Enable async backing on all testnet system chains (paritytech#2949)

Built on top of paritytech#2826
which was a trial run.

Guide:
https://github.com/w3f/polkadot-wiki/blob/master/docs/maintain/maintain-guides-async-backing.md

---------

Signed-off-by: georgepisaltu <george.pisaltu@parity.io>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Dónal Murray <donal.murray@parity.io>
Co-authored-by: Dmitry Sinyavin <dmitry.sinyavin@parity.io>
Co-authored-by: s0me0ne-unkn0wn <48632512+s0me0ne-unkn0wn@users.noreply.github.com>
Co-authored-by: Svyatoslav Nikolsky <svyatonik@gmail.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: georgepisaltu <52418509+georgepisaltu@users.noreply.github.com>

bridges/primitives/chain-bridge-hub-cumulus/src/lib.rs

@@ -57,6 +57,12 @@ const MAXIMUM_BLOCK_WEIGHT: Weight = Weight::from_parts(constants::WEIGHT_REF_TI
 	.saturating_div(2)
 	.set_proof_size(polkadot_primitives::MAX_POV_SIZE as u64);
 
+/// We allow for 2 seconds of compute with a 6 second average block.
+const MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING: Weight = Weight::from_parts(
+	constants::WEIGHT_REF_TIME_PER_SECOND.saturating_mul(2),
+	polkadot_primitives::MAX_POV_SIZE as u64,
+);
+
 /// All cumulus bridge hubs assume that about 5 percent of the block weight is consumed by
 /// `on_initialize` handlers. This is used to limit the maximal weight of a single extrinsic.
 ///
@@ -96,6 +102,26 @@ parameter_types! {
 		})
 		.avg_block_initialization(AVERAGE_ON_INITIALIZE_RATIO)
 		.build_or_panic();
+
+	/// Weight limit of the Cumulus-based bridge hub blocks when async backing is enabled.
+	pub BlockWeightsForAsyncBacking: limits::BlockWeights = limits::BlockWeights::builder()
+		.base_block(BlockExecutionWeight::get())
+		.for_class(DispatchClass::all(), |weights| {
+			weights.base_extrinsic = ExtrinsicBaseWeight::get();
+		})
+		.for_class(DispatchClass::Normal, |weights| {
+			weights.max_total = Some(NORMAL_DISPATCH_RATIO * MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING);
+		})
+		.for_class(DispatchClass::Operational, |weights| {
+			weights.max_total = Some(MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING);
+			// Operational transactions have an extra reserved space, so that they
+			// are included even if block reached `MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING`.
+			weights.reserved = Some(
+				MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING - NORMAL_DISPATCH_RATIO * MAXIMUM_BLOCK_WEIGHT_FOR_ASYNC_BACKING,
+			);
+		})
+		.avg_block_initialization(AVERAGE_ON_INITIALIZE_RATIO)
+		.build_or_panic();
 }
 
 /// Public key of the chain account that may be used to verify signatures.

bridges/primitives/chain-bridge-hub-rococo/src/lib.rs

@@ -50,7 +50,7 @@ impl Chain for BridgeHubRococo {
 	}
 
 	fn max_extrinsic_weight() -> Weight {
-		BlockWeights::get()
+		BlockWeightsForAsyncBacking::get()
 			.get(DispatchClass::Normal)
 			.max_extrinsic
 			.unwrap_or(Weight::MAX)

bridges/primitives/chain-bridge-hub-westend/src/lib.rs

@@ -49,7 +49,7 @@ impl Chain for BridgeHubWestend {
 	}
 
 	fn max_extrinsic_weight() -> Weight {
-		BlockWeights::get()
+		BlockWeightsForAsyncBacking::get()
 			.get(DispatchClass::Normal)
 			.max_extrinsic
 			.unwrap_or(Weight::MAX)

cumulus/pallets/collator-selection/src/benchmarking.rs

@@ -394,7 +394,7 @@ mod benchmarks {
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
 
-		let new_block: BlockNumberFor<T> = 1800u32.into();
+		let new_block: BlockNumberFor<T> = T::KickThreshold::get();
 		let zero_block: BlockNumberFor<T> = 0u32.into();
 		let candidates: Vec<T::AccountId> = <CandidateList<T>>::get()
 			.iter()

