support new heads polling over http rpc client (#14373)

* add functions for newHead polling

* add new flag, NewHeadsPollInterval

* fix test

* fix test

* step for adding polling new head impelmentation and sync+outOfSync loop handling logic. To add unit test

* fix lint

* add unit test

* update changeset

* update comments

* simplify step 1, need to fix test

* remove tests, no longer needed

* fix lint

* fix mock

* fix simulated client

* update interface

* rm more

* temp update for testing log level

* temp update

* revert modification to polygon toml

* enable heap monitoring

* enable for testing

* revert

* Dmytro's comments

* make func private

* fix test

* add polling support for SubscribeNewHeaddocke

* update log level

.changeset/happy-feet-rhyme.md

@@ -0,0 +1,11 @@
+---
+"chainlink": minor
+---
+
+This PR introduce few changes:
+- Add a new config option `EVM.NodePool.NewHeadsPollInterval` (0 by default indicate disabled), which is an interval for polling new block periodically using http client rather than subscribe to ws feed. 
+- Updated new head handler for polling new head over http, and register the subscription in node lifecycle logic.
+- If the polling new heads is enabled, WS new heads subscription will be replaced with the new http based polling.
+
+Note: There will be another PR for making WS URL optional with some extra condition.
+#added

common/client/node.go

@@ -45,6 +45,7 @@ type NodeConfig interface {
 	FinalizedBlockPollInterval() time.Duration
 	EnforceRepeatableRead() bool
 	DeathDeclarationDelay() time.Duration
+	NewHeadsPollInterval() time.Duration
 }
 
 type ChainConfig interface {

common/client/node_test.go

@@ -20,6 +20,11 @@ type testNodeConfig struct {
 	enforceRepeatableRead      bool
 	finalizedBlockPollInterval time.Duration
 	deathDeclarationDelay      time.Duration
+	newHeadsPollInterval       time.Duration
+}
+
+func (n testNodeConfig) NewHeadsPollInterval() time.Duration {
+	return n.newHeadsPollInterval
 }
 
 func (n testNodeConfig) PollFailureThreshold() uint32 {

core/chains/evm/client/config_builder.go

@@ -43,7 +43,7 @@ func NewClientConfigs(
 	deathDeclarationDelay time.Duration,
 	noNewFinalizedHeadsThreshold time.Duration,
 	finalizedBlockPollInterval time.Duration,
-
+	newHeadsPollInterval time.Duration,
 ) (commonclient.ChainConfig, evmconfig.NodePool, []*toml.Node, error) {
 	nodes, err := parseNodeConfigs(nodeCfgs)
 	if err != nil {
@@ -59,6 +59,7 @@ func NewClientConfigs(
 		EnforceRepeatableRead:      enforceRepeatableRead,
 		DeathDeclarationDelay:      commonconfig.MustNewDuration(deathDeclarationDelay),
 		FinalizedBlockPollInterval: commonconfig.MustNewDuration(finalizedBlockPollInterval),
+		NewHeadsPollInterval:       commonconfig.MustNewDuration(newHeadsPollInterval),
 	}
 	nodePoolCfg := &evmconfig.NodePoolConfig{C: nodePool}
 	chainConfig := &evmconfig.EVMConfig{

core/chains/evm/client/config_builder_test.go

@@ -37,9 +37,11 @@ func TestClientConfigBuilder(t *testing.T) {
 	finalityDepth := ptr(uint32(10))
 	finalityTagEnabled := ptr(true)
 	noNewHeadsThreshold := time.Second
+	newHeadsPollInterval := 0 * time.Second
 	chainCfg, nodePool, nodes, err := client.NewClientConfigs(selectionMode, leaseDuration, chainTypeStr, nodeConfigs,
 		pollFailureThreshold, pollInterval, syncThreshold, nodeIsSyncingEnabled, noNewHeadsThreshold, finalityDepth,
-		finalityTagEnabled, finalizedBlockOffset, enforceRepeatableRead, deathDeclarationDelay, noNewFinalizedBlocksThreshold, pollInterval)
+		finalityTagEnabled, finalizedBlockOffset, enforceRepeatableRead, deathDeclarationDelay, noNewFinalizedBlocksThreshold,
+		pollInterval, newHeadsPollInterval)
 	require.NoError(t, err)
 
 	// Validate node pool configs
@@ -52,6 +54,7 @@ func TestClientConfigBuilder(t *testing.T) {
 	require.Equal(t, *enforceRepeatableRead, nodePool.EnforceRepeatableRead())
 	require.Equal(t, deathDeclarationDelay, nodePool.DeathDeclarationDelay())
 	require.Equal(t, pollInterval, nodePool.FinalizedBlockPollInterval())
+	require.Equal(t, newHeadsPollInterval, nodePool.NewHeadsPollInterval())
 
