Move the network status reporting to the service (#2916)

* Move the network status reporting to the service

* Fix tests

* Fix build

substrate/Cargo.lock

@@ -4484,6 +4484,7 @@ dependencies = [
  "sysinfo 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "target_info 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-timer 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

substrate/core/cli/src/informant.rs

@@ -40,39 +40,36 @@ pub fn start<C>(service: &Service<C>, exit: ::exit_future::Exit, handle: TaskExe
 /// Creates an informant in the form of a `Future` that must be polled regularly.
 pub fn build<C>(service: &Service<C>) -> impl Future<Item = (), Error = ()>
 where C: Components {
-	let network = service.network();
 	let client = service.client();
 	let mut last_number = None;
 	let mut last_update = time::Instant::now();
 
-	let display_notifications = network.status().for_each(move |sync_status| {
+	let display_notifications = service.network_status().for_each(move |net_status| {
 
 		let info = client.info();
 		let best_number = info.chain.best_number.saturated_into::<u64>();
 		let best_hash = info.chain.best_hash;
 		let speed = move || speed(best_number, last_number, last_update);
 		last_update = time::Instant::now();
-		let (status, target) = match (sync_status.sync.state, sync_status.sync.best_seen_block) {
+		let (status, target) = match (net_status.sync_state, net_status.best_seen_block) {
 			(SyncState::Idle, _) => ("Idle".into(), "".into()),
 			(SyncState::Downloading, None) => (format!("Syncing{}", speed()), "".into()),
 			(SyncState::Downloading, Some(n)) => (format!("Syncing{}", speed()), format!(", target=#{}", n)),
 		};
 		last_number = Some(best_number);
 		let finalized_number: u64 = info.chain.finalized_number.saturated_into::<u64>();
-		let bandwidth_download = network.average_download_per_sec();
-		let bandwidth_upload = network.average_upload_per_sec();
 		info!(
 			target: "substrate",
 			"{}{} ({} peers), best: #{} ({}), finalized #{} ({}), ⬇ {} ⬆ {}",
 			Colour::White.bold().paint(&status),
 			target,
-			Colour::White.bold().paint(format!("{}", sync_status.num_peers)),
+			Colour::White.bold().paint(format!("{}", net_status.num_connected_peers)),
 			Colour::White.paint(format!("{}", best_number)),
 			best_hash,
 			Colour::White.paint(format!("{}", finalized_number)),
 			info.chain.finalized_hash,
-			TransferRateFormat(bandwidth_download),
-			TransferRateFormat(bandwidth_upload),
+			TransferRateFormat(net_status.average_download_per_sec),
+			TransferRateFormat(net_status.average_upload_per_sec),
 		);
 
 		Ok(())

substrate/core/network/src/lib.rs

@@ -184,8 +184,8 @@ pub use service::{
 	NetworkMsg, ExHashT, ReportHandle,
 };
 pub use config::{NodeKeyConfig, Secret, Secp256k1Secret, Ed25519Secret};
-pub use protocol::{ProtocolStatus, PeerInfo, Context, consensus_gossip, message, specialization};
-pub use protocol::sync::{Status as SyncStatus, SyncState};
+pub use protocol::{PeerInfo, Context, consensus_gossip, message, specialization};
+pub use protocol::sync::SyncState;
 pub use libp2p::{Multiaddr, multiaddr, build_multiaddr};
 pub use libp2p::{identity, PeerId, core::PublicKey};
 

substrate/core/network/src/protocol.rs

@@ -33,7 +33,7 @@ use message::generic::{Message as GenericMessage, ConsensusMessage};
 use consensus_gossip::{ConsensusGossip, MessageRecipient as GossipMessageRecipient};
 use on_demand::{OnDemandCore, OnDemandNetwork, RequestData};
 use specialization::NetworkSpecialization;
-use sync::{ChainSync, Context as SyncContext, Status as SyncStatus, SyncState};
+use sync::{ChainSync, Context as SyncContext, SyncState};
 use crate::service::{TransactionPool, ExHashT};
 use crate::config::Roles;
 use rustc_hex::ToHex;
@@ -115,17 +115,6 @@ struct HandshakingPeer {
 	timestamp: time::Instant,
 }
 
