Added EstimatedGasBuffer and addressed feedback

common/fee/models.go

@@ -14,6 +14,7 @@ var (
 	ErrBumpFeeExceedsLimit = errors.New("fee bump exceeds limit")
 	ErrBump                = errors.New("fee bump failed")
 	ErrConnectivity        = errors.New("transaction propagation issue: transactions are not being mined")
+	ErrFeeLimitTooLow      = errors.New("provided fee limit too low")
 )
 
 func IsBumpErr(err error) bool {

common/txmgr/broadcaster.go

@@ -20,6 +20,7 @@ import (
 	"github.com/smartcontractkit/chainlink-common/pkg/utils"
 
 	"github.com/smartcontractkit/chainlink/v2/common/client"
+	commonfee "github.com/smartcontractkit/chainlink/v2/common/fee"
 	feetypes "github.com/smartcontractkit/chainlink/v2/common/fee/types"
 	txmgrtypes "github.com/smartcontractkit/chainlink/v2/common/txmgr/types"
 	"github.com/smartcontractkit/chainlink/v2/common/types"
@@ -434,7 +435,11 @@ func (eb *Broadcaster[CHAIN_ID, HEAD, ADDR, TX_HASH, BLOCK_HASH, SEQ, FEE]) hand
 	}
 
 	attempt, _, _, retryable, err := eb.NewTxAttempt(ctx, *etx, eb.lggr)
-	if err != nil {
+	// Mark transaction as fatal if provided gas limit is set too low
+	if errors.Is(err, commonfee.ErrFeeLimitTooLow) {
+		etx.Error = null.StringFrom(commonfee.ErrFeeLimitTooLow.Error())
+		return eb.saveFatallyErroredTransaction(eb.lggr, etx), false
+	} else if err != nil {
 		return fmt.Errorf("processUnstartedTxs failed on NewAttempt: %w", err), retryable
 	}
 

core/capabilities/ccip/ocrimpls/contract_transmitter_test.go

@@ -614,6 +614,7 @@ func (g *TestGasEstimatorConfig) PriceMaxKey(addr common.Address) *assets.Wei {
 	return assets.GWei(1)
 }
 func (g *TestGasEstimatorConfig) EstimateGasLimit() bool { return false }
+func (g *TestGasEstimatorConfig) EstimatedGasBuffer() float32 { return 1.25}
 
 func (e *TestEvmConfig) GasEstimator() evmconfig.GasEstimator {
 	return &TestGasEstimatorConfig{bumpThreshold: e.BumpThreshold}

core/chains/evm/config/chain_scoped_gas_estimator.go

@@ -112,6 +112,11 @@ func (g *gasEstimatorConfig) EstimateGasLimit() bool {
 	return *g.c.EstimateGasLimit
 }
 
+func (g *gasEstimatorConfig) EstimatedGasBuffer() float32 {
+	f, _ := g.c.EstimatedGasBuffer.BigFloat().Float32()
+	return f
+}
+
 type limitJobTypeConfig struct {
 	c toml.GasLimitJobType
 }

core/chains/evm/config/config.go

@@ -137,6 +137,7 @@ type GasEstimator interface {
 	Mode() string
 	PriceMaxKey(gethcommon.Address) *assets.Wei
 	EstimateGasLimit() bool
+	EstimatedGasBuffer() float32
 }
 
 type LimitJobType interface {

core/chains/evm/config/toml/config.go

@@ -541,12 +541,13 @@ type GasEstimator struct {
 	PriceMax     *assets.Wei
 	PriceMin     *assets.Wei
 
-	LimitDefault     *uint64
-	LimitMax         *uint64
-	LimitMultiplier  *decimal.Decimal
-	LimitTransfer    *uint64
-	LimitJobType     GasLimitJobType `toml:",omitempty"`
-	EstimateGasLimit *bool
+	LimitDefault       *uint64
+	LimitMax           *uint64
+	LimitMultiplier    *decimal.Decimal
+	LimitTransfer      *uint64
+	LimitJobType       GasLimitJobType `toml:",omitempty"`
+	EstimateGasLimit   *bool
+	EstimatedGasBuffer *decimal.Decimal
 
 	BumpMin       *assets.Wei
 	BumpPercent   *uint16
@@ -637,6 +638,9 @@ func (e *GasEstimator) setFrom(f *GasEstimator) {
 	if v := f.EstimateGasLimit; v != nil {
 		e.EstimateGasLimit = v
 	}
+	if v := f.EstimatedGasBuffer; v != nil {
+		e.EstimatedGasBuffer = v
+	}
 	if v := f.PriceDefault; v != nil {
 		e.PriceDefault = v
 	}

core/chains/evm/config/toml/defaults/fallback.toml

@@ -48,6 +48,7 @@ FeeCapDefault = '100 gwei'
 TipCapDefault = '1'
 TipCapMin = '1'
 EstimateGasLimit = false
+EstimatedGasBuffer = 1.25
 
 [GasEstimator.BlockHistory]
 BatchSize = 25

core/chains/evm/gas/helpers_test.go

@@ -158,6 +158,7 @@ type MockGasEstimatorConfig struct {
 	LimitMaxF           uint64
 	ModeF               string
 	EstimateGasLimitF   bool
+	EstimatedGasBufferF float32
 }
 
 func NewMockGasConfig() *MockGasEstimatorConfig {
@@ -219,3 +220,7 @@ func (m *MockGasEstimatorConfig) Mode() string {
 func (m *MockGasEstimatorConfig) EstimateGasLimit() bool {
 	return m.EstimateGasLimitF
 }
+
+func (m *MockGasEstimatorConfig) EstimatedGasBuffer() float32 {
+	return m.EstimatedGasBufferF
+}

core/chains/evm/gas/models.go

@@ -33,7 +33,7 @@ type EvmFeeEstimator interface {
 
 	// L1Oracle returns the L1 gas price oracle only if the chain has one, e.g. OP stack L2s and Arbitrum.
 	L1Oracle() rollups.L1Oracle
-	GetFee(ctx context.Context, calldata []byte, feeLimit uint64, maxFeePrice *assets.Wei, toAddress *common.Address, opts ...feetypes.Opt) (fee EvmFee, chainSpecificFeeLimit uint64, err error)
+	GetFee(ctx context.Context, calldata []byte, feeLimit uint64, maxFeePrice *assets.Wei, toAddress *common.Address, opts ...feetypes.Opt) (fee EvmFee, estimatedFeeLimit uint64, err error)
 	BumpFee(ctx context.Context, originalFee EvmFee, feeLimit uint64, maxFeePrice *assets.Wei, attempts []EvmPriorAttempt) (bumpedFee EvmFee, chainSpecificFeeLimit uint64, err error)
 
 	// GetMaxCost returns the total value = max price x fee units + transferred value
@@ -71,6 +71,8 @@ func NewEstimator(lggr logger.Logger, ethClient feeEstimatorClient, cfg Config,
 		"tipCapMin", geCfg.TipCapMin(),
 		"priceMax", geCfg.PriceMax(),
 		"priceMin", geCfg.PriceMin(),
+		"estimateGasLimit", geCfg.EstimateGasLimit(),
+		"estimatedGasBuffer", geCfg.EstimatedGasBuffer(),
 	)
 	df := geCfg.EIP1559DynamicFees()
 
@@ -264,13 +266,10 @@ func (e *evmFeeEstimator) L1Oracle() rollups.L1Oracle {
 	return e.EvmEstimator.L1Oracle()
 }
 
-func (e *evmFeeEstimator) GetFee(ctx context.Context, calldata []byte, feeLimit uint64, maxFeePrice *assets.Wei, toAddress *common.Address, opts ...feetypes.Opt) (fee EvmFee, chainSpecificFeeLimit uint64, err error) {
-	// Create call msg for gas limit estimation, if needed
-	callMsg := ethereum.CallMsg{
-		To:   toAddress,
-		Data: calldata,
-	}
-
+// GetFee returns an initial estimated gas price and gas limit for a transaction
+// The gas limit provided by the caller can be adjusted by gas estimation or for 2D fees
+func (e *evmFeeEstimator) GetFee(ctx context.Context, calldata []byte, feeLimit uint64, maxFeePrice *assets.Wei, toAddress *common.Address, opts ...feetypes.Opt) (fee EvmFee, estimatedFeeLimit uint64, err error) {
+	var chainSpecificFeeLimit uint64
 	// get dynamic fee
 	if e.EIP1559Enabled {
 		var dynamicFee DynamicFee
@@ -281,31 +280,15 @@ func (e *evmFeeEstimator) GetFee(ctx context.Context, calldata []byte, feeLimit
 		fee.DynamicFeeCap = dynamicFee.FeeCap
 		fee.DynamicTipCap = dynamicFee.TipCap
 		chainSpecificFeeLimit = feeLimit
-		// Set call msg fields with dynamic fee fields for gas limit estimation, if needed
-		callMsg.GasFeeCap = fee.DynamicFeeCap.ToInt()
-		callMsg.GasTipCap = fee.DynamicTipCap.ToInt()
 	} else {
 		// get legacy fee
 		fee.Legacy, chainSpecificFeeLimit, err = e.EvmEstimator.GetLegacyGas(ctx, calldata, feeLimit, maxFeePrice, opts...)
 		if err != nil {
 			return
 		}
-		// Set call msg fields with legacy fee field for gas limit estimation, if needed
-		callMsg.GasPrice = fee.Legacy.ToInt()
-	}
-
-	if e.geCfg.EstimateGasLimit() {
-		callMsg.Gas = chainSpecificFeeLimit
-		estimatedGasLimit, estimateErr := e.ethClient.EstimateGas(ctx, callMsg)
-		if estimateErr != nil {
-			// Do not return error if estimating gas failed, we can still use the provided limit instead since it is an upper limit
-			e.lggr.Errorw("failed to estimate gas limit. falling back to provided gas limit.", "toAddress", toAddress, "data", calldata, "gasLimit", chainSpecificFeeLimit, "error", estimateErr)
-		} else {
-			chainSpecificFeeLimit = estimatedGasLimit
-		}
 	}
 
-	chainSpecificFeeLimit, err = commonfee.ApplyMultiplier(chainSpecificFeeLimit, e.geCfg.LimitMultiplier())
+	estimatedFeeLimit, err = e.estimateFeeLimit(ctx, fee, chainSpecificFeeLimit, calldata, toAddress)
 	return
 }
 
@@ -361,6 +344,56 @@ func (e *evmFeeEstimator) BumpFee(ctx context.Context, originalFee EvmFee, feeLi
 	return
 }
 
+func (e *evmFeeEstimator) estimateFeeLimit(ctx context.Context, fee EvmFee, feeLimit uint64, calldata []byte, toAddress *common.Address) (estimatedFeeLimit uint64, err error) {
+	// Use provided fee limit by default is EstimateGasLimit is disabled
+	if !e.geCfg.EstimateGasLimit() {
+		return commonfee.ApplyMultiplier(feeLimit, e.geCfg.LimitMultiplier())
+	}
+
+	// Create call msg for gas limit estimation
+	// Skip setting Gas to avoid capping the results of the estimation
+	callMsg := ethereum.CallMsg{
+		To:   toAddress,
+		Data: calldata,
+	}
+	if e.EIP1559Enabled {
+		callMsg.GasFeeCap = fee.DynamicFeeCap.ToInt()
+		callMsg.GasTipCap = fee.DynamicTipCap.ToInt()
+	} else {
+		// Set call msg fields with legacy fee field for gas limit estimation, if needed
+		callMsg.GasPrice = fee.Legacy.ToInt()
+	}
+	e.lggr.Debugw("estimating gas limit", "callMsg", callMsg)
+	gasUsed, estimateErr := e.ethClient.EstimateGas(ctx, callMsg)
+	if estimateErr != nil {
+		// Do not return error if estimate gas failed, we can still use the provided limit instead since it is an upper limit
+		e.lggr.Errorw("failed to estimate gas limit. falling back to provided gas limit.", "callMsg", callMsg, "providedGasLimit", feeLimit, "error", estimateErr)
+		estimatedFeeLimit, err = commonfee.ApplyMultiplier(feeLimit, e.geCfg.LimitMultiplier())
+		return
+	}
+	// Return error if estimated gas without the buffer exceeds the provided gas limit
+	// Transaction is destined to run out of gas and fail
+	if gasUsed > feeLimit {
+		e.lggr.Errorw("estimated gas limit exceeds provided limit", "estimatedGasLimit", gasUsed, "providedGasLimit", feeLimit)
+		return estimatedFeeLimit, commonfee.ErrFeeLimitTooLow
+	}
+	// Apply EstimatedGasBuffer multiplier to the estimated gas limit
+	estimatedFeeLimit, err = commonfee.ApplyMultiplier(gasUsed, e.geCfg.EstimatedGasBuffer())
+	if err != nil {
+		return
+	}
+
+	// Fallback to the provided gas limit if the buffer causes the estimated gas limit to exceed it
+	// The provided gas limit should be used as an upper bound to avoid unexpected behavior for products
+	if estimatedFeeLimit > feeLimit {
+		e.lggr.Debugw("estimated gas limit with buffer exceeds provided limit. falling back to the provided gas limit", "estimatedGasLimit", estimatedFeeLimit, "providedGasLimit", feeLimit)
+		estimatedFeeLimit = feeLimit
+	}
+
+	estimatedFeeLimit, err = commonfee.ApplyMultiplier(estimatedFeeLimit, e.geCfg.LimitMultiplier())
+	return
+}
+
 // Config defines an interface for configuration in the gas package
 type Config interface {
 	ChainType() chaintype.ChainType
@@ -383,6 +416,7 @@ type GasEstimatorConfig interface {
 	PriceMax() *assets.Wei
 	Mode() string
 	EstimateGasLimit() bool
+	EstimatedGasBuffer() float32
 }
 
 type BlockHistoryConfig interface {