Integrate litep2p into Polkadot SDK (#2944)

[litep2p](https://github.com/altonen/litep2p) is a libp2p-compatible P2P
networking library. It supports all of the features of `rust-libp2p`
that are currently being utilized by Polkadot SDK.

Compared to `rust-libp2p`, `litep2p` has a quite different architecture
which is why the new `litep2p` network backend is only able to use a
little of the existing code in `sc-network`. The design has been mainly
influenced by how we'd wish to structure our networking-related code in
Polkadot SDK: independent higher-levels protocols directly communicating
with the network over links that support bidirectional backpressure. A
good example would be `NotificationHandle`/`RequestResponseHandle`
abstractions which allow, e.g., `SyncingEngine` to directly communicate
with peers to announce/request blocks.

I've tried running `polkadot --network-backend litep2p` with a few
different peer configurations and there is a noticeable reduction in
networking CPU usage. For high load (`--out-peers 200`), networking CPU
usage goes down from ~110% to ~30% (80 pp) and for normal load
(`--out-peers 40`), the usage goes down from ~55% to ~18% (37 pp).

These should not be taken as final numbers because:

a) there are still some low-hanging optimization fruits, such as
enabling [receive window
auto-tuning](https://github.com/libp2p/rust-yamux/pull/176), integrating
`Peerset` more closely with `litep2p` or improving memory usage of the
WebSocket transport
b) fixing bugs/instabilities that incorrectly cause `litep2p` to do less
work will increase the networking CPU usage
c) verification in a more diverse set of tests/conditions is needed

Nevertheless, these numbers should give an early estimate for CPU usage
of the new networking backend.

This PR consists of three separate changes:
* introduce a generic `PeerId` (wrapper around `Multihash`) so that we
don't have use `NetworkService::PeerId` in every part of the code that
uses a `PeerId`
* introduce `NetworkBackend` trait, implement it for the libp2p network
stack and make Polkadot SDK generic over `NetworkBackend`
  * implement `NetworkBackend` for litep2p

The new library should be considered experimental which is why
`rust-libp2p` will remain as the default option for the time being. This
PR currently depends on the master branch of `litep2p` but I'll cut a
new release for the library once all review comments have been
addresses.

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>
Co-authored-by: Alexandru Vasile <alexandru.vasile@parity.io>

cumulus/polkadot-parachain/src/command.rs

@@ -21,7 +21,7 @@ use crate::{
 	fake_runtime_api::{
 		asset_hub_polkadot_aura::RuntimeApi as AssetHubPolkadotRuntimeApi, aura::RuntimeApi,
 	},
-	service::{new_partial, Block},
+	service::{new_partial, Block, Hash},
 };
 use cumulus_client_service::storage_proof_size::HostFunctions as ReclaimHostFunctions;
 use cumulus_primitives_core::ParaId;
@@ -498,7 +498,6 @@ macro_rules! construct_async_run {
 
 /// Parse command line arguments into service configuration.
 pub fn run() -> Result<()> {
-	use Runtime::*;
 	let cli = Cli::from_args();
 
 	match &cli.subcommand {
@@ -670,151 +669,236 @@ pub fn run() -> Result<()> {
 				info!("Parachain Account: {}", parachain_account);
 				info!("Is collating: {}", if config.role.is_authority() { "yes" } else { "no" });
 
