	broadcastServer *broadcaster.Broadcaster
 	inboxReader     *InboxReader
 	delayedBridge   *DelayedBridge
+
+	cachedL1PriceDataMutex sync.RWMutex
+	cachedL1PriceData      *L1PriceData
 }
 
 type TransactionStreamerConfig struct {
@@ -112,6 +115,9 @@ func NewTransactionStreamer(
 		broadcastServer:    broadcastServer,
 		fatalErrChan:       fatalErrChan,
 		config:             config,
+		cachedL1PriceData: &L1PriceData{
+			msgToL1PriceData: []L1PriceDataOfMsg{},
+		},
 	}
 	err := streamer.cleanupInconsistentState()
 	if err != nil {
@@ -120,6 +126,120 @@ func NewTransactionStreamer(
 	return streamer, nil
 }
 
+type L1PriceDataOfMsg struct {
+	callDataUnits            uint64
+	cummulativeCallDataUnits uint64
+	l1GasCharged             uint64
+	cummulativeL1GasCharged  uint64
+}
+
+type L1PriceData struct {
+	startOfL1PriceDataCache     arbutil.MessageIndex
+	endOfL1PriceDataCache       arbutil.MessageIndex
+	msgToL1PriceData            []L1PriceDataOfMsg
+	currentEstimateOfL1GasPrice uint64
+}
+
+func (s *TransactionStreamer) CurrentEstimateOfL1GasPrice() uint64 {
+	s.cachedL1PriceDataMutex.Lock()
+	defer s.cachedL1PriceDataMutex.Unlock()
+
+	currentEstimate, err := s.exec.GetL1GasPriceEstimate()
+	if err != nil {
+		log.Error("error fetching current L2 estimate of L1 gas price hence reusing cached estimate", "err", err)
+	} else {
+		s.cachedL1PriceData.currentEstimateOfL1GasPrice = currentEstimate
+	}
+	return s.cachedL1PriceData.currentEstimateOfL1GasPrice
+}
+
+func (s *TransactionStreamer) BacklogCallDataUnits() uint64 {
+	s.cachedL1PriceDataMutex.RLock()
+	defer s.cachedL1PriceDataMutex.RUnlock()
+
+	size := len(s.cachedL1PriceData.msgToL1PriceData)
+	if size == 0 {
+		return 0
+	}
+	return (s.cachedL1PriceData.msgToL1PriceData[size-1].cummulativeCallDataUnits -
+		s.cachedL1PriceData.msgToL1PriceData[0].cummulativeCallDataUnits +
+		s.cachedL1PriceData.msgToL1PriceData[0].callDataUnits)
+}
+
+func (s *TransactionStreamer) BacklogL1GasCharged() uint64 {
+	s.cachedL1PriceDataMutex.RLock()
+	defer s.cachedL1PriceDataMutex.RUnlock()
+
+	size := len(s.cachedL1PriceData.msgToL1PriceData)
+	if size == 0 {
+		return 0
+	}
+	return (s.cachedL1PriceData.msgToL1PriceData[size-1].cummulativeL1GasCharged -
+		s.cachedL1PriceData.msgToL1PriceData[0].cummulativeL1GasCharged +
+		s.cachedL1PriceData.msgToL1PriceData[0].l1GasCharged)
+}
+
+func (s *TransactionStreamer) TrimCache(to arbutil.MessageIndex) {
+	s.cachedL1PriceDataMutex.Lock()
+	defer s.cachedL1PriceDataMutex.Unlock()
+
+	if to < s.cachedL1PriceData.startOfL1PriceDataCache {
+		log.Info("trying to trim older cache which doesnt exist anymore")
+	} else if to >= s.cachedL1PriceData.endOfL1PriceDataCache {