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs

@@ -62,7 +62,7 @@ use frame_support::{
 		ConstU128, ConstU32, ConstU64, ConstU8, EitherOfDiverse, Equals, InstanceFilter,
 		TransformOrigin,
 	},
-	weights::{constants::WEIGHT_REF_TIME_PER_SECOND, ConstantMultiplier, Weight},
+	weights::{ConstantMultiplier, Weight},
 	BoundedVec, PalletId,
 };
 use frame_system::{
@@ -75,11 +75,10 @@ use parachains_common::{
 	impls::DealWithFees,
 	message_queue::{NarrowOriginToSibling, ParaIdToSibling},
 	AccountId, AssetIdForTrustBackedAssets, AuraId, Balance, BlockNumber, CollectionId, Hash,
-	Header, ItemId, Nonce, Signature, AVERAGE_ON_INITIALIZE_RATIO, DAYS, HOURS,
-	NORMAL_DISPATCH_RATIO,
+	Header, ItemId, Nonce, Signature, AVERAGE_ON_INITIALIZE_RATIO, NORMAL_DISPATCH_RATIO,
 };
 use sp_runtime::{Perbill, RuntimeDebug};
-use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee};
+use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee, time::*};
 use xcm_config::{
 	ForeignAssetsConvertedConcreteId, ForeignCreatorsSovereignAccountOf, GovernanceLocation,
 	PoolAssetsConvertedConcreteId, TokenLocation, TokenLocationV3,
@@ -140,28 +139,6 @@ pub fn native_version() -> NativeVersion {
 	NativeVersion { runtime_version: VERSION, can_author_with: Default::default() }
 }
 
-/// We allow for 2 seconds of compute with a 6 second average block.
-const MAXIMUM_BLOCK_WEIGHT: Weight = Weight::from_parts(
-	WEIGHT_REF_TIME_PER_SECOND.saturating_mul(2),
-	cumulus_primitives_core::relay_chain::MAX_POV_SIZE as u64,
-);
-
-/// Maximum number of blocks simultaneously accepted by the Runtime, not yet included
-/// into the relay chain.
-const UNINCLUDED_SEGMENT_CAPACITY: u32 = 3;
-/// How many parachain blocks are processed by the relay chain per parent. Limits the
-/// number of blocks authored per slot.
-const BLOCK_PROCESSING_VELOCITY: u32 = 1;
-
-/// This determines the average expected block time that we are targeting.
-/// Blocks will be produced at a minimum duration defined by `SLOT_DURATION`.
-/// `SLOT_DURATION` is picked up by `pallet_timestamp` which is in turn picked
-/// up by `pallet_aura` to implement `fn slot_duration()`.
-///
-/// Change this to adjust the block time.
-pub const MILLISECS_PER_BLOCK: u64 = 6000;
-pub const SLOT_DURATION: u64 = MILLISECS_PER_BLOCK;
-
 parameter_types! {
 	pub const Version: RuntimeVersion = VERSION;
 	pub RuntimeBlockLength: BlockLength =

cumulus/parachains/runtimes/assets/asset-hub-rococo/tests/tests.rs

@@ -28,7 +28,7 @@ use asset_hub_rococo_runtime::{
 	AllPalletsWithoutSystem, AssetConversion, AssetDeposit, Assets, Balances, CollatorSelection,
 	ExistentialDeposit, ForeignAssets, ForeignAssetsInstance, MetadataDepositBase,
 	MetadataDepositPerByte, ParachainSystem, Runtime, RuntimeCall, RuntimeEvent, SessionKeys,
-	ToWestendXcmRouterInstance, TrustBackedAssetsInstance, XcmpQueue, SLOT_DURATION,
+	ToWestendXcmRouterInstance, TrustBackedAssetsInstance, XcmpQueue,
 };
 use asset_test_utils::{
 	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys,
@@ -50,9 +50,7 @@ use parachains_common::{AccountId, AssetIdForTrustBackedAssets, AuraId, Balance}
 use sp_consensus_aura::SlotDuration;
 use sp_runtime::traits::MaybeEquivalence;
 use std::convert::Into;
-use testnet_parachains_constants::rococo::{
-	consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, currency::UNITS, fee::WeightToFee,
-};
+use testnet_parachains_constants::rococo::{consensus::*, currency::UNITS, fee::WeightToFee};
 use xcm::latest::prelude::{Assets as XcmAssets, *};
 use xcm_builder::V4V3LocationConverter;
 use xcm_executor::traits::{JustTry, WeightTrader};

cumulus/parachains/runtimes/assets/asset-hub-westend/Cargo.toml

@@ -73,6 +73,7 @@ cumulus-pallet-parachain-system = { path = "../../../../pallets/parachain-system
 cumulus-pallet-session-benchmarking = { path = "../../../../pallets/session-benchmarking", default-features = false }
 cumulus-pallet-xcm = { path = "../../../../pallets/xcm", default-features = false }
 cumulus-pallet-xcmp-queue = { path = "../../../../pallets/xcmp-queue", default-features = false, features = ["bridging"] }
+cumulus-primitives-aura = { path = "../../../../primitives/aura", default-features = false }
 cumulus-primitives-core = { path = "../../../../primitives/core", default-features = false }
 cumulus-primitives-utility = { path = "../../../../primitives/utility", default-features = false }
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
@@ -175,6 +176,7 @@ std = [
 	"cumulus-pallet-session-benchmarking/std",
 	"cumulus-pallet-xcm/std",
 	"cumulus-pallet-xcmp-queue/std",
+	"cumulus-primitives-aura/std",
 	"cumulus-primitives-core/std",
 	"cumulus-primitives-utility/std",
 	"frame-benchmarking?/std",

cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs

@@ -32,7 +32,7 @@ use assets_common::{
 	AssetIdForTrustBackedAssetsConvert,
 };
 use codec::{Decode, Encode, MaxEncodedLen};
-use cumulus_pallet_parachain_system::RelayNumberStrictlyIncreases;
+use cumulus_pallet_parachain_system::RelayNumberMonotonicallyIncreases;
 use cumulus_primitives_core::{AggregateMessageOrigin, ParaId};
 use frame_support::{
 	construct_runtime, derive_impl,
@@ -58,7 +58,7 @@ use pallet_xcm::EnsureXcm;
 use parachains_common::{
 	impls::DealWithFees, message_queue::*, AccountId, AssetIdForTrustBackedAssets, AuraId, Balance,
 	BlockNumber, CollectionId, Hash, Header, ItemId, Nonce, Signature, AVERAGE_ON_INITIALIZE_RATIO,
-	DAYS, HOURS, MAXIMUM_BLOCK_WEIGHT, NORMAL_DISPATCH_RATIO, SLOT_DURATION,
+	NORMAL_DISPATCH_RATIO,
 };
 use sp_api::impl_runtime_apis;
 use sp_core::{crypto::KeyTypeId, OpaqueMetadata};
@@ -72,7 +72,7 @@ use sp_std::prelude::*;
 #[cfg(feature = "std")]
 use sp_version::NativeVersion;
 use sp_version::RuntimeVersion;
-use testnet_parachains_constants::westend::{consensus::*, currency::*, fee::WeightToFee};
+use testnet_parachains_constants::westend::{consensus::*, currency::*, fee::WeightToFee, time::*};
 use xcm_config::{
 	ForeignAssetsConvertedConcreteId, PoolAssetsConvertedConcreteId,
 	TrustBackedAssetsConvertedConcreteId, TrustBackedAssetsPalletLocationV3, WestendLocation,
@@ -171,6 +171,9 @@ impl pallet_timestamp::Config for Runtime {
 	/// A timestamp: milliseconds since the unix epoch.
 	type Moment = u64;
 	type OnTimestampSet = Aura;
+	#[cfg(feature = "experimental")]
+	type MinimumPeriod = ConstU64<0>;
+	#[cfg(not(feature = "experimental"))]
 	type MinimumPeriod = ConstU64<{ SLOT_DURATION / 2 }>;
 	type WeightInfo = weights::pallet_timestamp::WeightInfo<Runtime>;
 }
@@ -604,15 +607,17 @@ impl cumulus_pallet_parachain_system::Config for Runtime {
 	type OutboundXcmpMessageSource = XcmpQueue;
 	type XcmpMessageHandler = XcmpQueue;
 	type ReservedXcmpWeight = ReservedXcmpWeight;
-	type CheckAssociatedRelayNumber = RelayNumberStrictlyIncreases;
-	type ConsensusHook = cumulus_pallet_aura_ext::FixedVelocityConsensusHook<
-		Runtime,
-		RELAY_CHAIN_SLOT_DURATION_MILLIS,
-		BLOCK_PROCESSING_VELOCITY,
-		UNINCLUDED_SEGMENT_CAPACITY,
-	>;
+	type CheckAssociatedRelayNumber = RelayNumberMonotonicallyIncreases;
+	type ConsensusHook = ConsensusHook;
 }
 
+type ConsensusHook = cumulus_pallet_aura_ext::FixedVelocityConsensusHook<
+	Runtime,
+	RELAY_CHAIN_SLOT_DURATION_MILLIS,
+	BLOCK_PROCESSING_VELOCITY,
+	UNINCLUDED_SEGMENT_CAPACITY,
+>;
+
 impl parachain_info::Config for Runtime {}
 
 parameter_types! {
@@ -697,9 +702,9 @@ impl pallet_aura::Config for Runtime {
 	type AuthorityId = AuraId;
 	type DisabledValidators = ();
 	type MaxAuthorities = ConstU32<100_000>;
-	type AllowMultipleBlocksPerSlot = ConstBool<false>;
+	type AllowMultipleBlocksPerSlot = ConstBool<true>;
 	#[cfg(feature = "experimental")]
-	type SlotDuration = pallet_aura::MinimumPeriodTimesTwo<Self>;
+	type SlotDuration = ConstU64<SLOT_DURATION>;
 }
 
 parameter_types! {
@@ -980,7 +985,7 @@ impl frame_support::traits::OnRuntimeUpgrade for DeleteUndecodableStorage {
 			},
 			Err(e) => {
 				log::error!("Failed to destroy undecodable NFT item: {:?}", e);
-				return <Runtime as frame_system::Config>::DbWeight::get().reads_writes(0, writes)
+				return <Runtime as frame_system::Config>::DbWeight::get().reads_writes(0, writes);
 			},
 		}
 