 	// Validate node configs
 	require.Equal(t, *nodeConfigs[0].Name, *nodes[0].Name)

core/chains/evm/client/evm_client.go

@@ -22,13 +22,13 @@ func NewEvmClient(cfg evmconfig.NodePool, chainCfg commonclient.ChainConfig, cli
 	for i, node := range nodes {
 		if node.SendOnly != nil && *node.SendOnly {
 			rpc := NewRPCClient(lggr, empty, (*url.URL)(node.HTTPURL), *node.Name, int32(i), chainID,
-				commonclient.Secondary, cfg.FinalizedBlockPollInterval(), largePayloadRPCTimeout, defaultRPCTimeout, chainType)
+				commonclient.Secondary, cfg.FinalizedBlockPollInterval(), cfg.NewHeadsPollInterval(), largePayloadRPCTimeout, defaultRPCTimeout, chainType)
 			sendonly := commonclient.NewSendOnlyNode(lggr, (url.URL)(*node.HTTPURL),
 				*node.Name, chainID, rpc)
 			sendonlys = append(sendonlys, sendonly)
 		} else {
 			rpc := NewRPCClient(lggr, (url.URL)(*node.WSURL), (*url.URL)(node.HTTPURL), *node.Name, int32(i),
-				chainID, commonclient.Primary, cfg.FinalizedBlockPollInterval(), largePayloadRPCTimeout, defaultRPCTimeout, chainType)
+				chainID, commonclient.Primary, cfg.FinalizedBlockPollInterval(), cfg.NewHeadsPollInterval(), largePayloadRPCTimeout, defaultRPCTimeout, chainType)
 			primaryNode := commonclient.NewNode(cfg, chainCfg,
 				lggr, (url.URL)(*node.WSURL), (*url.URL)(node.HTTPURL), *node.Name, int32(i), chainID, *node.Order,
 				rpc, "EVM")

core/chains/evm/client/evm_client_test.go

@@ -29,6 +29,7 @@ func TestNewEvmClient(t *testing.T) {
 	deathDeclarationDelay := time.Second * 3
 	noNewFinalizedBlocksThreshold := time.Second * 5
 	finalizedBlockPollInterval := time.Second * 4
+	newHeadsPollInterval := time.Second * 4
 	nodeConfigs := []client.NodeConfig{
 		{
 			Name:    ptr("foo"),
@@ -40,7 +41,8 @@ func TestNewEvmClient(t *testing.T) {
 	finalityTagEnabled := ptr(true)
 	chainCfg, nodePool, nodes, err := client.NewClientConfigs(selectionMode, leaseDuration, chainTypeStr, nodeConfigs,
 		pollFailureThreshold, pollInterval, syncThreshold, nodeIsSyncingEnabled, noNewHeadsThreshold, finalityDepth,
-		finalityTagEnabled, finalizedBlockOffset, enforceRepeatableRead, deathDeclarationDelay, noNewFinalizedBlocksThreshold, finalizedBlockPollInterval)
+		finalityTagEnabled, finalizedBlockOffset, enforceRepeatableRead, deathDeclarationDelay, noNewFinalizedBlocksThreshold,
+		finalizedBlockPollInterval, newHeadsPollInterval)
 	require.NoError(t, err)
 
 	client := client.NewEvmClient(nodePool, chainCfg, nil, logger.Test(t), testutils.FixtureChainID, nodes, chaintype.ChainType(chainTypeStr))

core/chains/evm/client/helpers_test.go

@@ -89,6 +89,7 @@ type TestNodePoolConfig struct {
 	NodeErrors                     config.ClientErrors
 	EnforceRepeatableReadVal       bool
 	NodeDeathDeclarationDelay      time.Duration
+	NodeNewHeadsPollInterval       time.Duration
 }
 
 func (tc TestNodePoolConfig) PollFailureThreshold() uint32 { return tc.NodePollFailureThreshold }
@@ -107,6 +108,10 @@ func (tc TestNodePoolConfig) FinalizedBlockPollInterval() time.Duration {
 	return tc.NodeFinalizedBlockPollInterval
 }
 
+func (tc TestNodePoolConfig) NewHeadsPollInterval() time.Duration {
+	return tc.NodeNewHeadsPollInterval
+}
+
 func (tc TestNodePoolConfig) Errors() config.ClientErrors {
 	return tc.NodeErrors
 }
@@ -140,7 +145,7 @@ func NewChainClientWithTestNode(
 	}
 
 	lggr := logger.Test(t)
-	rpc := NewRPCClient(lggr, *parsed, rpcHTTPURL, "eth-primary-rpc-0", id, chainID, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+	rpc := NewRPCClient(lggr, *parsed, rpcHTTPURL, "eth-primary-rpc-0", id, chainID, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 
 	n := commonclient.NewNode[*big.Int, *evmtypes.Head, RPCClient](
 		nodeCfg, clientMocks.ChainConfig{NoNewHeadsThresholdVal: noNewHeadsThreshold}, lggr, *parsed, rpcHTTPURL, "eth-primary-node-0", id, chainID, 1, rpc, "EVM")
@@ -152,7 +157,7 @@ func NewChainClientWithTestNode(
 			return nil, pkgerrors.Errorf("sendonly ethereum rpc url scheme must be http(s): %s", u.String())
 		}
 		var empty url.URL
-		rpc := NewRPCClient(lggr, empty, &sendonlyRPCURLs[i], fmt.Sprintf("eth-sendonly-rpc-%d", i), id, chainID, commonclient.Secondary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := NewRPCClient(lggr, empty, &sendonlyRPCURLs[i], fmt.Sprintf("eth-sendonly-rpc-%d", i), id, chainID, commonclient.Secondary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		s := commonclient.NewSendOnlyNode[*big.Int, RPCClient](
 			lggr, u, fmt.Sprintf("eth-sendonly-%d", i), chainID, rpc)
 		sendonlys = append(sendonlys, s)

core/chains/evm/client/rpc_client.go

@@ -123,6 +123,7 @@ type rpcClient struct {
 	largePayloadRpcTimeout     time.Duration
 	rpcTimeout                 time.Duration
 	finalizedBlockPollInterval time.Duration
+	newHeadsPollInterval       time.Duration
 	chainType                  chaintype.ChainType
 
 	ws   rawclient
@@ -159,6 +160,7 @@ func NewRPCClient(
 	chainID *big.Int,
 	tier commonclient.NodeTier,
 	finalizedBlockPollInterval time.Duration,
+	newHeadsPollInterval time.Duration,
 	largePayloadRpcTimeout time.Duration,
 	rpcTimeout time.Duration,
 	chainType chaintype.ChainType,
@@ -174,6 +176,7 @@ func NewRPCClient(
 	r.tier = tier
 	r.ws.uri = wsuri
 	r.finalizedBlockPollInterval = finalizedBlockPollInterval
+	r.newHeadsPollInterval = newHeadsPollInterval
 	if httpuri != nil {
 		r.http = &rawclient{uri: *httpuri}
 	}
@@ -490,6 +493,18 @@ func (r *rpcClient) SubscribeNewHead(ctx context.Context, channel chan<- *evmtyp
 	args := []interface{}{"newHeads"}
 	lggr := r.newRqLggr().With("args", args)
 
+	if r.newHeadsPollInterval > 0 {
+		interval := r.newHeadsPollInterval
+		timeout := interval
+		poller, _ := commonclient.NewPoller[*evmtypes.Head](interval, r.latestBlock, timeout, r.rpcLog)
+		if err = poller.Start(ctx); err != nil {
+			return nil, err
+		}
+
+		lggr.Debugf("Polling new heads over http")
+		return &poller, nil
+	}
+
 	lggr.Debug("RPC call: evmclient.Client#EthSubscribe")
 	start := time.Now()
 	defer func() {
@@ -523,6 +538,19 @@ func (r *rpcClient) SubscribeToHeads(ctx context.Context) (ch <-chan *evmtypes.H
 	start := time.Now()
 	lggr := r.newRqLggr().With("args", args)
 
+	// if new head based on http polling is enabled, we will replace it for WS newHead subscription
+	if r.newHeadsPollInterval > 0 {
+		interval := r.newHeadsPollInterval
+		timeout := interval
+		poller, channel := commonclient.NewPoller[*evmtypes.Head](interval, r.latestBlock, timeout, r.rpcLog)
+		if err = poller.Start(ctx); err != nil {
+			return nil, nil, err
+		}
+
+		lggr.Debugf("Polling new heads over http")
+		return channel, &poller, nil
+	}
+
 	lggr.Debug("RPC call: evmclient.Client#EthSubscribe")
 	defer func() {
 		duration := time.Since(start)
@@ -695,6 +723,10 @@ func (r *rpcClient) LatestFinalizedBlock(ctx context.Context) (head *evmtypes.He
 	return
 }
 
