network/kad: Increase memory store capacity for providers

prdoc/pr_9315.prdoc

@@ -0,0 +1,15 @@
+title: 'network/kad: Increase memory store capacity for providers'
+doc:
+- audience: Node Dev
+  description: |-
+    Increase Kademlia memory store capacity for DHT content providers (used by parachain DHT-based bootnodes) and reduce provider republish interval & TTL. This is needed to support testnets with 1-minute fast runtime and up to 13 parachains.
+
+    Parameters set:
+    - 10000 provider keys per node
+    - 10h provider record TTL
+    - 3.5h provider republish interval
+
+    Closes https://github.com/paritytech/litep2p/issues/405.
+crates:
+- name: sc-network
+  bump: minor

substrate/client/network/src/config.rs

@@ -74,6 +74,21 @@ use std::{
 /// are possible in custom nodes through [`NetworkConfiguration`].
 pub const DEFAULT_IDLE_CONNECTION_TIMEOUT: Duration = Duration::from_secs(10);
 
+/// Maximum number of locally kept Kademlia provider keys.
+///
+/// 10000 keys is enough for a testnet with fast runtime (1-minute epoch) and 13 parachains.
+pub const KADEMLIA_MAX_PROVIDER_KEYS: usize = 10000;
+
+/// Time to keep Kademlia content provider records.
+///
+/// 10 h is enough time to keep the parachain bootnode record for two 4-hour epochs.
+pub const KADEMLIA_PROVIDER_RECORD_TTL: Duration = Duration::from_secs(10 * 3600);
+
+/// Interval of republishing Kademlia provider records.
+///
+/// 3.5 h means we refresh next epoch provider record 30 minutes before next 4-hour epoch comes.
+pub const KADEMLIA_PROVIDER_REPUBLISH_INTERVAL: Duration = Duration::from_secs(12600);
+
 /// Protocol name prefix, transmitted on the wire for legacy protocol names.
 /// I.e., `dot` in `/dot/sync/2`. Should be unique for each chain. Always UTF-8.
 /// Deprecated in favour of genesis hash & fork ID based protocol names.

substrate/client/network/src/discovery.rs

@@ -46,7 +46,13 @@
 //! active mechanism that asks nodes for the addresses they are listening on. Whenever we learn
 //! of a node's address, you must call `add_self_reported_address`.
 
-use crate::{config::ProtocolId, utils::LruHashSet};
+use crate::{
+	config::{
+		ProtocolId, KADEMLIA_MAX_PROVIDER_KEYS, KADEMLIA_PROVIDER_RECORD_TTL,
+		KADEMLIA_PROVIDER_REPUBLISH_INTERVAL,
+	},
+	utils::LruHashSet,
+};
 
 use array_bytes::bytes2hex;
 use futures::prelude::*;
@@ -56,7 +62,7 @@ use libp2p::{
 	core::{transport::PortUse, Endpoint, Multiaddr},
 	kad::{
 		self,
-		store::{MemoryStore, RecordStore},
+		store::{MemoryStore, MemoryStoreConfig, RecordStore},
 		Behaviour as Kademlia, BucketInserts, Config as KademliaConfig, Event as KademliaEvent,
 		Event, GetClosestPeersError, GetClosestPeersOk, GetProvidersError, GetProvidersOk,
 		GetRecordOk, PeerRecord, QueryId, QueryResult, Quorum, Record, RecordKey,
@@ -239,7 +245,18 @@ impl DiscoveryConfig {
 			// auto-insertion and instead add peers manually.
 			config.set_kbucket_inserts(BucketInserts::Manual);
 			config.disjoint_query_paths(kademlia_disjoint_query_paths);
-			let store = MemoryStore::new(local_peer_id);
+
+			config.set_provider_record_ttl(Some(KADEMLIA_PROVIDER_RECORD_TTL));
+			config.set_provider_publication_interval(Some(KADEMLIA_PROVIDER_REPUBLISH_INTERVAL));
+
+			let store = MemoryStore::with_config(
+				local_peer_id,
+				MemoryStoreConfig {
+					max_provided_keys: KADEMLIA_MAX_PROVIDER_KEYS,
+					..Default::default()
+				},
+			);
+
 			let mut kad = Kademlia::with_config(local_peer_id, store, config);
 			kad.set_mode(Some(kad::Mode::Server));
 

substrate/client/network/src/litep2p/discovery.rs

@@ -19,7 +19,10 @@
 //! libp2p-related discovery code for litep2p backend.
 
 use crate::{
-	config::{NetworkConfiguration, ProtocolId},
+	config::{
+		NetworkConfiguration, ProtocolId, KADEMLIA_MAX_PROVIDER_KEYS, KADEMLIA_PROVIDER_RECORD_TTL,
+		KADEMLIA_PROVIDER_REPUBLISH_INTERVAL,
+	},
 	peer_store::PeerStoreProvider,
 };
 
@@ -299,6 +302,9 @@ impl Discovery {
 				.with_known_peers(known_peers)
 				.with_protocol_names(protocol_names)
 				.with_incoming_records_validation_mode(IncomingRecordValidationMode::Manual)
+				.with_provider_record_ttl(KADEMLIA_PROVIDER_RECORD_TTL)
+				.with_provider_refresh_interval(KADEMLIA_PROVIDER_REPUBLISH_INTERVAL)
+				.with_max_provider_keys(KADEMLIA_MAX_PROVIDER_KEYS)
 				.build()
 		};