Add instant seal to omni-node (#10008)

Adds a new `--instant-seal` CLI flag to enable instant seal mode in
omni-node.


fixes #9996

---------

Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Iulian Barbu <[email protected]>

Author: 3 people

cumulus/polkadot-omni-node/lib/src/cli.rs

@@ -16,6 +16,9 @@
 
 //! CLI options of the omni-node. See [`Command`].
 
+/// Default block time for dev mode when using `--dev` flag.
+const DEFAULT_DEV_BLOCK_TIME_MS: u64 = 3000;
+
 use crate::{
 	chain_spec::DiskChainSpecLoader,
 	common::{
@@ -163,9 +166,19 @@ pub struct Cli<Config: CliConfig> {
 	///
 	/// The `--dev` flag sets the `dev_block_time` to a default value of 3000ms unless explicitly
 	/// provided.
-	#[arg(long)]
+	#[arg(long, conflicts_with = "instant_seal")]
 	pub dev_block_time: Option<u64>,
 
+	/// Start a dev node with instant seal.
+	///
+	/// This is a dev option that enables instant sealing, meaning blocks are produced
+	/// immediately when transactions are received, rather than at fixed intervals.
+	/// Using this option won't result in starting or connecting to a parachain network.
+	/// The resulting node will work on its own, running the wasm blob and producing blocks
+	/// instantly upon receiving transactions.
+	#[arg(long, conflicts_with = "dev_block_time")]
+	pub instant_seal: bool,
+
 	/// DEPRECATED: This feature has been stabilized, pLease use `--authoring slot-based` instead.
 	///
 	/// Use slot-based collator which can handle elastic scaling.
@@ -209,6 +222,16 @@ pub struct Cli<Config: CliConfig> {
 	pub(crate) _phantom: PhantomData<Config>,
 }
 
+/// Development sealing mode.
+#[derive(Debug, Clone, Copy)]
+pub(crate) enum DevSealMode {
+	/// Produces blocks immediately upon receiving transactions.
+	InstantSeal,
+	/// Produces blocks at fixed time intervals.
+	/// The u64 parameter represents the block time in milliseconds.
+	ManualSeal(u64),
+}
+
 /// Collator implementation to use.
 #[derive(PartialEq, Debug, ValueEnum, Clone, Copy)]
 pub enum AuthoringPolicy {
@@ -242,6 +265,19 @@ impl<Config: CliConfig> Cli<Config> {
 			enable_statement_store: self.enable_statement_store,
 		}
 	}
+
+	/// Returns the dev seal mode if the node is in dev mode.
+	pub(crate) fn dev_mode(&self) -> Option<DevSealMode> {
+		if self.instant_seal {
+			Some(DevSealMode::InstantSeal)
+		} else if let Some(dev_block_time) = self.dev_block_time {
+			Some(DevSealMode::ManualSeal(dev_block_time))
+		} else if self.run.base.is_dev().unwrap_or(false) {
+			Some(DevSealMode::ManualSeal(DEFAULT_DEV_BLOCK_TIME_MS))
+		} else {
+			None
+		}
+	}
 }
 
 impl<Config: CliConfig> SubstrateCli for Cli<Config> {

cumulus/polkadot-omni-node/lib/src/command.rs

@@ -35,12 +35,10 @@ use clap::{CommandFactory, FromArgMatches};
 use cumulus_client_service::storage_proof_size::HostFunctions as ReclaimHostFunctions;
 use frame_benchmarking_cli::{BenchmarkCmd, SUBSTRATE_REFERENCE_HARDWARE};
 use log::info;
-use sc_cli::{CliConfiguration, Result, SubstrateCli};
+use sc_cli::{Result, SubstrateCli};
 #[cfg(feature = "runtime-benchmarks")]
 use sp_runtime::traits::HashingFor;
 
-const DEFAULT_DEV_BLOCK_TIME_MS: u64 = 3000;
-
 /// Structure that can be used in order to provide customizers for different functionalities of the
 /// node binary that is being built using this library.
 pub struct RunConfig {
@@ -303,17 +301,8 @@ where
 				let node_spec =
 					new_node_spec(&config, &cmd_config.runtime_resolver, &cli.node_extra_args())?;
 
