net/discovery: File persistence for AddrCache

Cargo.toml

@@ -1275,6 +1275,7 @@ serde = { version = "1.0.214", default-features = false }
 serde-big-array = { version = "0.3.2" }
 serde_derive = { version = "1.0.117" }
 serde_json = { version = "1.0.132", default-features = false }
+serde_with = { version = "3.12.0", default-features = false, features = ["hex", "macros"] }
 serde_yaml = { version = "0.9" }
 sha1 = { version = "0.10.6" }
 sha2 = { version = "0.10.7", default-features = false }

cumulus/client/relay-chain-minimal-node/src/lib.rs

@@ -69,19 +69,22 @@ fn build_authority_discovery_service<Block: BlockT>(
 			_ => None,
 		}
 	});
+	let net_config_path = config.network.net_config_path.clone();
 	let (worker, service) = sc_authority_discovery::new_worker_and_service_with_config(
 		sc_authority_discovery::WorkerConfig {
 			publish_non_global_ips: auth_disc_publish_non_global_ips,
 			public_addresses: auth_disc_public_addresses,
 			// Require that authority discovery records are signed.
 			strict_record_validation: true,
+			persisted_cache_directory: net_config_path,
 			..Default::default()
 		},
 		client,
 		Arc::new(network.clone()),
 		Box::pin(dht_event_stream),
 		authority_discovery_role,
 		prometheus_registry,
+		task_manager.spawn_handle(),
 	);
 
 	task_manager.spawn_handle().spawn(

polkadot/node/service/src/builder/mod.rs

@@ -480,6 +480,7 @@ where
 			);
 		}
 
+		let network_config = config.network.clone();
 		let rpc_handlers = sc_service::spawn_tasks(sc_service::SpawnTasksParams {
 			config,
 			backend: backend.clone(),
@@ -568,13 +569,15 @@ where
 					public_addresses: auth_disc_public_addresses,
 					// Require that authority discovery records are signed.
 					strict_record_validation: true,
+					persisted_cache_directory: network_config.net_config_path,
 					..Default::default()
 				},
 				client.clone(),
 				Arc::new(network.clone()),
 				Box::pin(dht_event_stream),
 				authority_discovery_role,
 				prometheus_registry.clone(),
+				task_manager.spawn_handle(),
 			);
 
 			task_manager.spawn_handle().spawn(

prdoc/pr_8839.prdoc

@@ -0,0 +1,23 @@
+title: "net/discovery: File persistence for AddrCache"
+doc:
+  - audience: Node Dev
+    description: |-
+      Persisting the AddrCache periodically (every 10 minutes) and on worker 
+      shutdown. Read AddrCache from file upon launch of worker.
+
+      AddrCache is saved as authority_discovery_addr_cache.json in the 
+      folder configured by net_config_path of NetworkConfiguration.
+
+      This reduces the time it takes for a node to reconnect to peers after
+      restart.
+crates:
+  - name: sc-authority-discovery
+    bump: major
+  - name: sc-network-types
+    bump: minor
+  - name: cumulus-relay-chain-minimal-node
+    bump: patch
+  - name: polkadot-service
+    bump: patch
+  - name: staging-node-cli
+    bump: patch

substrate/bin/node/cli/src/service.rs

@@ -547,6 +547,7 @@ pub fn new_full_base<N: NetworkBackend<Block, <Block as BlockT>::Hash>>(
 		task_manager.spawn_handle().spawn("mixnet", None, mixnet);
 	}
 
+	let net_config_path = config.network.net_config_path.clone();
 	let rpc_handlers = sc_service::spawn_tasks(sc_service::SpawnTasksParams {
 		config,
 		backend: backend.clone(),
@@ -659,13 +660,15 @@ pub fn new_full_base<N: NetworkBackend<Block, <Block as BlockT>::Hash>>(
 				sc_authority_discovery::WorkerConfig {
 					publish_non_global_ips: auth_disc_publish_non_global_ips,
 					public_addresses: auth_disc_public_addresses,
+					persisted_cache_directory: net_config_path,
 					..Default::default()
 				},
 				client.clone(),
 				Arc::new(network.clone()),
 				Box::pin(dht_event_stream),
 				authority_discovery_role,
 				prometheus_registry.clone(),
+				task_manager.spawn_handle(),
 			);
 
 		task_manager.spawn_handle().spawn(

substrate/client/authority-discovery/Cargo.toml

@@ -30,18 +30,24 @@ rand = { workspace = true, default-features = true }
 sc-client-api = { workspace = true, default-features = true }
 sc-network = { workspace = true, default-features = true }
 sc-network-types = { workspace = true, default-features = true }
+sc-service.workspace = true
+serde.workspace = true
+serde_json.workspace = true
 sp-api = { workspace = true, default-features = true }
 sp-authority-discovery = { workspace = true, default-features = true }
 sp-blockchain = { workspace = true, default-features = true }
 sp-core = { workspace = true, default-features = true }
 sp-keystore = { workspace = true, default-features = true }
 sp-runtime = { workspace = true, default-features = true }
 thiserror = { workspace = true }
+tokio.workspace = true
 
