Remove AssignmentProviderConfig and use parameters from `HostConfig…

…uration` instead (#3181)

This PR removes `AssignmentProviderConfig` and uses the corresponding
ondemand parameters from `HostConfiguration` instead. Additionally
`scheduling_lookahead` and all coretime/ondemand related parameters are
extracted in a separate struct - `SchedulerParams`.

The most relevant commit from the PR is [this
one](830bc0f).

Fixes #2268

---------

Co-authored-by: command-bot <>

cumulus/zombienet/tests/0002-pov_recovery.toml

@@ -4,7 +4,7 @@ default_command = "polkadot"
 
 chain = "rococo-local"
 
-[relaychain.genesis.runtimeGenesis.patch.configuration.config]
+[relaychain.genesis.runtimeGenesis.patch.configuration.config.scheduler_params]
 # set parameters such that collators only connect to 1 validator as a backing group
 max_validators_per_core = 1
 group_rotation_frequency = 100 # 10 mins

polkadot/node/service/src/chain_spec.rs

@@ -24,6 +24,8 @@ use polkadot_primitives::{AccountId, AccountPublic, AssignmentId, ValidatorId};
 use sp_authority_discovery::AuthorityId as AuthorityDiscoveryId;
 use sp_consensus_babe::AuthorityId as BabeId;
 
+#[cfg(any(feature = "rococo-native", feature = "westend-native",))]
+use polkadot_primitives::vstaging::SchedulerParams;
 #[cfg(feature = "rococo-native")]
 use rococo_runtime as rococo;
 #[cfg(feature = "rococo-native")]
@@ -129,8 +131,6 @@ fn default_parachains_host_configuration(
 		max_code_size: MAX_CODE_SIZE,
 		max_pov_size: MAX_POV_SIZE,
 		max_head_data_size: 32 * 1024,
-		group_rotation_frequency: 20,
-		paras_availability_period: 4,
 		max_upward_queue_count: 8,
 		max_upward_queue_size: 1024 * 1024,
 		max_downward_message_size: 1024 * 1024,
@@ -151,11 +151,16 @@ fn default_parachains_host_configuration(
 		relay_vrf_modulo_samples: 2,
 		zeroth_delay_tranche_width: 0,
 		minimum_validation_upgrade_delay: 5,
-		scheduling_lookahead: 2,
 		async_backing_params: AsyncBackingParams {
 			max_candidate_depth: 3,
 			allowed_ancestry_len: 2,
 		},
+		scheduler_params: SchedulerParams {
+			lookahead: 2,
+			group_rotation_frequency: 20,
+			paras_availability_period: 4,
+			..Default::default()
+		},
 		..Default::default()
 	}
 }
@@ -891,7 +896,10 @@ pub fn rococo_testnet_genesis(
 		"sudo": { "key": Some(root_key.clone()) },
 		"configuration": {
 			"config": polkadot_runtime_parachains::configuration::HostConfiguration {
-				max_validators_per_core: Some(1),
+				scheduler_params: SchedulerParams {
+					max_validators_per_core: Some(1),
+					..default_parachains_host_configuration().scheduler_params
+				},
 				..default_parachains_host_configuration()
 			},
 		},

polkadot/node/test/service/src/chain_spec.rs

@@ -19,7 +19,9 @@
 use babe_primitives::AuthorityId as BabeId;
 use grandpa::AuthorityId as GrandpaId;
 use pallet_staking::Forcing;
-use polkadot_primitives::{AccountId, AssignmentId, ValidatorId, MAX_CODE_SIZE, MAX_POV_SIZE};
+use polkadot_primitives::{
+	vstaging::SchedulerParams, AccountId, AssignmentId, ValidatorId, MAX_CODE_SIZE, MAX_POV_SIZE,
+};
 use polkadot_service::chain_spec::{get_account_id_from_seed, get_from_seed, Extensions};
 use polkadot_test_runtime::BABE_GENESIS_EPOCH_CONFIG;
 use sc_chain_spec::{ChainSpec, ChainType};
@@ -165,11 +167,14 @@ fn polkadot_testnet_genesis(
 				max_code_size: MAX_CODE_SIZE,
 				max_pov_size: MAX_POV_SIZE,
 				max_head_data_size: 32 * 1024,
-				group_rotation_frequency: 20,
-				paras_availability_period: 4,
 				no_show_slots: 10,
 				minimum_validation_upgrade_delay: 5,
 				max_downward_message_size: 1024,
+				scheduler_params: SchedulerParams {
+					group_rotation_frequency: 20,
+					paras_availability_period: 4,
+					..Default::default()
+				},
 				..Default::default()
 			},
 		}

