op-service/txmgr: Add threshold to gas price increase limiter

op-service/txmgr/cli.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"math/big"
 	"time"
 
@@ -13,6 +14,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/urfave/cli/v2"
 )
 
@@ -27,6 +29,7 @@ const (
 	NumConfirmationsFlagName          = "num-confirmations"
 	SafeAbortNonceTooLowCountFlagName = "safe-abort-nonce-too-low-count"
 	FeeLimitMultiplierFlagName        = "fee-limit-multiplier"
+	FeeLimitThresholdFlagName         = "txmgr.fee-limit-threshold"
 	ResubmissionTimeoutFlagName       = "resubmission-timeout"
 	NetworkTimeoutFlagName            = "network-timeout"
 	TxSendTimeoutFlagName             = "txmgr.send-timeout"
@@ -53,6 +56,7 @@ type DefaultFlagValues struct {
 	NumConfirmations          uint64
 	SafeAbortNonceTooLowCount uint64
 	FeeLimitMultiplier        uint64
+	FeeLimitThresholdGwei     float64
 	ResubmissionTimeout       time.Duration
 	NetworkTimeout            time.Duration
 	TxSendTimeout             time.Duration
@@ -65,6 +69,7 @@ var (
 		NumConfirmations:          uint64(10),
 		SafeAbortNonceTooLowCount: uint64(3),
 		FeeLimitMultiplier:        uint64(5),
+		FeeLimitThresholdGwei:     100.0,
 		ResubmissionTimeout:       48 * time.Second,
 		NetworkTimeout:            10 * time.Second,
 		TxSendTimeout:             0 * time.Second,
@@ -75,6 +80,7 @@ var (
 		NumConfirmations:          uint64(3),
 		SafeAbortNonceTooLowCount: uint64(3),
 		FeeLimitMultiplier:        uint64(5),
+		FeeLimitThresholdGwei:     100.0,
 		ResubmissionTimeout:       24 * time.Second,
 		NetworkTimeout:            10 * time.Second,
 		TxSendTimeout:             2 * time.Minute,
@@ -125,6 +131,12 @@ func CLIFlagsWithDefaults(envPrefix string, defaults DefaultFlagValues) []cli.Fl
 			Value:   defaults.FeeLimitMultiplier,
 			EnvVars: prefixEnvVars("TXMGR_FEE_LIMIT_MULTIPLIER"),
 		},
+		&cli.Float64Flag{
+			Name:    FeeLimitThresholdFlagName,
+			Usage:   "The minimum threshold (in GWei) at which fee bumping starts to be capped. Allows arbitrary fee bumps below this threshold.",
+			Value:   defaults.FeeLimitThresholdGwei,
+			EnvVars: prefixEnvVars("TXMGR_FEE_LIMIT_THRESHOLD"),
+		},
 		&cli.DurationFlag{
 			Name:    ResubmissionTimeoutFlagName,
 			Usage:   "Duration we will wait before resubmitting a transaction to L1",
@@ -169,6 +181,7 @@ type CLIConfig struct {
 	NumConfirmations          uint64
 	SafeAbortNonceTooLowCount uint64
 	FeeLimitMultiplier        uint64
+	FeeLimitThresholdGwei     float64
 	ResubmissionTimeout       time.Duration
 	ReceiptQueryInterval      time.Duration
 	NetworkTimeout            time.Duration
@@ -182,6 +195,7 @@ func NewCLIConfig(l1RPCURL string, defaults DefaultFlagValues) CLIConfig {
 		NumConfirmations:          defaults.NumConfirmations,
 		SafeAbortNonceTooLowCount: defaults.SafeAbortNonceTooLowCount,
 		FeeLimitMultiplier:        defaults.FeeLimitMultiplier,
+		FeeLimitThresholdGwei:     defaults.FeeLimitThresholdGwei,
 		ResubmissionTimeout:       defaults.ResubmissionTimeout,
 		NetworkTimeout:            defaults.NetworkTimeout,
 		TxSendTimeout:             defaults.TxSendTimeout,
@@ -234,6 +248,7 @@ func ReadCLIConfig(ctx *cli.Context) CLIConfig {
 		NumConfirmations:          ctx.Uint64(NumConfirmationsFlagName),
 		SafeAbortNonceTooLowCount: ctx.Uint64(SafeAbortNonceTooLowCountFlagName),
 		FeeLimitMultiplier:        ctx.Uint64(FeeLimitMultiplierFlagName),
+		FeeLimitThresholdGwei:     ctx.Float64(FeeLimitThresholdFlagName),
 		ResubmissionTimeout:       ctx.Duration(ResubmissionTimeoutFlagName),
 		ReceiptQueryInterval:      ctx.Duration(ReceiptQueryIntervalFlagName),
 		NetworkTimeout:            ctx.Duration(NetworkTimeoutFlagName),
@@ -274,10 +289,21 @@ func NewConfig(cfg CLIConfig, l log.Logger) (Config, error) {
 		return Config{}, fmt.Errorf("could not init signer: %w", err)
 	}
 