-				if cli.run.base.is_dev()? {
-					let dev_block_time = cli.dev_block_time.unwrap_or(DEFAULT_DEV_BLOCK_TIME_MS);
-					return node_spec
-						.start_manual_seal_node(config, dev_block_time)
-						.map_err(Into::into);
-				}
-
-				if let Some(dev_block_time) = cli.dev_block_time {
-					return node_spec
-						.start_manual_seal_node(config, dev_block_time)
-						.map_err(Into::into);
+				if let Some(dev_mode) = cli.dev_mode() {
+					return node_spec.start_dev_node(config, dev_mode).map_err(Into::into);
 				}
 
 				// If Statemint (Statemine, Westmint, Rockmine) DB exists and we're using the

cumulus/polkadot-omni-node/lib/src/common/spec.rs

@@ -16,6 +16,7 @@
 
 use crate::{
 	chain_spec::Extensions,
+	cli::DevSealMode,
 	common::{
 		command::NodeCommandRunner,
 		rpc::BuildRpcExtensions,
@@ -300,11 +301,11 @@ pub(crate) trait NodeSpec: BaseNodeSpec {
 
 	const SYBIL_RESISTANCE: CollatorSybilResistance;
 
-	fn start_manual_seal_node(
+	fn start_dev_node(
 		_config: Configuration,
-		_block_time: u64,
+		_mode: DevSealMode,
 	) -> sc_service::error::Result<TaskManager> {
-		Err(sc_service::Error::Other("Manual seal not supported for this node type".into()))
+		Err(sc_service::Error::Other("Dev not supported for this node type".into()))
 	}
 
 	/// Start a node with the given parachain spec.
@@ -557,11 +558,11 @@ pub(crate) trait NodeSpec: BaseNodeSpec {
 }
 
 pub(crate) trait DynNodeSpec: NodeCommandRunner {
-	/// Start node with manual-seal consensus.
-	fn start_manual_seal_node(
+	/// Start node with manual or instant seal consensus.
+	fn start_dev_node(
 		self: Box<Self>,
 		config: Configuration,
-		block_time: u64,
+		mode: DevSealMode,
 	) -> sc_service::error::Result<TaskManager>;
 
 	/// Start the node.
@@ -579,12 +580,12 @@ impl<T> DynNodeSpec for T
 where
 	T: NodeSpec + NodeCommandRunner,
 {
-	fn start_manual_seal_node(
+	fn start_dev_node(
 		self: Box<Self>,
 		config: Configuration,
-		block_time: u64,
+		mode: DevSealMode,
 	) -> sc_service::error::Result<TaskManager> {
-		<Self as NodeSpec>::start_manual_seal_node(config, block_time)
+		<Self as NodeSpec>::start_dev_node(config, mode)
 	}
 
 	fn start_node(

cumulus/polkadot-omni-node/lib/src/nodes/aura.rs

@@ -15,7 +15,7 @@
 // limitations under the License.
 
 use crate::{
-	cli::AuthoringPolicy,
+	cli::{AuthoringPolicy, DevSealMode},
 	common::{
 		aura::{AuraIdT, AuraRuntimeApi},
 		rpc::{BuildParachainRpcExtensions, BuildRpcExtensions},
@@ -211,9 +211,9 @@ where
 	type StartConsensus = StartConsensus;
 	const SYBIL_RESISTANCE: CollatorSybilResistance = CollatorSybilResistance::Resistant;
 
-	fn start_manual_seal_node(
+	fn start_dev_node(
 		mut config: Configuration,
-		block_time: u64,
+		mode: DevSealMode,
 	) -> sc_service::error::Result<TaskManager> {
 		let PartialComponents {
 			client,
@@ -277,24 +277,6 @@ where
 			None,
 		);
 
-		let (manual_seal_sink, manual_seal_stream) = futures::channel::mpsc::channel(1024);
-		let mut manual_seal_sink_clone = manual_seal_sink.clone();
-		task_manager
-			.spawn_essential_handle()
-			.spawn("block_authoring", None, async move {
-				loop {
-					futures_timer::Delay::new(std::time::Duration::from_millis(block_time)).await;
-					manual_seal_sink_clone
-						.try_send(sc_consensus_manual_seal::EngineCommand::SealNewBlock {
-							create_empty: true,
-							finalize: true,
-							parent_hash: None,
-							sender: None,
-						})
-						.unwrap();
-				}
-			});
-
 		// Note: Changing slot durations are currently not supported
 		let slot_duration = sc_consensus_aura::slot_duration(&*client)
 			.expect("slot_duration is always present; qed.");
@@ -305,29 +287,67 @@ where
 