-/// Syncing status and statistics
-#[derive(Clone)]
-pub struct ProtocolStatus<B: BlockT> {
-	/// Sync status.
-	pub sync: SyncStatus<B>,
-	/// Total number of connected peers
-	pub num_peers: usize,
-	/// Total number of active peers.
-	pub num_active_peers: usize,
-}
-
 /// Peer information
 #[derive(Debug, Clone)]
 struct Peer<B: BlockT, H: ExHashT> {
@@ -415,26 +404,33 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		})
 	}
 
-	/// Returns an object representing the status of the protocol.
-	pub fn status(&self) -> ProtocolStatus<B> {
-		ProtocolStatus {
-			sync: self.sync.status(),
-			num_peers: self.context_data.peers.values().count(),
-			num_active_peers: self
-				.context_data
-				.peers
-				.values()
-				.filter(|p| p.block_request.is_some())
-				.count(),
-		}
+	/// Returns the number of peers we're connected to.
+	pub fn num_connected_peers(&self) -> usize {
+		self.context_data.peers.values().count()
 	}
 
-	pub fn is_major_syncing(&self) -> bool {
-		self.sync.status().is_major_syncing()
+	/// Returns the number of peers we're connected to and that are being queried.
+	pub fn num_active_peers(&self) -> usize {
+		self.context_data
+			.peers
+			.values()
+			.filter(|p| p.block_request.is_some())
+			.count()
 	}
 
-	pub fn is_offline(&self) -> bool {
-		self.sync.status().is_offline()
+	/// Current global sync state.
+	pub fn sync_state(&self) -> SyncState {
+		self.sync.status().state
+	}
+
+	/// Target sync block number.
+	pub fn best_seen_block(&self) -> Option<NumberFor<B>> {
+		self.sync.status().best_seen_block
+	}
+
+	/// Number of peers participating in syncing.
+	pub fn num_sync_peers(&self) -> u32 {
+		self.sync.status().num_peers
 	}
 
 	/// Starts a new data demand request.

substrate/core/network/src/protocol/sync.rs

@@ -194,22 +194,6 @@ pub struct Status<B: BlockT> {
 	pub num_peers: u32,
 }
 
-impl<B: BlockT> Status<B> {
-	/// Whether the synchronization status is doing major downloading work or
-	/// is near the head of the chain.
-	pub fn is_major_syncing(&self) -> bool {
-		match self.state {
-			SyncState::Idle => false,
-			SyncState::Downloading => true,
-		}
-	}
-
-	/// Are we all alone?
-	pub fn is_offline(&self) -> bool {
-		self.num_peers == 0
-	}
-}
-
 impl<B: BlockT> ChainSync<B> {
 	/// Create a new instance. Pass the initial known state of the chain.
 	pub(crate) fn new(role: Roles, info: &ClientInfo<B>) -> Self {

substrate/core/network/src/service.rs

@@ -39,13 +39,12 @@ use crate::protocol::consensus_gossip::{ConsensusGossip, MessageRecipient as Gos
 use crate::protocol::message::Message;
 use crate::protocol::on_demand::RequestData;
 use crate::protocol::{self, Context, CustomMessageOutcome, Protocol, ConnectedPeer};
-use crate::protocol::{ProtocolStatus, PeerInfo, NetworkOut};
+use crate::protocol::{PeerInfo, NetworkOut};
+use crate::protocol::sync::SyncState;
 use crate::config::Params;
 use crate::error::Error;
 use crate::protocol::specialization::NetworkSpecialization;
 
-/// Interval at which we send status updates on the status stream.
-const STATUS_INTERVAL: Duration = Duration::from_millis(5000);
 /// Interval at which we update the `peers` field on the main thread.
 const CONNECTED_PEERS_INTERVAL: Duration = Duration::from_millis(500);
 