+		s.cachedL1PriceData.startOfL1PriceDataCache = 0
+		s.cachedL1PriceData.endOfL1PriceDataCache = 0
+		s.cachedL1PriceData.msgToL1PriceData = []L1PriceDataOfMsg{}
+	} else {
+		newStart := to - s.cachedL1PriceData.startOfL1PriceDataCache + 1
+		s.cachedL1PriceData.msgToL1PriceData = s.cachedL1PriceData.msgToL1PriceData[newStart:]
+		s.cachedL1PriceData.startOfL1PriceDataCache = to + 1
+	}
+}
+
+func (s *TransactionStreamer) CacheL1PriceDataOfMsg(seqNum arbutil.MessageIndex, callDataUnits uint64, l1GasCharged uint64) {
+	s.cachedL1PriceDataMutex.Lock()
+	defer s.cachedL1PriceDataMutex.Unlock()
+
+	resetCache := func() {
+		s.cachedL1PriceData.startOfL1PriceDataCache = seqNum
+		s.cachedL1PriceData.endOfL1PriceDataCache = seqNum
+		s.cachedL1PriceData.msgToL1PriceData = []L1PriceDataOfMsg{{
+			callDataUnits:            callDataUnits,
+			cummulativeCallDataUnits: callDataUnits,
+			l1GasCharged:             l1GasCharged,
+			cummulativeL1GasCharged:  l1GasCharged,
+		}}
+	}
+	size := len(s.cachedL1PriceData.msgToL1PriceData)
+	if size == 0 ||
+		s.cachedL1PriceData.startOfL1PriceDataCache == 0 ||
+		s.cachedL1PriceData.endOfL1PriceDataCache == 0 ||
+		arbutil.MessageIndex(size) != s.cachedL1PriceData.endOfL1PriceDataCache-s.cachedL1PriceData.startOfL1PriceDataCache+1 {
+		resetCache()
+		return
+	}
+	if seqNum != s.cachedL1PriceData.endOfL1PriceDataCache+1 {
+		if seqNum > s.cachedL1PriceData.endOfL1PriceDataCache+1 {
+			log.Info("message position higher then current end of l1 price data cache, resetting cache to this message")
+			resetCache()
+		} else if seqNum < s.cachedL1PriceData.startOfL1PriceDataCache {
+			log.Info("message position lower than start of l1 price data cache, ignoring")
+		} else {
+			log.Info("message position already seen in l1 price data cache, ignoring")
+		}
+	} else {
+		cummulativeCallDataUnits := s.cachedL1PriceData.msgToL1PriceData[size-1].cummulativeCallDataUnits
+		cummulativeL1GasCharged := s.cachedL1PriceData.msgToL1PriceData[size-1].cummulativeL1GasCharged
+		s.cachedL1PriceData.msgToL1PriceData = append(s.cachedL1PriceData.msgToL1PriceData, L1PriceDataOfMsg{
+			callDataUnits:            callDataUnits,
+			cummulativeCallDataUnits: cummulativeCallDataUnits + callDataUnits,
+			l1GasCharged:             l1GasCharged,
+			cummulativeL1GasCharged:  cummulativeL1GasCharged + l1GasCharged,
+		})
+		s.cachedL1PriceData.endOfL1PriceDataCache = seqNum
+	}
+}
+
 // Encodes a uint64 as bytes in a lexically sortable manner for database iteration.
 // Generally this is only used for database keys, which need sorted.
 // A shorter RLP encoding is usually used for database values.
@@ -577,6 +697,8 @@ func endBatch(batch ethdb.Batch) error {
 