-				match config.chain_spec.runtime()? {
-					AssetHubPolkadot => crate::service::start_asset_hub_node::<
-						AssetHubPolkadotRuntimeApi,
-						AssetHubPolkadotAuraId,
-					>(config, polkadot_config, collator_options, id, hwbench)
-					.await
-					.map(|r| r.0)
-					.map_err(Into::into),
-
-					AssetHubKusama =>
-						crate::service::start_asset_hub_node::<
-							RuntimeApi,
-							AuraId,
-						>(config, polkadot_config, collator_options, id, hwbench)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-				    AssetHubRococo | AssetHubWestend =>
-						crate::service::start_asset_hub_lookahead_node::<
-						RuntimeApi,
-							AuraId,
-						>(config, polkadot_config, collator_options, id, hwbench)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					CollectivesPolkadot =>
-						crate::service::start_generic_aura_node(config, polkadot_config, collator_options, id, hwbench)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					CollectivesWestend =>
-						crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					Seedling | Shell =>
-						crate::service::start_shell_node(
+				match polkadot_config.network.network_backend {
+					sc_network::config::NetworkBackendType::Libp2p =>
+						start_node::<sc_network::NetworkWorker<_, _>>(
 							config,
 							polkadot_config,
 							collator_options,
 							id,
 							hwbench,
 						)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					ContractsRococo => crate::service::start_contracts_rococo_node(
-						config,
-						polkadot_config,
-						collator_options,
-						id,
-						hwbench,
-					)
-					.await
-					.map(|r| r.0)
-					.map_err(Into::into),
-
-					BridgeHub(bridge_hub_runtime_type) => match bridge_hub_runtime_type {
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::Polkadot |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::PolkadotLocal =>
-							crate::service::start_generic_aura_node(config, polkadot_config, collator_options, id, hwbench)
-								.await
-								.map(|r| r.0),
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::Kusama |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::KusamaLocal =>
-							crate::service::start_generic_aura_node(config, polkadot_config, collator_options, id, hwbench)
-							.await
-							.map(|r| r.0),
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::Westend |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::WestendLocal |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::WestendDevelopment =>
-							crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-							.await
-							.map(|r| r.0),
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::Rococo |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::RococoLocal |
-						chain_spec::bridge_hubs::BridgeHubRuntimeType::RococoDevelopment =>
-							crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-							.await
-							.map(|r| r.0),
-					}
-					.map_err(Into::into),
-
-					Coretime(coretime_runtime_type) => match coretime_runtime_type {
-						chain_spec::coretime::CoretimeRuntimeType::Kusama |
-						chain_spec::coretime::CoretimeRuntimeType::KusamaLocal |
-						chain_spec::coretime::CoretimeRuntimeType::Polkadot |
-						chain_spec::coretime::CoretimeRuntimeType::PolkadotLocal |
-						chain_spec::coretime::CoretimeRuntimeType::Rococo |
-						chain_spec::coretime::CoretimeRuntimeType::RococoLocal |
-						chain_spec::coretime::CoretimeRuntimeType::RococoDevelopment |
-						chain_spec::coretime::CoretimeRuntimeType::Westend |
-						chain_spec::coretime::CoretimeRuntimeType::WestendLocal |
-						chain_spec::coretime::CoretimeRuntimeType::WestendDevelopment =>
-							crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-							.await
-							.map(|r| r.0),
-					}
-					.map_err(Into::into),
-
-					Penpal(_) | Default =>
-						crate::service::start_rococo_parachain_node(
+						.await,
+					sc_network::config::NetworkBackendType::Litep2p =>
+						start_node::<sc_network::Litep2pNetworkBackend>(
 							config,
 							polkadot_config,
 							collator_options,
 							id,
 							hwbench,
 						)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					Glutton | GluttonWestend =>
-						crate::service::start_basic_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-						.await
-						.map(|r| r.0)
-						.map_err(Into::into),
-
-					People(people_runtime_type) => match people_runtime_type {
-						chain_spec::people::PeopleRuntimeType::Kusama |
-						chain_spec::people::PeopleRuntimeType::KusamaLocal |
-						chain_spec::people::PeopleRuntimeType::Polkadot |
-						chain_spec::people::PeopleRuntimeType::PolkadotLocal |
-						chain_spec::people::PeopleRuntimeType::Rococo |
-						chain_spec::people::PeopleRuntimeType::RococoLocal |
-						chain_spec::people::PeopleRuntimeType::RococoDevelopment |
-						chain_spec::people::PeopleRuntimeType::Westend |
-						chain_spec::people::PeopleRuntimeType::WestendLocal |
-						chain_spec::people::PeopleRuntimeType::WestendDevelopment =>
-							crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
-							.await
-							.map(|r| r.0),
-					}
-					.map_err(Into::into),
+						.await,
 				}
 			})
 		},
 	}
 }
 