@@ -90,8 +89,6 @@ impl ReportHandle {
 
 /// Substrate network service. Handles network IO and manages connectivity.
 pub struct NetworkService<B: BlockT + 'static, S: NetworkSpecialization<B>> {
-	/// Sinks to propagate status updates.
-	status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<ProtocolStatus<B>>>>>,
 	/// Are we connected to any peer?
 	is_offline: Arc<AtomicBool>,
 	/// Are we actively catching up with the chain?
@@ -122,7 +119,6 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 	) -> Result<NetworkWorker<B, S, H>, Error> {
 		let (network_chan, network_port) = mpsc::unbounded();
 		let (protocol_sender, protocol_rx) = mpsc::unbounded();
-		let status_sinks = Arc::new(Mutex::new(Vec::new()));
 
 		// Start in off-line mode, since we're not connected to any nodes yet.
 		let is_offline = Arc::new(AtomicBool::new(true));
@@ -148,7 +144,6 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 			};
 
 		let service = Arc::new(NetworkService {
-			status_sinks: status_sinks.clone(),
 			bandwidth,
 			is_offline: is_offline.clone(),
 			is_major_syncing: is_major_syncing.clone(),
@@ -172,13 +167,46 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 			finality_proof_provider: params.finality_proof_provider,
 			network_port,
 			protocol_rx,
-			status_sinks,
 			on_demand_in: params.on_demand.and_then(|od| od.extract_receiver()),
-			status_interval: tokio_timer::Interval::new_interval(STATUS_INTERVAL),
 			connected_peers_interval: tokio_timer::Interval::new_interval(CONNECTED_PEERS_INTERVAL),
 		})
 	}
 
+	/// Returns the downloaded bytes per second averaged over the past few seconds.
+	pub fn average_download_per_sec(&self) -> u64 {
+		self.service.bandwidth.average_download_per_sec()
+	}
+
+	/// Returns the uploaded bytes per second averaged over the past few seconds.
+	pub fn average_upload_per_sec(&self) -> u64 {
+		self.service.bandwidth.average_upload_per_sec()
+	}
+
+	/// Returns the number of peers we're connected to.
+	pub fn num_connected_peers(&self) -> usize {
+		self.protocol.num_connected_peers()
+	}
+
+	/// Returns the number of peers we're connected to and that are being queried.
+	pub fn num_active_peers(&self) -> usize {
+		self.protocol.num_active_peers()
+	}
+
+	/// Current global sync state.
+	pub fn sync_state(&self) -> SyncState {
+		self.protocol.sync_state()
+	}
+
+	/// Target sync block number.
+	pub fn best_seen_block(&self) -> Option<NumberFor<B>> {
+		self.protocol.best_seen_block()
+	}
+
+	/// Number of peers participating in syncing.
+	pub fn num_sync_peers(&self) -> u32 {
+		self.protocol.num_sync_peers()
+	}
+
 	/// Return a `NetworkService` that can be shared through the code base and can be used to
 	/// manipulate the worker.
 	pub fn service(&self) -> &Arc<NetworkService<B, S>> {
@@ -187,16 +215,6 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 }
 
 impl<B: BlockT + 'static, S: NetworkSpecialization<B>> NetworkService<B, S> {
-	/// Returns the downloaded bytes per second averaged over the past few seconds.
-	pub fn average_download_per_sec(&self) -> u64 {
-		self.bandwidth.average_download_per_sec()
-	}
-
-	/// Returns the uploaded bytes per second averaged over the past few seconds.
-	pub fn average_upload_per_sec(&self) -> u64 {
-		self.bandwidth.average_upload_per_sec()
-	}
-
 	/// Returns the network identity of the node.
 	pub fn local_peer_id(&self) -> PeerId {
 		Swarm::<B>::local_peer_id(&*self.network.lock()).clone()
@@ -287,13 +305,6 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>> NetworkService<B, S> {
 		self.is_major_syncing.load(Ordering::Relaxed)
 	}
 
