(feat): disable pending block creation loop via flag

docs/cli/default_config.toml

@@ -105,6 +105,7 @@ devfakeauthor = false
   base-fee-change-denominator = 0
   prefetch = false
   prefetch-gaslimit-percent = 100
+  disable-pending-block = false
 
 [jsonrpc]
   ipcdisable = false

docs/cli/example_config.toml

@@ -79,13 +79,14 @@ bp-rpc-endpoints = [ ] # Comma separated rpc endpoints of all block producers
   lifetime = "3h0m0s"           # Maximum amount of time non-executable transaction are queued
 
 [miner]
-  mine = false             # Enable mining
-  etherbase = ""           # Public address for block mining rewards
-  extradata = ""           # Block extra data set by the miner (default = client version)
-  gaslimit = 50000000      # Target gas ceiling for mined blocks (used when dynamic gas limit is disabled)
-  gasprice = "25000000000"  # Minimum gas price for mining a transaction. Regardless the value set, it will be enforced to 25000000000 for all networks
-  recommit = "2m5s"        # The time interval for miner to re-create mining work
-  commitinterrupt = true   # Interrupt the current mining work when time is exceeded and create partial blocks
+  mine = false                  # Enable mining
+  etherbase = ""                # Public address for block mining rewards
+  extradata = ""                # Block extra data set by the miner (default = client version)
+  gaslimit = 50000000           # Target gas ceiling for mined blocks (used when dynamic gas limit is disabled)
+  gasprice = "25000000000"      # Minimum gas price for mining a transaction. Regardless the value set, it will be enforced to 25000000000 for all networks
+  recommit = "2m5s"             # The time interval for miner to re-create mining work
+  commitinterrupt = true        # Interrupt the current mining work when time is exceeded and create partial blocks
+  disable-pending-block = false # Disable the pending block creation loop. When set, RPC queries for 'pending' block will return nil
   # Dynamic gas limit configuration
   enableDynamicGasLimit = false   # Enable dynamic gas limit adjustment based on base fee
   gasLimitMin = 50000000          # Minimum gas limit when dynamic gas limit is enabled