+async fn start_node<Network: sc_network::NetworkBackend<Block, Hash>>(
+	config: sc_service::Configuration,
+	polkadot_config: sc_service::Configuration,
+	collator_options: cumulus_client_cli::CollatorOptions,
+	id: ParaId,
+	hwbench: Option<sc_sysinfo::HwBench>,
+) -> Result<sc_service::TaskManager> {
+	match config.chain_spec.runtime()? {
+		Runtime::AssetHubPolkadot => crate::service::start_asset_hub_node::<
+			AssetHubPolkadotRuntimeApi,
+			AssetHubPolkadotAuraId,
+			Network,
+		>(config, polkadot_config, collator_options, id, hwbench)
+		.await
+		.map(|r| r.0)
+		.map_err(Into::into),
+
+		Runtime::AssetHubKusama => crate::service::start_asset_hub_node::<
+			RuntimeApi,
+			AuraId,
+			Network,
+		>(config, polkadot_config, collator_options, id, hwbench)
+		.await
+		.map(|r| r.0)
+		.map_err(Into::into),
+
+		Runtime::AssetHubRococo | Runtime::AssetHubWestend =>
+			crate::service::start_asset_hub_lookahead_node::<RuntimeApi, AuraId, Network>(
+				config,
+				polkadot_config,
+				collator_options,
+				id,
+				hwbench,
+			)
+			.await
+			.map(|r| r.0)
+			.map_err(Into::into),
+
+		Runtime::CollectivesPolkadot => crate::service::start_generic_aura_node::<Network>(
+			config,
+			polkadot_config,
+			collator_options,
+			id,
+			hwbench,
+		)
+		.await
+		.map(|r| r.0)
+		.map_err(Into::into),
+
+		Runtime::CollectivesWestend =>
+			crate::service::start_generic_aura_lookahead_node::<Network>(
+				config,
+				polkadot_config,
+				collator_options,
+				id,
+				hwbench,
+			)
+			.await
+			.map(|r| r.0)
+			.map_err(Into::into),
+
+		Runtime::Seedling | Runtime::Shell => crate::service::start_shell_node::<Network>(
+			config,
+			polkadot_config,
+			collator_options,
+			id,
+			hwbench,
+		)
+		.await
+		.map(|r| r.0)
+		.map_err(Into::into),
+
+		Runtime::ContractsRococo => crate::service::start_contracts_rococo_node::<Network>(
+			config,
+			polkadot_config,
+			collator_options,
+			id,
+			hwbench,
+		)
+		.await
+		.map(|r| r.0)
+		.map_err(Into::into),
+
+		Runtime::BridgeHub(bridge_hub_runtime_type) => match bridge_hub_runtime_type {
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::Polkadot |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::PolkadotLocal =>
+				crate::service::start_generic_aura_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::Kusama |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::KusamaLocal =>
+				crate::service::start_generic_aura_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::Westend |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::WestendLocal |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::WestendDevelopment =>
+				crate::service::start_generic_aura_lookahead_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::Rococo |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::RococoLocal |
+			chain_spec::bridge_hubs::BridgeHubRuntimeType::RococoDevelopment =>
+				crate::service::start_generic_aura_lookahead_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+		}
+		.map_err(Into::into),
+
+		Runtime::Coretime(coretime_runtime_type) => match coretime_runtime_type {
+			chain_spec::coretime::CoretimeRuntimeType::Kusama |
+			chain_spec::coretime::CoretimeRuntimeType::KusamaLocal |
+			chain_spec::coretime::CoretimeRuntimeType::Polkadot |
+			chain_spec::coretime::CoretimeRuntimeType::PolkadotLocal |
+			chain_spec::coretime::CoretimeRuntimeType::Rococo |
+			chain_spec::coretime::CoretimeRuntimeType::RococoLocal |
+			chain_spec::coretime::CoretimeRuntimeType::RococoDevelopment |
+			chain_spec::coretime::CoretimeRuntimeType::Westend |
+			chain_spec::coretime::CoretimeRuntimeType::WestendLocal |
+			chain_spec::coretime::CoretimeRuntimeType::WestendDevelopment =>
+				crate::service::start_generic_aura_lookahead_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+		}
+		.map_err(Into::into),
+
+		Runtime::Penpal(_) | Runtime::Default =>
+			crate::service::start_rococo_parachain_node::<Network>(
+				config,
+				polkadot_config,
+				collator_options,
+				id,
+				hwbench,
+			)
+			.await
+			.map(|r| r.0)
+			.map_err(Into::into),
+
+		Runtime::Glutton | Runtime::GluttonWestend =>
+			crate::service::start_basic_lookahead_node::<Network>(
+				config,
+				polkadot_config,
+				collator_options,
+				id,
+				hwbench,
+			)
+			.await
+			.map(|r| r.0)
+			.map_err(Into::into),
+
+		Runtime::People(people_runtime_type) => match people_runtime_type {
+			chain_spec::people::PeopleRuntimeType::Kusama |
+			chain_spec::people::PeopleRuntimeType::KusamaLocal |
+			chain_spec::people::PeopleRuntimeType::Polkadot |
+			chain_spec::people::PeopleRuntimeType::PolkadotLocal |
+			chain_spec::people::PeopleRuntimeType::Rococo |
+			chain_spec::people::PeopleRuntimeType::RococoLocal |
+			chain_spec::people::PeopleRuntimeType::RococoDevelopment |
+			chain_spec::people::PeopleRuntimeType::Westend |
+			chain_spec::people::PeopleRuntimeType::WestendLocal |
+			chain_spec::people::PeopleRuntimeType::WestendDevelopment =>
+				crate::service::start_generic_aura_lookahead_node::<Network>(
+					config,
+					polkadot_config,
+					collator_options,
+					id,
+					hwbench,
+				)
+				.await
+				.map(|r| r.0),
+		}
+		.map_err(Into::into),
+	}
+}
+
 impl DefaultConfigurationValues for RelayChainCli {
 	fn p2p_listen_port() -> u16 {
 		30334