-	/// Get sync status
-	pub fn status(&self) -> mpsc::UnboundedReceiver<ProtocolStatus<B>> {
-		let (sink, stream) = mpsc::unbounded();
-		self.status_sinks.lock().push(sink);
-		stream
-	}
-
 	/// Get network state.
 	pub fn network_state(&self) -> NetworkState {
 		let mut swarm = self.network.lock();
@@ -497,12 +508,9 @@ pub struct NetworkWorker<B: BlockT + 'static, S: NetworkSpecialization<B>, H: Ex
 	finality_proof_provider: Option<Arc<dyn FinalityProofProvider<B>>>,
 	network_port: mpsc::UnboundedReceiver<NetworkMsg<B>>,
 	protocol_rx: mpsc::UnboundedReceiver<ProtocolMsg<B, S>>,
-	status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<ProtocolStatus<B>>>>>,
 	peerset: PeersetHandle,
 	on_demand_in: Option<mpsc::UnboundedReceiver<RequestData<B>>>,
 
-	/// Interval at which we send status updates on the `status_sinks`.
-	status_interval: tokio_timer::Interval,
 	/// Interval at which we update the `connected_peers` Arc.
 	connected_peers_interval: tokio_timer::Interval,
 }
@@ -580,11 +588,6 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> Future for Ne
 			}
 		}
 
-		while let Ok(Async::Ready(_)) = self.status_interval.poll() {
-			let status = self.protocol.status();
-			self.status_sinks.lock().retain(|sink| sink.unbounded_send(status.clone()).is_ok());
-		}
-
 		{
 			let mut network_service = self.network_service.lock();
 			let mut link = NetworkLink {
@@ -742,8 +745,11 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> Future for Ne
 			}
 		}
 
-		self.is_offline.store(self.protocol.is_offline(), Ordering::Relaxed);
-		self.is_major_syncing.store(self.protocol.is_major_syncing(), Ordering::Relaxed);
+		self.is_offline.store(self.protocol.num_connected_peers() == 0, Ordering::Relaxed);
+		self.is_major_syncing.store(match self.protocol.sync_state() {
+			SyncState::Idle => false,
+			SyncState::Downloading => true,
+		}, Ordering::Relaxed);
 
 		Ok(Async::NotReady)
 	}

substrate/core/network/src/test/mod.rs

@@ -46,7 +46,8 @@ use crate::message::Message;
 use libp2p::PeerId;
 use parking_lot::{Mutex, RwLock};
 use primitives::{H256, Blake2Hasher};
-use crate::protocol::{Context, Protocol, ProtocolConfig, ProtocolStatus, CustomMessageOutcome, NetworkOut};
+use crate::SyncState;
+use crate::protocol::{Context, Protocol, ProtocolConfig, CustomMessageOutcome, NetworkOut};
 use runtime_primitives::generic::{BlockId, OpaqueDigestItemId};
 use runtime_primitives::traits::{Block as BlockT, Header, NumberFor};
 use runtime_primitives::{Justification, ConsensusEngineId};
@@ -365,7 +366,8 @@ pub struct Peer<D, S: NetworkSpecialization<Block>> {
 	/// instantiation paths or field names is too much hassle, hence
 	/// we allow it to be unused.
 	#[cfg_attr(not(test), allow(unused))]
-	protocol_status: Arc<RwLock<ProtocolStatus<Block>>>,
+	/// `(is_offline, is_major_syncing, num_peers)`
+	protocol_status: Arc<RwLock<(bool, bool, usize)>>,
 	import_queue: Arc<Mutex<Box<BasicQueue<Block>>>>,
 	pub data: D,
 	best_hash: Mutex<Option<H256>>,
@@ -509,7 +511,7 @@ impl<S: NetworkSpecialization<Block>> ProtocolChannel<S> {
 
 impl<D, S: NetworkSpecialization<Block>> Peer<D, S> {
 	fn new(
-		protocol_status: Arc<RwLock<ProtocolStatus<Block>>>,
+		protocol_status: Arc<RwLock<(bool, bool, usize)>>,
 		client: PeersClient,
 		import_queue: Arc<Mutex<Box<BasicQueue<Block>>>>,
 		use_tokio: bool,
@@ -560,19 +562,19 @@ impl<D, S: NetworkSpecialization<Block>> Peer<D, S> {
 	/// SyncOracle: are we connected to any peer?
 	#[cfg(test)]
 	fn is_offline(&self) -> bool {
-		self.protocol_status.read().sync.is_offline()
+		self.protocol_status.read().0
 	}
 