@@ -992,7 +997,7 @@ impl frame_support::traits::OnRuntimeUpgrade for DeleteUndecodableStorage {
 			},
 			Err(e) => {
 				log::error!("Failed to destroy undecodable NFT item: {:?}", e);
-				return <Runtime as frame_system::Config>::DbWeight::get().reads_writes(0, writes)
+				return <Runtime as frame_system::Config>::DbWeight::get().reads_writes(0, writes);
 			},
 		}
 
@@ -1090,14 +1095,23 @@ mod benches {
 impl_runtime_apis! {
 	impl sp_consensus_aura::AuraApi<Block, AuraId> for Runtime {
 		fn slot_duration() -> sp_consensus_aura::SlotDuration {
-			sp_consensus_aura::SlotDuration::from_millis(Aura::slot_duration())
+			sp_consensus_aura::SlotDuration::from_millis(SLOT_DURATION)
 		}
 
 		fn authorities() -> Vec<AuraId> {
 			Aura::authorities().into_inner()
 		}
 	}
 
+	impl cumulus_primitives_aura::AuraUnincludedSegmentApi<Block> for Runtime {
+		fn can_build_upon(
+			included_hash: <Block as BlockT>::Hash,
+			slot: cumulus_primitives_aura::Slot,
+		) -> bool {
+			ConsensusHook::can_build_upon(included_hash, slot)
+		}
+	}
+
 	impl sp_api::Core<Block> for Runtime {
 		fn version() -> RuntimeVersion {
 			VERSION

cumulus/parachains/runtimes/assets/asset-hub-westend/tests/tests.rs

@@ -47,13 +47,11 @@ use frame_support::{
 	},
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
-use parachains_common::{AccountId, AssetIdForTrustBackedAssets, AuraId, Balance, SLOT_DURATION};
+use parachains_common::{AccountId, AssetIdForTrustBackedAssets, AuraId, Balance};
 use sp_consensus_aura::SlotDuration;
 use sp_runtime::traits::MaybeEquivalence;
 use std::convert::Into;
-use testnet_parachains_constants::westend::{
-	consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, currency::UNITS, fee::WeightToFee,
-};
+use testnet_parachains_constants::westend::{consensus::*, currency::UNITS, fee::WeightToFee};
 use xcm::latest::prelude::{Assets as XcmAssets, *};
 use xcm_builder::V4V3LocationConverter;
 use xcm_executor::traits::{JustTry, WeightTrader};

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/Cargo.toml

@@ -76,6 +76,7 @@ cumulus-pallet-xcm = { path = "../../../../pallets/xcm", default-features = fals
 cumulus-pallet-xcmp-queue = { path = "../../../../pallets/xcmp-queue", default-features = false, features = [
 	"bridging",
 ] }
+cumulus-primitives-aura = { path = "../../../../primitives/aura", default-features = false }
 cumulus-primitives-core = { path = "../../../../primitives/core", default-features = false }
 cumulus-primitives-utility = { path = "../../../../primitives/utility", default-features = false }
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
@@ -153,6 +154,7 @@ std = [
 	"cumulus-pallet-session-benchmarking/std",
 	"cumulus-pallet-xcm/std",
 	"cumulus-pallet-xcmp-queue/std",
+	"cumulus-primitives-aura/std",
 	"cumulus-primitives-core/std",
 	"cumulus-primitives-utility/std",
 	"frame-benchmarking/std",

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/bridge_to_westend_config.rs

@@ -299,7 +299,7 @@ mod tests {
 		>(AssertCompleteBridgeConstants {
 			this_chain_constants: AssertChainConstants {
 				block_length: bp_bridge_hub_rococo::BlockLength::get(),
-				block_weights: bp_bridge_hub_rococo::BlockWeights::get(),
+				block_weights: bp_bridge_hub_rococo::BlockWeightsForAsyncBacking::get(),
 			},
 			messages_pallet_constants: AssertBridgeMessagesPalletConstants {
 				max_unrewarded_relayers_in_bridged_confirmation_tx: