ISMP Parachain Inherent Provider
This module leverages the ProvideInherent functionality to submit consensus update messages. This approach offers a significant advantage:
- Eliminating Off-chain Consensus Relayer : By utilizing inherent messages for receiving consensus messages about finalized parachain block headers, the need for a separate off-chain consensus relayer is eliminated.
- Simplified Architecture : This reduces the overall system complexity by removing an external component (the off-chain consensus relayer).
- Improved Efficiency : Inherents are a built-in mechanism within the polkadot-sdk, allowing the collator to act as the consensus relayer.
The inherent provider module needs to be added to the collator's client subsystems as shown in the code below
fn start_consensus(
client: Arc<FullClient>,
backend: Arc<FullBackend>,
block_import: ParachainBlockImport,
prometheus_registry: Option<&Registry>,
telemetry: Option<TelemetryHandle>,
task_manager: &TaskManager,
relay_chain_interface: Arc<dyn RelayChainInterface>,
transaction_pool: Arc<sc_transaction_pool::FullPool<opaque::Block, FullClient>>,
sync_oracle: Arc<SyncingService<opaque::Block>>,
keystore: KeystorePtr,
relay_chain_slot_duration: Duration,
para_id: ParaId,
collator_key: CollatorPair,
overseer_handle: OverseerHandle,
announce_block: Arc<dyn Fn(opaque::Hash, Option<Vec<u8>>) + Send + Sync>,
) {
// .. omitted calls
let (client_clone, relay_chain_interface_clone) =
(client.clone(), relay_chain_interface.clone());
let params = lookahead::Params {
create_inherent_data_providers: move |parent, ()| {
let client = client_clone.clone();
let relay_chain_interface = relay_chain_interface_clone.clone();
async move {
let inherent = ismp_parachain_inherent::ConsensusInherentProvider::create(
parent,
client,
relay_chain_interface,
).await?;
Ok(inherent)
}
},
..Default::default()
// omitted fields
};
// ..omitted calls
}