config to disable outgoing periodic gossip and pull gossip appRequests

plugin/evm/config/config.go

@@ -168,6 +168,7 @@ type Config struct {
 	PullGossipFrequency       Duration `json:"pull-gossip-frequency"`
 	RegossipFrequency         Duration `json:"regossip-frequency"`
 	TxRegossipFrequency       Duration `json:"tx-regossip-frequency"` // Deprecated: use RegossipFrequency instead
+	DisableGossip             bool     `json:"disable-gossip"`        // If true, disables gossiping of transactions
 
 	// Log
 	LogLevel      string `json:"log-level"`

plugin/evm/gossip.go

@@ -88,6 +88,9 @@ func (t txGossipHandler) AppGossip(ctx context.Context, nodeID ids.NodeID, gossi
 }
 
 func (t txGossipHandler) AppRequest(ctx context.Context, nodeID ids.NodeID, deadline time.Time, requestBytes []byte) ([]byte, *common.AppError) {
+	if t.appRequestHandler == nil {
+		return nil, nil
+	}
 	return t.appRequestHandler.AppRequest(ctx, nodeID, deadline, requestBytes)
 }
 

plugin/evm/gossiper_eth_gossiping_test.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"crypto/ecdsa"
 	"encoding/json"
+	"fmt"
 	"math/big"
 	"strings"
 	"sync"
@@ -22,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/ava-labs/coreth/core"
 	"github.com/ava-labs/coreth/core/types"
@@ -73,6 +75,11 @@ func getValidEthTxs(key *ecdsa.PrivateKey, count int, gasPrice *big.Int) []*type
 // show that a geth tx discovered from gossip is requested to the same node that
 // gossiped it
 func TestMempoolEthTxsAppGossipHandling(t *testing.T) {
+	testMempoolEthTxsAppGossipHandling(t, false)
+	testMempoolEthTxsAppGossipHandling(t, true)
+}
+
+func testMempoolEthTxsAppGossipHandling(t *testing.T, disabled bool) {
 	assert := assert.New(t)
 
 	key, err := crypto.GenerateKey()
@@ -83,7 +90,8 @@ func TestMempoolEthTxsAppGossipHandling(t *testing.T) {
 	genesisJSON, err := fundAddressByGenesis([]common.Address{addr})
 	assert.NoError(err)
 
-	_, vm, _, _, sender := GenesisVM(t, true, genesisJSON, "", "")
+	config := fmt.Sprintf(`{"disable-gossip":%v}`, disabled)
+	_, vm, _, _, sender := GenesisVM(t, true, genesisJSON, config, "")
 	defer func() {
 		err := vm.Shutdown(context.Background())
 		assert.NoError(err)
@@ -116,10 +124,11 @@ func TestMempoolEthTxsAppGossipHandling(t *testing.T) {
 	assert.False(txRequested, "tx should not be requested")
 
 	// wait for transaction to be re-gossiped
-	attemptAwait(t, &wg, 5*time.Second)
+	got := attemptAwait(&wg, 5*time.Second)
+	require.Equal(t, !disabled, got)
 }
 
-func attemptAwait(t *testing.T, wg *sync.WaitGroup, delay time.Duration) {
+func attemptAwait(wg *sync.WaitGroup, delay time.Duration) bool {
 	ticker := make(chan struct{})
 
 	// Wait for [wg] and then close [ticket] to indicate that
@@ -131,8 +140,8 @@ func attemptAwait(t *testing.T, wg *sync.WaitGroup, delay time.Duration) {
 
 	select {
 	case <-time.After(delay):
-		t.Fatal("Timed out waiting for wait group to complete")
+		return false // Didn't get the tx
 	case <-ticker:
-		// The wait group completed without issue
+		return true // Got the tx
 	}
 }

plugin/evm/vm.go

@@ -1079,7 +1079,7 @@ func (vm *VM) initBlockBuilding() error {
 	}
 
 	ethTxPushGossiper := vm.ethTxPushGossiper.Get()
-	if ethTxPushGossiper == nil {
+	if ethTxPushGossiper == nil && !vm.config.DisableGossip {
 		ethTxPushGossiper, err = gossip.NewPushGossiper[*GossipEthTx](
 			ethTxGossipMarshaller,
 			ethTxPool,
@@ -1098,7 +1098,7 @@ func (vm *VM) initBlockBuilding() error {
 		vm.ethTxPushGossiper.Set(ethTxPushGossiper)
 	}
 
-	if vm.atomicTxPushGossiper == nil {
+	if vm.atomicTxPushGossiper == nil && !vm.config.DisableGossip {
 		vm.atomicTxPushGossiper, err = gossip.NewPushGossiper[*atomic.GossipAtomicTx](
 			atomicTxGossipMarshaller,
 			vm.mempool,
@@ -1121,7 +1121,7 @@ func (vm *VM) initBlockBuilding() error {
 	vm.builder.awaitSubmittedTxs()
 
 	if vm.ethTxGossipHandler == nil {
-		vm.ethTxGossipHandler = newTxGossipHandler[*GossipEthTx](
+		handler := newTxGossipHandler[*GossipEthTx](
 			vm.ctx.Log,
 			ethTxGossipMarshaller,
 			ethTxPool,
@@ -1131,14 +1131,18 @@ func (vm *VM) initBlockBuilding() error {
 			txGossipThrottlingLimit,
 			vm.p2pValidators,
 		)
+		if vm.config.DisableGossip {
+			handler.appRequestHandler = nil // disable responding to pull gossip requests
+		}
+		vm.ethTxGossipHandler = handler
 	}
 
 	if err := vm.Network.AddHandler(p2p.TxGossipHandlerID, vm.ethTxGossipHandler); err != nil {
 		return fmt.Errorf("failed to add eth tx gossip handler: %w", err)
 	}
 
 	if vm.atomicTxGossipHandler == nil {
-		vm.atomicTxGossipHandler = newTxGossipHandler[*atomic.GossipAtomicTx](
+		handler := newTxGossipHandler[*atomic.GossipAtomicTx](
 			vm.ctx.Log,
 			atomicTxGossipMarshaller,
 			vm.mempool,
@@ -1148,12 +1152,20 @@ func (vm *VM) initBlockBuilding() error {
 			txGossipThrottlingLimit,
 			vm.p2pValidators,
 		)
+		if vm.config.DisableGossip {
+			handler.appRequestHandler = nil // disable responding to pull gossip requests
+		}
+		vm.atomicTxGossipHandler = handler
 	}
 
 	if err := vm.Network.AddHandler(p2p.AtomicTxGossipHandlerID, vm.atomicTxGossipHandler); err != nil {
 		return fmt.Errorf("failed to add atomic tx gossip handler: %w", err)
 	}
 
+	if vm.config.DisableGossip {
+		return nil // Disable periodic push and pull gossip
+	}
+
 	if vm.ethTxPullGossiper == nil {
 		ethTxPullGossiper := gossip.NewPullGossiper[*GossipEthTx](
 			vm.ctx.Log,