 func (s *TransactionStreamer) AddMessagesAndEndBatch(pos arbutil.MessageIndex, messagesAreConfirmed bool, messages []arbostypes.MessageWithMetadata, batch ethdb.Batch) error {
 	if messagesAreConfirmed {
+		// Trim confirmed messages from l1pricedataCache
+		s.TrimCache(pos + arbutil.MessageIndex(len(messages)))
 		s.reorgMutex.RLock()
 		dups, _, _, err := s.countDuplicateMessages(pos, messages, nil)
 		s.reorgMutex.RUnlock()

diff --git a/arbos/l1pricing/l1pricing.go b/arbos/l1pricing/l1pricing.go
@@ -195,6 +195,23 @@ func (ps *L1PricingState) SetUnitsSinceUpdate(units uint64) error {
 	return ps.unitsSinceUpdate.Set(units)
 }
 
+func (ps *L1PricingState) GetL1PricingSurplus() (*big.Int, error) {
+	fundsDueForRefunds, err := ps.BatchPosterTable().TotalFundsDue()
+	if err != nil {
+		return nil, err
+	}
+	fundsDueForRewards, err := ps.FundsDueForRewards()
+	if err != nil {
+		return nil, err
+	}
+	haveFunds, err := ps.L1FeesAvailable()
+	if err != nil {
+		return nil, err
+	}
+	needFunds := arbmath.BigAdd(fundsDueForRefunds, fundsDueForRewards)
+	return arbmath.BigSub(haveFunds, needFunds), nil
+}
+
 func (ps *L1PricingState) LastSurplus() (*big.Int, error) {
 	return ps.lastSurplus.Get()
 }

diff --git a/execution/gethexec/executionengine.go b/execution/gethexec/executionengine.go
@@ -378,6 +378,8 @@ func (s *ExecutionEngine) sequenceTransactionsWithBlockMutex(header *arbostypes.
 		return nil, err
 	}
 
+	s.cacheL1PriceDataOfMsg(pos, receipts, block)
+
 	return block, nil
 }
 
@@ -529,6 +531,55 @@ func (s *ExecutionEngine) ResultAtPos(pos arbutil.MessageIndex) (*execution.Mess
 	return s.resultFromHeader(s.bc.GetHeaderByNumber(s.MessageIndexToBlockNumber(pos)))
 }
 
+func (s *ExecutionEngine) GetL1GasPriceEstimate() (uint64, error) {
+	bc := s.bc
+	latestHeader := bc.CurrentBlock()
+	latestState, err := bc.StateAt(latestHeader.Root)
+	if err != nil {
+		return 0, errors.New("error getting latest statedb while fetching l2 Estimate of L1 GasPrice")
+	}
+	arbState, err := arbosState.OpenSystemArbosState(latestState, nil, true)
+	if err != nil {
+		return 0, errors.New("error opening system arbos state while fetching l2 Estimate of L1 GasPrice")
+	}
+	l2EstimateL1GasPrice, err := arbState.L1PricingState().PricePerUnit()
+	if err != nil {
+		return 0, errors.New("error fetching l2 Estimate of L1 GasPrice")
+	}
+	return l2EstimateL1GasPrice.Uint64(), nil
+}
+
+func (s *ExecutionEngine) getL1PricingSurplus() (int64, error) {
+	bc := s.bc
+	latestHeader := bc.CurrentBlock()
+	latestState, err := bc.StateAt(latestHeader.Root)
+	if err != nil {
+		return 0, errors.New("error getting latest statedb while fetching current L1 pricing surplus")
+	}
+	arbState, err := arbosState.OpenSystemArbosState(latestState, nil, true)
+	if err != nil {
+		return 0, errors.New("error opening system arbos state while fetching current L1 pricing surplus")
+	}
+	surplus, err := arbState.L1PricingState().GetL1PricingSurplus()
+	if err != nil {
+		return 0, errors.New("error fetching current L1 pricing surplus")
+	}
+	return surplus.Int64(), nil
+}
+
+func (s *ExecutionEngine) cacheL1PriceDataOfMsg(num arbutil.MessageIndex, receipts types.Receipts, block *types.Block) {
+	var gasUsedForL1 uint64
+	for i := 1; i < len(receipts); i++ {
+		gasUsedForL1 += receipts[i].GasUsedForL1
+	}
+	gasChargedForL1 := gasUsedForL1 * block.BaseFee().Uint64()
+	var callDataUnits uint64
+	for _, tx := range block.Transactions() {
+		callDataUnits += tx.CalldataUnits
+	}
+	s.consensus.CacheL1PriceDataOfMsg(num, callDataUnits, gasChargedForL1)
+}
+
 // DigestMessage is used to create a block by executing msg against the latest state and storing it.
 // Also, while creating a block by executing msg against the latest state,
 // in parallel, creates a block by executing msgForPrefetch (msg+1) against the latest state

diff --git a/execution/gethexec/node.go b/execution/gethexec/node.go
@@ -275,6 +275,10 @@ func CreateExecutionNode(
 
 }
 
+func (n *ExecutionNode) GetL1GasPriceEstimate() (uint64, error) {
+	return n.ExecEngine.GetL1GasPriceEstimate()
+}
+
 func (n *ExecutionNode) Initialize(ctx context.Context) error {
 	n.ArbInterface.Initialize(n)
 	err := n.Backend.Start()