cumulus/polkadot-parachain/src/service.rs

@@ -51,7 +51,7 @@ use sc_consensus::{
 	BlockImportParams, ImportQueue,
 };
 use sc_executor::{HeapAllocStrategy, WasmExecutor, DEFAULT_HEAP_ALLOC_STRATEGY};
-use sc_network::{config::FullNetworkConfiguration, NetworkBlock};
+use sc_network::{config::FullNetworkConfiguration, service::traits::NetworkBackend, NetworkBlock};
 use sc_network_sync::SyncingService;
 use sc_service::{Configuration, PartialComponents, TFullBackend, TFullClient, TaskManager};
 use sc_telemetry::{Telemetry, TelemetryHandle, TelemetryWorker, TelemetryWorkerHandle};
@@ -191,7 +191,7 @@ where
 ///
 /// This is the actual implementation that is abstract over the executor and the runtime api.
 #[sc_tracing::logging::prefix_logs_with("Parachain")]
-async fn start_node_impl<RuntimeApi, RB, BIQ, SC>(
+async fn start_node_impl<RuntimeApi, RB, BIQ, SC, Net>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
@@ -244,6 +244,7 @@ where
 		Arc<dyn Fn(Hash, Option<Vec<u8>>) + Send + Sync>,
 		Arc<ParachainBackend>,
 	) -> Result<(), sc_service::Error>,
+	Net: NetworkBackend<Block, Hash>,
 {
 	let parachain_config = prepare_node_config(parachain_config);
 
@@ -269,7 +270,7 @@ where
 	let prometheus_registry = parachain_config.prometheus_registry().cloned();
 	let transaction_pool = params.transaction_pool.clone();
 	let import_queue_service = params.import_queue.service();
-	let net_config = FullNetworkConfiguration::new(&parachain_config.network);
+	let net_config = FullNetworkConfiguration::<_, _, Net>::new(&parachain_config.network);
 
 	let (network, system_rpc_tx, tx_handler_controller, start_network, sync_service) =
 		build_network(BuildNetworkParams {
@@ -423,14 +424,14 @@ pub fn build_aura_import_queue(
 }
 