+	if thr := cfg.FeeLimitThresholdGwei; math.IsNaN(thr) || math.IsInf(thr, 0) {
+		return Config{}, fmt.Errorf("invalid fee limit threshold: %v", thr)
+	}
+
+	// convert float GWei value into integer Wei value
+	feeLimitThreshold, _ := new(big.Float).Mul(
+		big.NewFloat(cfg.FeeLimitThresholdGwei),
+		big.NewFloat(params.GWei)).
+		Int(nil)
+
 	return Config{
 		Backend:                   l1,
 		ResubmissionTimeout:       cfg.ResubmissionTimeout,
 		FeeLimitMultiplier:        cfg.FeeLimitMultiplier,
+		FeeLimitThreshold:         feeLimitThreshold,
 		ChainID:                   chainID,
 		TxSendTimeout:             cfg.TxSendTimeout,
 		TxNotInMempoolTimeout:     cfg.TxNotInMempoolTimeout,
@@ -302,6 +328,11 @@ type Config struct {
 	// The multiplier applied to fee suggestions to put a hard limit on fee increases.
 	FeeLimitMultiplier uint64
 
+	// Minimum threshold (in Wei) at which the FeeLimitMultiplier takes effect.
+	// On low-fee networks, like test networks, this allows for arbitrary fee bumps
+	// below this threshold.
+	FeeLimitThreshold *big.Int
+
 	// ChainID is the chain ID of the L1 chain.
 	ChainID *big.Int
 

op-service/txmgr/txmgr.go

@@ -513,15 +513,10 @@ func (m *SimpleTxManager) increaseGasPrice(ctx context.Context, tx *types.Transa
 	}
 	bumpedTip, bumpedFee := updateFees(tx.GasTipCap(), tx.GasFeeCap(), tip, basefee, m.l)
 
-	// Make sure increase is at most [FeeLimitMultiplier] the suggested values
-	maxTip := new(big.Int).Mul(tip, big.NewInt(int64(m.cfg.FeeLimitMultiplier)))
-	if bumpedTip.Cmp(maxTip) > 0 {
-		return nil, fmt.Errorf("bumped tip cap %v is over %dx multiple of the suggested value", bumpedTip, m.cfg.FeeLimitMultiplier)
-	}
-	maxFee := calcGasFeeCap(new(big.Int).Mul(basefee, big.NewInt(int64(m.cfg.FeeLimitMultiplier))), maxTip)
-	if bumpedFee.Cmp(maxFee) > 0 {
-		return nil, fmt.Errorf("bumped fee cap %v is over %dx multiple of the suggested value", bumpedFee, m.cfg.FeeLimitMultiplier)
+	if err := m.checkLimits(tip, basefee, bumpedTip, bumpedFee); err != nil {
+		return nil, err
 	}
+
 	rawTx := &types.DynamicFeeTx{
 		ChainID:    tx.ChainId(),
 		Nonce:      tx.Nonce(),
@@ -589,6 +584,25 @@ func (m *SimpleTxManager) suggestGasPriceCaps(ctx context.Context) (*big.Int, *b
 	return tip, head.BaseFee, nil
 }
 
+func (m *SimpleTxManager) checkLimits(tip, basefee, bumpedTip, bumpedFee *big.Int) error {
+	// If below threshold, don't apply multiplier limit
+	if thr := m.cfg.FeeLimitThreshold; thr != nil && thr.Cmp(bumpedFee) == 1 {
+		return nil
+	}
+
+	// Make sure increase is at most [FeeLimitMultiplier] the suggested values
+	feeLimitMult := big.NewInt(int64(m.cfg.FeeLimitMultiplier))
+	maxTip := new(big.Int).Mul(tip, feeLimitMult)
+	if bumpedTip.Cmp(maxTip) > 0 {
+		return fmt.Errorf("bumped tip cap %v is over %dx multiple of the suggested value", bumpedTip, m.cfg.FeeLimitMultiplier)
+	}
+	maxFee := calcGasFeeCap(new(big.Int).Mul(basefee, feeLimitMult), maxTip)
+	if bumpedFee.Cmp(maxFee) > 0 {
+		return fmt.Errorf("bumped fee cap %v is over %dx multiple of the suggested value", bumpedFee, m.cfg.FeeLimitMultiplier)
+	}
+	return nil
+}
+
 // calcThresholdValue returns x * priceBumpPercent / 100
 func calcThresholdValue(x *big.Int) *big.Int {
 	threshold := new(big.Int).Mul(priceBumpPercent, x)