docs/cli/server.md

@@ -336,6 +336,8 @@ The ```bor server``` command runs the Bor client.
 
 - ```miner.blocktime```: The block time defined by the miner. Needs to be larger or equal to the consensus block time. If not set (default = 0), the miner will use the consensus block time. (default: 0s)
 
+- ```miner.disable-pending-block```: Disable the pending block creation loop. When set, RPC queries for 'pending' block will return nil on non block producer nodes (default: false)
+
 - ```miner.enableDynamicGasLimit```: Enable dynamic gas limit adjustment based on base fee (default: false)
 
 - ```miner.enableDynamicTargetGas```: Enable dynamic EIP-1559 target gas percentage adjustment based on base fee (post-Lisovo, mutually exclusive with enableDynamicGasLimit) (default: false)

internal/cli/server/config.go

@@ -449,6 +449,11 @@ type SealerConfig struct {
 
 	// PrefetchGasLimitPercent is the gas limit percentage for prefetching (e.g., 100 = 100%, 110 = 110%)
 	PrefetchGasLimitPercent uint64 `hcl:"prefetch-gaslimit-percent,optional" toml:"prefetch-gaslimit-percent,optional"`
+
+	// DisablePendingBlock disables the pending block creation loop which primarily builds a 'pending'
+	// block to serve rpc queries. If enabled, all 'pending' block queries will return nil. This won't
+	// apply for block producer nodes.
+	DisablePendingBlock bool `hcl:"disable-pending-block,optional" toml:"disable-pending-block,optional"`
 }
 
 type JsonRPCConfig struct {
@@ -866,7 +871,6 @@ func DefaultConfig() *Config {
 		StateScheme: "path",
 		Snapshot:    true,
 		BorLogs:     false,
-
 		TxPool: &TxPoolConfig{
 			Locals:               []string{},
 			NoLocals:             false,
@@ -906,6 +910,7 @@ func DefaultConfig() *Config {
 			PrefetchGasLimitPercent:  100,
 			TargetGasPercentage:      0, // Initialize to 0, will be set from CLI or remain 0 (meaning use default)
 			BaseFeeChangeDenominator: 0, // Initialize to 0, will be set from CLI or remain 0 (meaning use default)
+			DisablePendingBlock:      false,
 		},
 		Gpo: &GpoConfig{
 			Blocks:           20,
@@ -1277,6 +1282,7 @@ func (c *Config) buildEth(stack *node.Node, accountManager *accounts.Manager) (*
 		n.Miner.BlockTime = c.Sealer.BlockTime
 		n.Miner.EnablePrefetch = c.Sealer.EnablePrefetch
 		n.Miner.PrefetchGasLimitPercent = c.Sealer.PrefetchGasLimitPercent
+		n.Miner.DisablePendingBlock = c.Sealer.DisablePendingBlock
 
 		// Validate prefetch gas limit percentage
 		if c.Sealer.EnablePrefetch && c.Sealer.PrefetchGasLimitPercent > 150 {

internal/cli/server/flags.go

@@ -508,6 +508,13 @@ func (c *Command) Flags(config *Config) *flagset.Flagset {
 		Default: c.cliConfig.Sealer.TargetGasMaxPercentage,
 		Group:   "Sealer",
 	})
+	f.BoolFlag(&flagset.BoolFlag{
+		Name:    "miner.disable-pending-block",
+		Usage:   "Disable the pending block creation loop. When set, RPC queries for 'pending' block will return nil on non block producer nodes",
+		Value:   &c.cliConfig.Sealer.DisablePendingBlock,
+		Default: c.cliConfig.Sealer.DisablePendingBlock,
+		Group:   "Sealer",
+	})
 
 	// ethstats
 	f.StringFlag(&flagset.StringFlag{

miner/miner.go

@@ -67,6 +67,8 @@ type Config struct {
 	PendingFeeRecipient     common.Address `toml:"-"` // Address for pending block rewards.
 	EnablePrefetch          bool           // Enable transaction prefetching from pool during block building
 	PrefetchGasLimitPercent uint64         // Gas limit percentage for prefetching (e.g., 100 = 100%, 110 = 110%)
+
+	DisablePendingBlock bool // Disable the pending block creation loop on non block producer nodes
 }
 
 // DefaultConfig contains default settings for miner.
@@ -89,6 +91,8 @@ var DefaultConfig = Config{
 	Recommit:                2 * time.Second,
 	EnablePrefetch:          true,
 	PrefetchGasLimitPercent: 100, // 100% of header gas limit
+
+	DisablePendingBlock: false,
 }
 
 // Miner is the main object which takes care of submitting new work to consensus

miner/worker.go

@@ -832,6 +832,13 @@ func (w *worker) mainLoop() {
 	for {
 		select {
 		case req := <-w.newWorkCh:
+			// When DisablePendingBlock is set and the worker is not actively producing
+			// blocks (non-validator), skip commitWork entirely — its only purpose in
+			// that case is to maintain the pending block snapshot for RPC.
+			if w.config.DisablePendingBlock && !w.IsRunning() {
+				continue
+			}
+
 			if w.chainConfig.ChainID.Cmp(params.BorMainnetChainConfig.ChainID) == 0 || w.chainConfig.ChainID.Cmp(params.MumbaiChainConfig.ChainID) == 0 || w.chainConfig.ChainID.Cmp(params.AmoyChainConfig.ChainID) == 0 {
 				if w.eth.PeerCount() > 0 || devFakeAuthor {
 					//nolint:contextcheck
@@ -852,7 +859,7 @@ func (w *worker) mainLoop() {
 			// already included in the current sealing block. These transactions will
 			// be automatically eliminated.
 			// nolint : nestif
-			if !w.IsRunning() && w.current != nil {
+			if !w.IsRunning() && !w.config.DisablePendingBlock && w.current != nil {
 				// If block is already full, abort
 				if gp := w.current.gasPool; gp != nil && gp.Gas() < params.TxGas {
 					continue

miner/worker_test.go

@@ -2967,3 +2967,43 @@ func TestDelayFlagOffByOne(t *testing.T) {
 	require.True(t, buggyDelayFlag(), "bug: last tx skipped, DAG hint incorrectly embedded")
 	require.False(t, fixedDelayFlag(), "fix: last tx detected, DAG hint suppressed")
 }
+
+// TestDisablePendingBlock validates if setting `DisablePendingBlock` affects the
+// creation of pending block or not.
+func TestDisablePendingBlock(t *testing.T) {
+	t.Parallel()
+
+	t.Run("pending block is nil when flag is enabled", func(t *testing.T) {
+		config := DefaultTestConfig()
+		config.DisablePendingBlock = true
+
+		w, _, cleanup := newTestWorker(t, config, ethashChainConfig, ethash.NewFaker(), rawdb.NewMemoryDatabase(), false, 0)
+		defer cleanup()
+
+		// Trigger the pending block build (non-validator path: worker is not started/running).
+		w.startCh <- struct{}{}
+		time.Sleep(500 * time.Millisecond)
+
+		block, receipts, stateDB := w.pending()
+		require.Nil(t, block, "pending block should be nil when DisablePendingBlock is true")
+		require.Nil(t, receipts, "pending receipts should be nil when DisablePendingBlock is true")
+		require.Nil(t, stateDB, "pending state should be nil when DisablePendingBlock is true")
+	})
+
+	t.Run("pending block is created when flag is disabled", func(t *testing.T) {
+		config := DefaultTestConfig()
+		config.DisablePendingBlock = false
+
+		w, _, cleanup := newTestWorker(t, config, ethashChainConfig, ethash.NewFaker(), rawdb.NewMemoryDatabase(), false, 0)
+		defer cleanup()
+
+		// Trigger the pending block build (non-validator path: worker is not started/running).
+		w.startCh <- struct{}{}
+		time.Sleep(500 * time.Millisecond)
+
+		block, receipts, stateDB := w.pending()
+		require.NotNil(t, block, "pending block should not be nil when DisablePendingBlock is false")
+		require.NotNil(t, receipts, "pending receipts should not be nil when DisablePendingBlock is false")
+		require.NotNil(t, stateDB, "pending state should not be nil when DisablePendingBlock is false")
+	})
+}