polkadot/primitives/src/vstaging/mod.rs

@@ -23,6 +23,7 @@ use sp_std::prelude::*;
 use parity_scale_codec::{Decode, Encode};
 use primitives::RuntimeDebug;
 use scale_info::TypeInfo;
+use sp_arithmetic::Perbill;
 
 /// Approval voting configuration parameters
 #[derive(
@@ -50,6 +51,81 @@ impl Default for ApprovalVotingParams {
 	}
 }
 
+/// Scheduler configuration parameters. All coretime/ondemand parameters are here.
+#[derive(
+	RuntimeDebug,
+	Copy,
+	Clone,
+	PartialEq,
+	Encode,
+	Decode,
+	TypeInfo,
+	serde::Serialize,
+	serde::Deserialize,
+)]
+pub struct SchedulerParams<BlockNumber> {
+	/// How often parachain groups should be rotated across parachains.
+	///
+	/// Must be non-zero.
+	pub group_rotation_frequency: BlockNumber,
+	/// Availability timeout for a block on a core, measured in blocks.
+	///
+	/// This is the maximum amount of blocks after a core became occupied that validators have time
+	/// to make the block available.
+	///
+	/// This value only has effect on group rotations. If backers backed something at the end of
+	/// their rotation, the occupied core affects the backing group that comes afterwards. We limit
+	/// the effect one backing group can have on the next to `paras_availability_period` blocks.
+	///
+	/// Within a group rotation there is no timeout as backers are only affecting themselves.
+	///
+	/// Must be at least 1. With a value of 1, the previous group will not be able to negatively
+	/// affect the following group at the expense of a tight availability timeline at group
+	/// rotation boundaries.
+	pub paras_availability_period: BlockNumber,
+	/// The maximum number of validators to have per core.
+	///
+	/// `None` means no maximum.
+	pub max_validators_per_core: Option<u32>,
+	/// The amount of blocks ahead to schedule paras.
+	pub lookahead: u32,
+	/// How many cores are managed by the coretime chain.
+	pub num_cores: u32,
+	/// The max number of times a claim can time out in availability.
+	pub max_availability_timeouts: u32,
+	/// The maximum queue size of the pay as you go module.
+	pub on_demand_queue_max_size: u32,
+	/// The target utilization of the spot price queue in percentages.
+	pub on_demand_target_queue_utilization: Perbill,
+	/// How quickly the fee rises in reaction to increased utilization.
+	/// The lower the number the slower the increase.
+	pub on_demand_fee_variability: Perbill,
+	/// The minimum amount needed to claim a slot in the spot # queue.
+	pub on_demand_base_fee: Balance,
+	/// The number of blocks a claim stays in the scheduler's claimqueue before getting cleared.
+	/// This number should go reasonably higher than the number of blocks in the async backing
+	/// lookahead.
+	pub ttl: BlockNumber,
+}
+
+impl<BlockNumber: Default + From<u32>> Default for SchedulerParams<BlockNumber> {
+	fn default() -> Self {
+		Self {
+			group_rotation_frequency: 1u32.into(),
+			paras_availability_period: 1u32.into(),
+			max_validators_per_core: Default::default(),
+			lookahead: 1,
+			num_cores: Default::default(),
+			max_availability_timeouts: Default::default(),
+			on_demand_queue_max_size: ON_DEMAND_DEFAULT_QUEUE_MAX_SIZE,
+			on_demand_target_queue_utilization: Perbill::from_percent(25),
+			on_demand_fee_variability: Perbill::from_percent(3),
+			on_demand_base_fee: 10_000_000u128,
+			ttl: 5u32.into(),
+		}
+	}
+}
+
 use bitvec::vec::BitVec;
 
 /// Bit indices in the `HostConfiguration.node_features` that correspond to different node features.

polkadot/roadmap/implementers-guide/src/types/runtime.md

@@ -4,106 +4,24 @@ Types used within the runtime exclusively and pervasively.
 
 ## Host Configuration
 
-The internal-to-runtime configuration of the parachain host. This is expected to be altered only by governance procedures.
-
-```rust
-struct HostConfiguration {
-	/// The minimum period, in blocks, between which parachains can update their validation code.
-	pub validation_upgrade_cooldown: BlockNumber,
-	/// The delay, in blocks, before a validation upgrade is applied.
-	pub validation_upgrade_delay: BlockNumber,
-	/// How long to keep code on-chain, in blocks. This should be sufficiently long that disputes
-	/// have concluded.
-	pub code_retention_period: BlockNumber,
-	/// The maximum validation code size, in bytes.
-	pub max_code_size: u32,
-	/// The maximum head-data size, in bytes.
-	pub max_head_data_size: u32,
-	/// The amount of availability cores to dedicate to parathreads (on-demand parachains).
-	pub parathread_cores: u32,
-	/// The number of retries that a parathread (on-demand parachain) author has to submit their block.
-	pub parathread_retries: u32,
-	/// How often parachain groups should be rotated across parachains.
-	pub group_rotation_frequency: BlockNumber,
-	/// The availability period, in blocks, for parachains. This is the amount of blocks
-	/// after inclusion that validators have to make the block available and signal its availability to
-	/// the chain. Must be at least 1.
-	pub chain_availability_period: BlockNumber,
-	/// The availability period, in blocks, for parathreads (on-demand parachains). Same as the `chain_availability_period`,
-	/// but a differing timeout due to differing requirements. Must be at least 1.
-	pub thread_availability_period: BlockNumber,
-	/// The amount of blocks ahead to schedule on-demand parachains.
-	pub scheduling_lookahead: u32,
-	/// The maximum number of validators to have per core. `None` means no maximum.
-	pub max_validators_per_core: Option<u32>,
-	/// The maximum number of validators to use for parachains, in total. `None` means no maximum.
-	pub max_validators: Option<u32>,
-	/// The amount of sessions to keep for disputes.
-	pub dispute_period: SessionIndex,
-	/// How long after dispute conclusion to accept statements.
-	pub dispute_post_conclusion_acceptance_period: BlockNumber,
-	/// The maximum number of dispute spam slots
-	pub dispute_max_spam_slots: u32,
-	/// The amount of consensus slots that must pass between submitting an assignment and
-	/// submitting an approval vote before a validator is considered a no-show.
-	/// Must be at least 1.
-	pub no_show_slots: u32,
-	/// The number of delay tranches in total.
-	pub n_delay_tranches: u32,
-	/// The width of the zeroth delay tranche for approval assignments. This many delay tranches
-	/// beyond 0 are all consolidated to form a wide 0 tranche.
-	pub zeroth_delay_tranche_width: u32,
-	/// The number of validators needed to approve a block.
-	pub needed_approvals: u32,
-	/// The number of samples to use in `RelayVRFModulo` or `RelayVRFModuloCompact` approval assignment criterions.
-	pub relay_vrf_modulo_samples: u32,
-	/// Total number of individual messages allowed in the parachain -> relay-chain message queue.
-	pub max_upward_queue_count: u32,
-	/// Total size of messages allowed in the parachain -> relay-chain message queue before which
-	/// no further messages may be added to it. If it exceeds this then the queue may contain only
-	/// a single message.
-	pub max_upward_queue_size: u32,