+func (r *rpcClient) latestBlock(ctx context.Context) (head *evmtypes.Head, err error) {
+	return r.BlockByNumber(ctx, nil)
+}
+
 func (r *rpcClient) astarLatestFinalizedBlock(ctx context.Context, result interface{}) (err error) {
 	var hashResult string
 	err = r.CallContext(ctx, &hashResult, "chain_getFinalizedHead")

core/chains/evm/client/rpc_client_test.go

@@ -61,7 +61,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 		server := testutils.NewWSServer(t, chainId, serverCallBack)
 		wsURL := server.WSURL()
 
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		// set to default values
@@ -111,7 +111,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 		server := testutils.NewWSServer(t, chainId, serverCallBack)
 		wsURL := server.WSURL()
 
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		ch := make(chan *evmtypes.Head)
@@ -136,7 +136,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 		server := testutils.NewWSServer(t, chainId, serverCallBack)
 		wsURL := server.WSURL()
 
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		var wg sync.WaitGroup
@@ -160,7 +160,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 	t.Run("Block's chain ID matched configured", func(t *testing.T) {
 		server := testutils.NewWSServer(t, chainId, serverCallBack)
 		wsURL := server.WSURL()
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		ch := make(chan *evmtypes.Head)
@@ -177,7 +177,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 		})
 		wsURL := server.WSURL()
 		observedLggr, observed := logger.TestObserved(t, zap.DebugLevel)
-		rpc := client.NewRPCClient(observedLggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(observedLggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		require.NoError(t, rpc.Dial(ctx))
 		server.Close()
 		_, err := rpc.SubscribeNewHead(ctx, make(chan *evmtypes.Head))
@@ -187,7 +187,7 @@ func TestRPCClient_SubscribeNewHead(t *testing.T) {
 	t.Run("Subscription error is properly wrapper", func(t *testing.T) {
 		server := testutils.NewWSServer(t, chainId, serverCallBack)
 		wsURL := server.WSURL()
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		sub, err := rpc.SubscribeNewHead(ctx, make(chan *evmtypes.Head))
@@ -215,7 +215,7 @@ func TestRPCClient_SubscribeFilterLogs(t *testing.T) {
 		})
 		wsURL := server.WSURL()
 		observedLggr, observed := logger.TestObserved(t, zap.DebugLevel)
-		rpc := client.NewRPCClient(observedLggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(observedLggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		require.NoError(t, rpc.Dial(ctx))
 		server.Close()
 		_, err := rpc.SubscribeFilterLogs(ctx, ethereum.FilterQuery{}, make(chan types.Log))
@@ -232,7 +232,7 @@ func TestRPCClient_SubscribeFilterLogs(t *testing.T) {
 			return resp
 		})
 		wsURL := server.WSURL()
-		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+		rpc := client.NewRPCClient(lggr, *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 		defer rpc.Close()
 		require.NoError(t, rpc.Dial(ctx))
 		sub, err := rpc.SubscribeFilterLogs(ctx, ethereum.FilterQuery{}, make(chan types.Log))
@@ -281,7 +281,7 @@ func TestRPCClient_LatestFinalizedBlock(t *testing.T) {
 	}
 
 	server := createRPCServer()
-	rpc := client.NewRPCClient(lggr, *server.URL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
+	rpc := client.NewRPCClient(lggr, *server.URL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, "")
 	require.NoError(t, rpc.Dial(ctx))
 	defer rpc.Close()
 	server.Head = &evmtypes.Head{Number: 128}
@@ -391,7 +391,7 @@ func TestRpcClientLargePayloadTimeout(t *testing.T) {
 			// use something unreasonably large for RPC timeout to ensure that we use largePayloadRPCTimeout
 			const rpcTimeout = time.Hour
 			const largePayloadRPCTimeout = tests.TestInterval
-			rpc := client.NewRPCClient(logger.Test(t), *rpcURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, largePayloadRPCTimeout, rpcTimeout, "")
+			rpc := client.NewRPCClient(logger.Test(t), *rpcURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, largePayloadRPCTimeout, rpcTimeout, "")
 			require.NoError(t, rpc.Dial(ctx))
 			defer rpc.Close()
 			err := testCase.Fn(ctx, rpc)
@@ -431,7 +431,7 @@ func TestAstarCustomFinality(t *testing.T) {
 
 	const expectedFinalizedBlockNumber = int64(4)
 	const expectedFinalizedBlockHash = "0x7441e97acf83f555e0deefef86db636bc8a37eb84747603412884e4df4d22804"
-	rpcClient := client.NewRPCClient(logger.Test(t), *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, chaintype.ChainAstar)
+	rpcClient := client.NewRPCClient(logger.Test(t), *wsURL, nil, "rpc", 1, chainId, commonclient.Primary, 0, 0, commonclient.QueryTimeout, commonclient.QueryTimeout, chaintype.ChainAstar)
 	defer rpcClient.Close()
 	err := rpcClient.Dial(tests.Context(t))
 	require.NoError(t, err)

core/chains/evm/config/chain_scoped_node_pool.go

@@ -38,6 +38,10 @@ func (n *NodePoolConfig) FinalizedBlockPollInterval() time.Duration {
 	return n.C.FinalizedBlockPollInterval.Duration()
 }
 