 [dev-dependencies]
+hex.workspace = true
 quickcheck = { workspace = true }
 sp-tracing = { workspace = true, default-features = true }
 substrate-test-runtime-client = { workspace = true }
+tempfile.workspace = true
 
 [build-dependencies]
 prost-build = { workspace = true }

substrate/client/authority-discovery/src/error.rs

@@ -52,6 +52,9 @@ pub enum Error {
 	#[error("Failed to encode or decode scale payload.")]
 	EncodingDecodingScale(#[from] codec::Error),
 
+	#[error("Failed to encode or decode AddrCache.")]
+	EncodingDecodingAddrCache(String),
+
 	#[error("Failed to parse a libp2p multi address.")]
 	ParsingMultiaddress(#[from] sc_network::multiaddr::ParseError),
 

substrate/client/authority-discovery/src/lib.rs

@@ -33,7 +33,7 @@ pub use crate::{
 	worker::{AuthorityDiscovery, NetworkProvider, Role, Worker},
 };
 
-use std::{collections::HashSet, sync::Arc, time::Duration};
+use std::{collections::HashSet, path::PathBuf, sync::Arc, time::Duration};
 
 use futures::{
 	channel::{mpsc, oneshot},
@@ -44,8 +44,8 @@ use sc_network::{event::DhtEvent, Multiaddr};
 use sc_network_types::PeerId;
 use sp_authority_discovery::AuthorityId;
 use sp_blockchain::HeaderBackend;
+use sp_core::traits::SpawnNamed;
 use sp_runtime::traits::Block as BlockT;
-
 mod error;
 mod interval;
 mod service;
@@ -88,6 +88,11 @@ pub struct WorkerConfig {
 	///
 	/// Defaults to `false` to provide compatibility with old versions
 	pub strict_record_validation: bool,
+
+	/// The directory of where the persisted AddrCache file is located,
+	/// optional since NetworkConfiguration's `net_config_path` field
+	/// is optional. If None, we won't persist the AddrCache at all.
+	pub persisted_cache_directory: Option<PathBuf>,
 }
 
 impl Default for WorkerConfig {
@@ -110,6 +115,7 @@ impl Default for WorkerConfig {
 			publish_non_global_ips: true,
 			public_addresses: Vec::new(),
 			strict_record_validation: false,
+			persisted_cache_directory: None,
 		}
 	}
 }
@@ -123,6 +129,7 @@ pub fn new_worker_and_service<Client, Block, DhtEventStream>(
 	dht_event_rx: DhtEventStream,
 	role: Role,
 	prometheus_registry: Option<prometheus_endpoint::Registry>,
+	spawner: impl SpawnNamed + 'static,
 ) -> (Worker<Client, Block, DhtEventStream>, Service)
 where
 	Block: BlockT + Unpin + 'static,
@@ -136,6 +143,7 @@ where
 		dht_event_rx,
 		role,
 		prometheus_registry,
+		spawner,
 	)
 }
 
@@ -149,6 +157,7 @@ pub fn new_worker_and_service_with_config<Client, Block, DhtEventStream>(
 	dht_event_rx: DhtEventStream,
 	role: Role,
 	prometheus_registry: Option<prometheus_endpoint::Registry>,
+	spawner: impl SpawnNamed + 'static,
 ) -> (Worker<Client, Block, DhtEventStream>, Service)
 where
 	Block: BlockT + Unpin + 'static,
@@ -157,8 +166,16 @@ where
 {
 	let (to_worker, from_service) = mpsc::channel(0);
 
-	let worker =
-		Worker::new(from_service, client, network, dht_event_rx, role, prometheus_registry, config);
+	let worker = Worker::new(
+		from_service,
+		client,
+		network,
+		dht_event_rx,
+		role,
+		prometheus_registry,
+		config,
+		spawner,
+	);
 	let service = Service::new(to_worker);
 
 	(worker, service)