-	/// The maximum size of an upward message that can be sent by a candidate.
-	///
-	/// This parameter affects the upper bound of size of `CandidateCommitments`.
-	pub max_upward_message_size: u32,
-	/// The maximum number of messages that a candidate can contain.
-	///
-	/// This parameter affects the upper bound of size of `CandidateCommitments`.
-	pub max_upward_message_num_per_candidate: u32,
-	/// The maximum size of a message that can be put in a downward message queue.
-	///
-	/// Since we require receiving at least one DMP message the obvious upper bound of the size is
-	/// the PoV size. Of course, there is a lot of other different things that a parachain may
-	/// decide to do with its PoV so this value in practice will be picked as a fraction of the PoV
-	/// size.
-	pub max_downward_message_size: u32,
-	/// The deposit that the sender should provide for opening an HRMP channel.
-	pub hrmp_sender_deposit: u32,
-	/// The deposit that the recipient should provide for accepting opening an HRMP channel.
-	pub hrmp_recipient_deposit: u32,
-	/// The maximum number of messages allowed in an HRMP channel at once.
-	pub hrmp_channel_max_capacity: u32,
-	/// The maximum total size of messages in bytes allowed in an HRMP channel at once.
-	pub hrmp_channel_max_total_size: u32,
-	/// The maximum number of inbound HRMP channels a parachain is allowed to accept.
-	pub hrmp_max_parachain_inbound_channels: u32,
-	/// The maximum number of inbound HRMP channels a parathread (on-demand parachain) is allowed to accept.
-	pub hrmp_max_parathread_inbound_channels: u32,
-	/// The maximum size of a message that could ever be put into an HRMP channel.
-	///
-	/// This parameter affects the upper bound of size of `CandidateCommitments`.
-	pub hrmp_channel_max_message_size: u32,
-	/// The maximum number of outbound HRMP channels a parachain is allowed to open.
-	pub hrmp_max_parachain_outbound_channels: u32,
-	/// The maximum number of outbound HRMP channels a parathread (on-demand parachain) is allowed to open.
-	pub hrmp_max_parathread_outbound_channels: u32,
-	/// The maximum number of outbound HRMP messages can be sent by a candidate.
-	///
-	/// This parameter affects the upper bound of size of `CandidateCommitments`.
-	pub hrmp_max_message_num_per_candidate: u32,
-}
-```
+The internal-to-runtime configuration of the parachain host is kept in `struct HostConfiguration`. This is expected to
+be altered only by governance procedures or via migrations from the Polkadot-SDK codebase. The latest definition of
+`HostConfiguration` can be found in the project repo
+[here](https://github.com/paritytech/polkadot-sdk/blob/master/polkadot/runtime/parachains/src/configuration.rs). Each
+parameter has got a doc comment so for any details please refer to the code.
+
+Some related parameters in `HostConfiguration` are grouped together so that they can be managed easily. These are:
+* `async_backing_params` in `struct AsyncBackingParams`
+* `executor_params` in `struct ExecutorParams`
+* `approval_voting_params` in `struct ApprovalVotingParams`
+* `scheduler_params` in `struct SchedulerParams`
+
+Check the definitions of these structs for further details.
+
+### Configuration migrations
+Modifying `HostConfiguration` requires a storage migration. These migrations are located in the
+[`migrations`](https://github.com/paritytech/polkadot-sdk/blob/master/polkadot/runtime/parachains/src/configuration.rs)
+subfolder of Polkadot-SDK repo.
 