+func (n *NodePoolConfig) NewHeadsPollInterval() time.Duration {
+	return n.C.NewHeadsPollInterval.Duration()
+}
+
 func (n *NodePoolConfig) Errors() ClientErrors { return &clientErrorsConfig{c: n.C.Errors} }
 
 func (n *NodePoolConfig) EnforceRepeatableRead() bool {

core/chains/evm/config/config.go

@@ -179,6 +179,7 @@ type NodePool interface {
 	Errors() ClientErrors
 	EnforceRepeatableRead() bool
 	DeathDeclarationDelay() time.Duration
+	NewHeadsPollInterval() time.Duration
 }
 
 // TODO BCF-2509 does the chainscopedconfig really need the entire app config?

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

@@ -875,6 +875,7 @@ type NodePool struct {
 	Errors                     ClientErrors `toml:",omitempty"`
 	EnforceRepeatableRead      *bool
 	DeathDeclarationDelay      *commonconfig.Duration
+	NewHeadsPollInterval       *commonconfig.Duration
 }
 
 func (p *NodePool) setFrom(f *NodePool) {
@@ -907,6 +908,11 @@ func (p *NodePool) setFrom(f *NodePool) {
 	if v := f.DeathDeclarationDelay; v != nil {
 		p.DeathDeclarationDelay = v
 	}
+
+	if v := f.NewHeadsPollInterval; v != nil {
+		p.NewHeadsPollInterval = v
+	}
+
 	p.Errors.setFrom(&f.Errors)
 }
 

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

@@ -77,6 +77,7 @@ NodeIsSyncingEnabled = false
 FinalizedBlockPollInterval = '5s'
 EnforceRepeatableRead = false
 DeathDeclarationDelay = '10s'
+NewHeadsPollInterval = '0s'
 
 [OCR]
 ContractConfirmations = 4

core/config/docs/chains-evm.toml

@@ -408,6 +408,10 @@ EnforceRepeatableRead = false # Default
 # trigger declaration of `FinalizedBlockOutOfSync` due to insignificant network delays in broadcasting of the finalized state among RPCs.
 # RPC will not be picked to handle a request even if this option is set to a nonzero value.
 DeathDeclarationDelay = '10s' # Default
+# NewHeadsPollInterval define an interval for polling new block periodically using http client rather than subscribe to ws feed
+#
+# Set to 0 to disable.
+NewHeadsPollInterval = '0s' # Default
 # **ADVANCED**
 # Errors enable the node to provide custom regex patterns to match against error messages from RPCs.
 [EVM.NodePool.Errors]

core/services/chainlink/config_test.go

@@ -603,6 +603,7 @@ func TestConfig_Marshal(t *testing.T) {
 					FinalizedBlockPollInterval: &second,
 					EnforceRepeatableRead:      ptr(true),
 					DeathDeclarationDelay:      &minute,
+					NewHeadsPollInterval:       &zeroSeconds,
 					Errors: evmcfg.ClientErrors{
 						NonceTooLow:                       ptr[string]("(: |^)nonce too low"),
 						NonceTooHigh:                      ptr[string]("(: |^)nonce too high"),
@@ -1080,6 +1081,7 @@ NodeIsSyncingEnabled = true
 FinalizedBlockPollInterval = '1s'
 EnforceRepeatableRead = true
 DeathDeclarationDelay = '1m0s'
+NewHeadsPollInterval = '0s'
 
 [EVM.NodePool.Errors]
 NonceTooLow = '(: |^)nonce too low'

core/services/chainlink/testdata/config-full.toml

@@ -368,6 +368,7 @@ NodeIsSyncingEnabled = true
 FinalizedBlockPollInterval = '1s'
 EnforceRepeatableRead = true
 DeathDeclarationDelay = '1m0s'
+NewHeadsPollInterval = '0s'
 
 [EVM.NodePool.Errors]
 NonceTooLow = '(: |^)nonce too low'