op-service/txmgr/txmgr_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 )
 
 type sendTransactionFunc func(ctx context.Context, tx *types.Transaction) error
@@ -246,7 +247,6 @@ func (*mockBackend) ChainID(ctx context.Context) (*big.Int, error) {
 // receipt containing the txHash and the gasFeeCap used in the GasUsed to make
 // the value accessible from our test framework.
 func (b *mockBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
-
 	b.mu.RLock()
 	defer b.mu.RUnlock()
 
@@ -714,8 +714,8 @@ func (b *failingBackend) BlockNumber(ctx context.Context) (uint64, error) {
 // TransactionReceipt for the failingBackend returns errRpcFailure on the first
 // invocation, and a receipt containing the passed TxHash on the second.
 func (b *failingBackend) TransactionReceipt(
-	ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
-
+	ctx context.Context, txHash common.Hash,
+) (*types.Receipt, error) {
 	if !b.returnSuccessReceipt {
 		b.returnSuccessReceipt = true
 		return nil, errRpcFailure
@@ -894,9 +894,32 @@ func TestIncreaseGasPrice(t *testing.T) {
 	}
 }
 
-// TestIncreaseGasPriceNotExponential asserts that if the L1 basefee & tip remain the
-// same, repeated calls to IncreaseGasPrice do not continually increase the gas price.
-func TestIncreaseGasPriceNotExponential(t *testing.T) {
+// TestIncreaseGasPriceLimits asserts that if the L1 basefee & tip remain the
+// same, repeated calls to IncreaseGasPrice eventually hit a limit.
+func TestIncreaseGasPriceLimits(t *testing.T) {
+	t.Run("no-threshold", func(t *testing.T) {
+		testIncreaseGasPriceLimit(t, gasPriceLimitTest{
+			expTipCap: 36,
+			expFeeCap: 493, // just below 5*100
+		})
+	})
+	t.Run("with-threshold", func(t *testing.T) {
+		testIncreaseGasPriceLimit(t, gasPriceLimitTest{
+			thr:       big.NewInt(params.GWei),
+			expTipCap: 61_265_017,
+			expFeeCap: 957_582_949, // just below 1 gwei
+		})
+	})
+}
+
+type gasPriceLimitTest struct {
+	thr                  *big.Int
+	expTipCap, expFeeCap int64
+}
+
+// testIncreaseGasPriceLimit runs a gas bumping test that increases the gas price until it hits an error.
+// It starts with a tx that has a tip cap of 10 wei and fee cap of 100 wei.
+func testIncreaseGasPriceLimit(t *testing.T, lt gasPriceLimitTest) {
 	t.Parallel()
 
 	borkedTip := int64(10)
@@ -913,6 +936,7 @@ func TestIncreaseGasPriceNotExponential(t *testing.T) {
 			NumConfirmations:          1,
 			SafeAbortNonceTooLowCount: 3,
 			FeeLimitMultiplier:        5,
+			FeeLimitThreshold:         lt.thr,
 			Signer: func(ctx context.Context, from common.Address, tx *types.Transaction) (*types.Transaction, error) {
 				return tx, nil
 			},
@@ -937,10 +961,11 @@ func TestIncreaseGasPriceNotExponential(t *testing.T) {
 		}
 		tx = newTx
 	}
+
 	lastTip, lastFee := tx.GasTipCap(), tx.GasFeeCap()
-	require.Equal(t, lastTip.Int64(), int64(36))
-	require.Equal(t, lastFee.Int64(), int64(493))
-	// Confirm that fees stop rising
+	// Confirm that fees only rose until expected threshold
+	require.Equal(t, lt.expTipCap, lastTip.Int64())
+	require.Equal(t, lt.expFeeCap, lastFee.Int64())
 	_, err := mgr.increaseGasPrice(ctx, tx)
 	require.Error(t, err)
 }