 ## ParaInherentData
 

polkadot/runtime/parachains/src/assigner_coretime/mock_helpers.rs

@@ -64,11 +64,12 @@ impl GenesisConfigBuilder {
 	pub(super) fn build(self) -> MockGenesisConfig {
 		let mut genesis = default_genesis_config();
 		let config = &mut genesis.configuration.config;
-		config.coretime_cores = self.on_demand_cores;
-		config.on_demand_base_fee = self.on_demand_base_fee;
-		config.on_demand_fee_variability = self.on_demand_fee_variability;
-		config.on_demand_queue_max_size = self.on_demand_max_queue_size;
-		config.on_demand_target_queue_utilization = self.on_demand_target_queue_utilization;
+		config.scheduler_params.num_cores = self.on_demand_cores;
+		config.scheduler_params.on_demand_base_fee = self.on_demand_base_fee;
+		config.scheduler_params.on_demand_fee_variability = self.on_demand_fee_variability;
+		config.scheduler_params.on_demand_queue_max_size = self.on_demand_max_queue_size;
+		config.scheduler_params.on_demand_target_queue_utilization =
+			self.on_demand_target_queue_utilization;
 
 		let paras = &mut genesis.paras.paras;
 		for para_id in self.onboarded_on_demand_chains {

polkadot/runtime/parachains/src/assigner_coretime/mod.rs

@@ -30,7 +30,7 @@ mod tests;
 use crate::{
 	assigner_on_demand, configuration,
 	paras::AssignCoretime,
-	scheduler::common::{Assignment, AssignmentProvider, AssignmentProviderConfig},
+	scheduler::common::{Assignment, AssignmentProvider},
 	ParaId,
 };
 
@@ -316,14 +316,6 @@ impl<T: Config> AssignmentProvider<BlockNumberFor<T>> for Pallet<T> {
 		}
 	}
 
-	fn get_provider_config(_core_idx: CoreIndex) -> AssignmentProviderConfig<BlockNumberFor<T>> {
-		let config = <configuration::Pallet<T>>::config();
-		AssignmentProviderConfig {
-			max_availability_timeouts: config.on_demand_retries,
-			ttl: config.on_demand_ttl,
-		}
-	}
-
 	#[cfg(any(feature = "runtime-benchmarks", test))]
 	fn get_mock_assignment(_: CoreIndex, para_id: primitives::Id) -> Assignment {
 		// Given that we are not tracking anything in `Bulk` assignments, it is safe to always
@@ -333,7 +325,7 @@ impl<T: Config> AssignmentProvider<BlockNumberFor<T>> for Pallet<T> {
 
 	fn session_core_count() -> u32 {
 		let config = <configuration::Pallet<T>>::config();
-		config.coretime_cores
+		config.scheduler_params.num_cores
 	}
 }
 
@@ -482,8 +474,8 @@ impl<T: Config> AssignCoretime for Pallet<T> {
 
 		// Add a new core and assign the para to it.
 		let mut config = <configuration::Pallet<T>>::config();
-		let core = config.coretime_cores;
-		config.coretime_cores.saturating_inc();
+		let core = config.scheduler_params.num_cores;
+		config.scheduler_params.num_cores.saturating_inc();
 
 		// `assign_coretime` is only called at genesis or by root, so setting the active
 		// config here is fine.

polkadot/runtime/parachains/src/assigner_on_demand/benchmarking.rs

@@ -43,7 +43,7 @@ where
 {
 	ParasShared::<T>::set_session_index(SESSION_INDEX);
 	let mut config = HostConfiguration::default();
-	config.coretime_cores = 1;
+	config.scheduler_params.num_cores = 1;
 	ConfigurationPallet::<T>::force_set_active_config(config);
 	let mut parachains = ParachainsCache::new();
 	ParasPallet::<T>::initialize_para_now(

polkadot/runtime/parachains/src/assigner_on_demand/mock_helpers.rs

@@ -63,11 +63,12 @@ impl GenesisConfigBuilder {
 	pub(super) fn build(self) -> MockGenesisConfig {
 		let mut genesis = default_genesis_config();
 		let config = &mut genesis.configuration.config;
-		config.coretime_cores = self.on_demand_cores;
-		config.on_demand_base_fee = self.on_demand_base_fee;
-		config.on_demand_fee_variability = self.on_demand_fee_variability;
-		config.on_demand_queue_max_size = self.on_demand_max_queue_size;
-		config.on_demand_target_queue_utilization = self.on_demand_target_queue_utilization;
+		config.scheduler_params.num_cores = self.on_demand_cores;
+		config.scheduler_params.on_demand_base_fee = self.on_demand_base_fee;
+		config.scheduler_params.on_demand_fee_variability = self.on_demand_fee_variability;
+		config.scheduler_params.on_demand_queue_max_size = self.on_demand_max_queue_size;
+		config.scheduler_params.on_demand_target_queue_utilization =
+			self.on_demand_target_queue_utilization;
 
 		let paras = &mut genesis.paras.paras;
 		for para_id in self.onboarded_on_demand_chains {