feat: add MIN_L1_TX_SIZE configuration

.changeset/gentle-brooms-lick.md

+---
+'@eth-optimism/batch-submitter-service': patch
+---
+
+Adds MIN_L1_TX_SIZE configuration

go/batch-submitter/batch_submitter.go

@@ -27,6 +27,10 @@ func Main(gitVersion string) func(ctx *cli.Context) error {
 			return err
 		}
 
+		log.Info("Config parsed",
+			"min_tx_size", cfg.MinL1TxSize,
+			"max_tx_size", cfg.MaxL1TxSize)
+
 		// The call to defer is done here so that any errors logged from
 		// this point on are posted to Sentry before exiting.
 		if cfg.SentryEnable {
@@ -121,6 +125,7 @@ func Main(gitVersion string) func(ctx *cli.Context) error {
 				L1Client:    l1Client,
 				L2Client:    l2Client,
 				BlockOffset: cfg.BlockOffset,
+				MinTxSize:   cfg.MinL1TxSize,
 				MaxTxSize:   cfg.MaxL1TxSize,
 				CTCAddr:     ctcAddress,
 				ChainID:     chainID,

go/batch-submitter/config.go

@@ -197,6 +197,7 @@ func NewConfig(ctx *cli.Context) (Config, error) {
 		L2EthRpc:                  ctx.GlobalString(flags.L2EthRpcFlag.Name),
 		CTCAddress:                ctx.GlobalString(flags.CTCAddressFlag.Name),
 		SCCAddress:                ctx.GlobalString(flags.SCCAddressFlag.Name),
+		MinL1TxSize:               ctx.GlobalUint64(flags.MinL1TxSizeFlag.Name),
 		MaxL1TxSize:               ctx.GlobalUint64(flags.MaxL1TxSizeFlag.Name),
 		MaxBatchSubmissionTime:    ctx.GlobalDuration(flags.MaxBatchSubmissionTimeFlag.Name),
 		PollInterval:              ctx.GlobalDuration(flags.PollIntervalFlag.Name),

go/batch-submitter/drivers/sequencer/driver.go

@@ -32,6 +32,7 @@ type Config struct {
 	L1Client    *ethclient.Client
 	L2Client    *l2ethclient.Client
 	BlockOffset uint64
+	MinTxSize   uint64
 	MaxTxSize   uint64
 	CTCAddr     common.Address
 	ChainID     *big.Int
@@ -150,7 +151,8 @@ func (d *Driver) GetBatchBlockRange(
 
 // CraftBatchTx transforms the L2 blocks between start and end into a batch
 // transaction using the given nonce. A dummy gas price is used in the resulting
-// transaction to use for size estimation.
+// transaction to use for size estimation. A nil transaction is returned if the
+// transaction does not meet the minimum size requirements.
 //
 // NOTE: This method SHOULD NOT publish the resulting transaction.
 func (d *Driver) CraftBatchTx(
@@ -211,13 +213,18 @@ func (d *Driver) CraftBatchTx(
 		batchCallData := append(appendSequencerBatchID, batchArguments...)
 
 		// Continue pruning until calldata size is less than configured max.
-		if uint64(len(batchCallData)) > d.cfg.MaxTxSize {
+		calldataSize := uint64(len(batchCallData))
+		if calldataSize > d.cfg.MaxTxSize {
 			oldLen := len(batchElements)
 			newBatchElementsLen := (oldLen * 9) / 10
 			batchElements = batchElements[:newBatchElementsLen]
 			log.Info(name+" pruned batch", "old_num_txs", oldLen, "new_num_txs", newBatchElementsLen)
 			pruneCount++
 			continue
+		} else if calldataSize < d.cfg.MinTxSize {
+			log.Info(name+" batch tx size below minimum",
+				"size", calldataSize, "min_tx_size", d.cfg.MinTxSize)
+			return nil, nil
 		}
 
 		d.metrics.NumElementsPerBatch().Observe(float64(len(batchElements)))

go/batch-submitter/flags/flags.go

@@ -52,6 +52,13 @@ var (
 		Required: true,
 		EnvVar:   "SCC_ADDRESS",
 	}
+	MinL1TxSizeFlag = cli.Uint64Flag{
+		Name: "min-l1-tx-size",
+		Usage: "Minimum size in bytes of any L1 transaction that gets " +
+			"generated by the batch submitter",
+		Required: true,
+		EnvVar:   prefixEnvVar("MIN_L1_TX_SIZE"),
+	}
 	MaxL1TxSizeFlag = cli.Uint64Flag{
 		Name: "max-l1-tx-size",
 		Usage: "Maximum size in bytes of any L1 transaction that gets " +
@@ -231,6 +238,7 @@ var requiredFlags = []cli.Flag{
 	L2EthRpcFlag,
 	CTCAddressFlag,
 	SCCAddressFlag,
+	MinL1TxSizeFlag,
 	MaxL1TxSizeFlag,
 	MaxBatchSubmissionTimeFlag,
 	PollIntervalFlag,

go/bss-core/service.go

@@ -46,7 +46,9 @@ type Driver interface {
 
 	// CraftBatchTx transforms the L2 blocks between start and end into a batch
 	// transaction using the given nonce. A dummy gas price is used in the
-	// resulting transaction to use for size estimation.
+	// resulting transaction to use for size estimation. The driver may return a
+	// nil value for transaction if there is no action that needs to be
+	// performed.
 	//
 	// NOTE: This method SHOULD NOT publish the resulting transaction.
 	CraftBatchTx(
@@ -184,6 +186,8 @@ func (s *Service) eventLoop() {
 				log.Error(name+" unable to craft batch tx",
 					"err", err)
 				continue
+			} else if tx == nil {
+				continue
 			}
 			batchTxBuildTime := time.Since(batchTxBuildStart) / time.Millisecond
 			s.metrics.BatchTxBuildTimeMs().Set(float64(batchTxBuildTime))

ops/envs/batch-submitter.env

@@ -4,6 +4,7 @@ ETH_NETWORK_NAME=clique
 LOG_LEVEL=debug
 BATCH_SUBMITTER_LOG_LEVEL=debug
 BATCH_SUBMITTER_LOG_TERMINAL=true
+BATCH_SUBMITTER_MIN_L1_TX_SIZE=32
 BATCH_SUBMITTER_MAX_L1_TX_SIZE=90000
 BATCH_SUBMITTER_MAX_BATCH_SUBMISSION_TIME=0
 BATCH_SUBMITTER_POLL_INTERVAL=500ms