 		let para_id =
 			Self::parachain_id(&client, &config).ok_or("Failed to retrieve the parachain id")?;
-		let create_inherent_data_providers = Self::create_manual_seal_inherent_data_providers(
-			client.clone(),
-			para_id,
-			slot_duration,
-		);
-
-		let params = sc_consensus_manual_seal::ManualSealParams {
-			block_import: client.clone(),
-			env: proposer,
-			client: client.clone(),
-			pool: transaction_pool.clone(),
-			select_chain: LongestChain::new(backend.clone()),
-			commands_stream: Box::pin(manual_seal_stream),
-			consensus_data_provider: Some(Box::new(aura_digest_provider)),
-			create_inherent_data_providers,
-		};
-
-		let authorship_future = sc_consensus_manual_seal::run_manual_seal(params);
-		task_manager.spawn_essential_handle().spawn_blocking(
-			"manual-seal",
-			None,
-			authorship_future,
-		);
+		let create_inherent_data_providers =
+			Self::create_dev_node_inherent_data_providers(client.clone(), para_id, slot_duration);
+
+		match mode {
+			DevSealMode::InstantSeal => {
+				let params = sc_consensus_manual_seal::InstantSealParams {
+					block_import: client.clone(),
+					env: proposer,
+					client: client.clone(),
+					pool: transaction_pool.clone(),
+					select_chain: LongestChain::new(backend.clone()),
+					consensus_data_provider: Some(Box::new(aura_digest_provider)),
+					create_inherent_data_providers,
+				};
+
+				let authorship_future = sc_consensus_manual_seal::run_instant_seal(params);
+				task_manager.spawn_essential_handle().spawn_blocking(
+					"instant-seal",
+					None,
+					authorship_future,
+				);
+			},
+			DevSealMode::ManualSeal(block_time) => {
+				let (manual_seal_sink, manual_seal_stream) = futures::channel::mpsc::channel(1024);
+				let mut manual_seal_sink_clone = manual_seal_sink.clone();
+				task_manager
+					.spawn_essential_handle()
+					.spawn("block_authoring", None, async move {
+						loop {
+							futures_timer::Delay::new(std::time::Duration::from_millis(block_time))
+								.await;
+							manual_seal_sink_clone
+								.try_send(sc_consensus_manual_seal::EngineCommand::SealNewBlock {
+									create_empty: true,
+									finalize: true,
+									parent_hash: None,
+									sender: None,
+								})
+								.unwrap();
+						}
+					});
+
+				let params = sc_consensus_manual_seal::ManualSealParams {
+					block_import: client.clone(),
+					env: proposer,
+					client: client.clone(),
+					pool: transaction_pool.clone(),
+					select_chain: LongestChain::new(backend.clone()),
+					commands_stream: Box::pin(manual_seal_stream),
+					consensus_data_provider: Some(Box::new(aura_digest_provider)),
+					create_inherent_data_providers,
+				};
+
+				let authorship_future = sc_consensus_manual_seal::run_manual_seal(params);
+				task_manager.spawn_essential_handle().spawn_blocking(
+					"manual-seal",
+					None,
+					authorship_future,
+				);
+			},
+		}
 
 		let rpc_extensions_builder = {
 			let client = client.clone();
@@ -373,11 +393,11 @@ where
 	RuntimeApi::RuntimeApi: AuraRuntimeApi<Block, AuraId>,
 	AuraId: AuraIdT + Sync,
 {
-	/// Creates the inherent data providers for manual seal consensus.
+	/// Creates the inherent data providers for manual and instant seal consensus.
 	///
 	/// This function sets up the timestamp and parachain validation data providers
-	/// required for manual seal block production in a parachain environment.
-	fn create_manual_seal_inherent_data_providers(
+	/// required for dev seal block production in a parachain environment.
+	fn create_dev_node_inherent_data_providers(
 		client: Arc<ParachainClient<Block, RuntimeApi>>,
 		para_id: ParaId,
 		slot_duration: sp_consensus_aura::SlotDuration,

prdoc/pr_10008.prdoc

@@ -0,0 +1,12 @@
+title: Add instant seal to omni-node
+doc:
+- audience: Runtime Dev
+  description: |-
+    Adds a new `--instant-seal` CLI flag to enable instant seal mode in omni-node. When this flag
+    is passed, blocks are produced immediately upon receiving transactions, rather than at fixed
+    intervals. This flag cannot be used together with `--dev-block-time`.
+
+    fixes https://github.com/paritytech/polkadot-sdk/issues/9996
+crates:
+- name: polkadot-omni-node-lib
+  bump: patch