 /// Start a rococo parachain node.
-pub async fn start_rococo_parachain_node(
+pub async fn start_rococo_parachain_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -492,14 +493,14 @@ fn build_contracts_rpc_extensions(
 }
 
 /// Start a polkadot-shell parachain node.
-pub async fn start_shell_node(
+pub async fn start_shell_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -687,14 +688,14 @@ where
 }
 
 /// Start an aura powered parachain node. Some system chains use this.
-pub async fn start_generic_aura_node(
+pub async fn start_generic_aura_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -768,14 +769,14 @@ pub async fn start_generic_aura_node(
 /// Uses the lookahead collator to support async backing.
 ///
 /// Start an aura powered parachain node. Some system chains use this.
-pub async fn start_generic_aura_lookahead_node(
+pub async fn start_generic_aura_lookahead_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -792,7 +793,7 @@ pub async fn start_generic_aura_lookahead_node(
 /// Start a shell node which should later transition into an Aura powered parachain node. Asset Hub
 /// uses this because at genesis, Asset Hub was on the `shell` runtime which didn't have Aura and
 /// needs to sync and upgrade before it can run `AuraApi` functions.
-pub async fn start_asset_hub_node<RuntimeApi, AuraId: AppCrypto + Send + Codec + Sync>(
+pub async fn start_asset_hub_node<RuntimeApi, AuraId: AppCrypto + Send + Codec + Sync, Net>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
@@ -813,8 +814,9 @@ where
 		+ frame_rpc_system::AccountNonceApi<Block, AccountId, Nonce>,
 	<<AuraId as AppCrypto>::Pair as Pair>::Signature:
 		TryFrom<Vec<u8>> + std::hash::Hash + sp_runtime::traits::Member + Codec,
+	Net: NetworkBackend<Block, Hash>,
 {
-	start_node_impl::<RuntimeApi, _, _, _>(
+	start_node_impl::<RuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -940,7 +942,11 @@ where
 ///
 /// Uses the lookahead collator to support async backing.
 #[sc_tracing::logging::prefix_logs_with("Parachain")]
-pub async fn start_asset_hub_lookahead_node<RuntimeApi, AuraId: AppCrypto + Send + Codec + Sync>(
+pub async fn start_asset_hub_lookahead_node<
+	RuntimeApi,
+	AuraId: AppCrypto + Send + Codec + Sync,
+	Net,
+>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
@@ -962,8 +968,9 @@ where
 		+ cumulus_primitives_aura::AuraUnincludedSegmentApi<Block>,
 	<<AuraId as AppCrypto>::Pair as Pair>::Signature:
 		TryFrom<Vec<u8>> + std::hash::Hash + sp_runtime::traits::Member + Codec,
+	Net: NetworkBackend<Block, Hash>,
 {
-	start_node_impl::<RuntimeApi, _, _, _>(
+	start_node_impl::<RuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -1213,14 +1220,14 @@ fn start_lookahead_aura_consensus(
 /// Start an aura powered parachain node which uses the lookahead collator to support async backing.
 /// This node is basic in the sense that its runtime api doesn't include common contents such as
 /// transaction payment. Used for aura glutton.
-pub async fn start_basic_lookahead_node(
+pub async fn start_basic_lookahead_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,
@@ -1235,14 +1242,14 @@ pub async fn start_basic_lookahead_node(
 }
 
 /// Start a parachain node for Rococo Contracts.
-pub async fn start_contracts_rococo_node(
+pub async fn start_contracts_rococo_node<Net: NetworkBackend<Block, Hash>>(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
 	para_id: ParaId,
 	hwbench: Option<sc_sysinfo::HwBench>,
 ) -> sc_service::error::Result<(TaskManager, Arc<ParachainClient<FakeRuntimeApi>>)> {
-	start_node_impl::<FakeRuntimeApi, _, _, _>(
+	start_node_impl::<FakeRuntimeApi, _, _, _, Net>(
 		parachain_config,
 		polkadot_config,
 		collator_options,