 	/// SyncOracle: are we in the process of catching-up with the chain?
 	#[cfg(test)]
 	fn is_major_syncing(&self) -> bool {
-		self.protocol_status.read().sync.is_major_syncing()
+		self.protocol_status.read().1
 	}
 
 	/// Get protocol status.
 	#[cfg(test)]
-	fn protocol_status(&self) -> ProtocolStatus<Block> {
-		self.protocol_status.read().clone()
+	fn num_peers(&self) -> usize {
+		self.protocol_status.read().2
 	}
 
 	/// Called on connection to other indicated peer.
@@ -873,7 +875,7 @@ pub trait TestNetFactory: Sized {
 	/// Add created peer.
 	fn add_peer(
 		&mut self,
-		protocol_status: Arc<RwLock<ProtocolStatus<Block>>>,
+		protocol_status: Arc<RwLock<(bool, bool, usize)>>,
 		import_queue: Arc<Mutex<Box<BasicQueue<Block>>>>,
 		tx_pool: EmptyTransactionPool,
 		finality_proof_provider: Option<Arc<dyn FinalityProofProvider<Block>>>,
@@ -1009,7 +1011,11 @@ pub trait TestNetFactory: Sized {
 					return Ok(Async::Ready(()))
 				}
 
-				*protocol_status.write() = protocol.status();
+				*protocol_status.write() = (
+					protocol.num_connected_peers() == 0,
+					protocol.sync_state() == SyncState::Downloading,
+					protocol.num_connected_peers()
+				);
 				Ok(Async::NotReady)
 			}));
 		});
@@ -1054,7 +1060,7 @@ pub trait TestNetFactory: Sized {
 			specialization,
 		).unwrap();
 
-		let protocol_status = Arc::new(RwLock::new(protocol.status()));
+		let protocol_status = Arc::new(RwLock::new((true, false, 0)));
 		self.add_peer(
 			protocol_status.clone(),
 			import_queue.clone(),
@@ -1110,7 +1116,7 @@ pub trait TestNetFactory: Sized {
 			specialization,
 		).unwrap();
 
-		let protocol_status = Arc::new(RwLock::new(protocol.status()));
+		let protocol_status = Arc::new(RwLock::new((true, false, 0)));
 		self.add_peer(
 			protocol_status.clone(),
 			import_queue.clone(),

substrate/core/network/src/test/sync.rs

@@ -45,7 +45,7 @@ fn sync_peers_works() {
 	net.sync();
 	for peer in 0..3 {
 		// Assert peers is up to date.
-		assert_eq!(net.peer(peer).protocol_status.read().num_peers, 2);
+		assert_eq!(net.peer(peer).num_peers(), 2);
 		// And then disconnect.
 		for other in 0..3 {
 			if other != peer {
@@ -56,8 +56,7 @@ fn sync_peers_works() {
 	net.sync();
 	// Now peers are disconnected.
 	for peer in 0..3 {
-		let status = net.peer(peer).protocol_status.read();
-		assert_eq!(status.num_peers, 0);
+		assert_eq!(net.peer(peer).num_peers(), 0);
 	}
 }
 
@@ -433,7 +432,7 @@ fn can_not_sync_from_light_peer() {
 	assert_eq!(net.peer(2).client.info().chain.best_number, 0);
 	// and that the #1 is still connected to #2
 	// (because #2 has not tried to fetch block data from the #1 light node)
-	assert_eq!(net.peer(1).protocol_status().num_peers, 2);
+	assert_eq!(net.peer(1).num_peers(), 2);
 
 	// and now try to fetch block data from light peer #1
 	// (this should result in disconnect)
@@ -450,7 +449,7 @@ fn can_not_sync_from_light_peer() {
 	);
 	net.sync();
 	// check that light #1 has disconnected from #2
-	assert_eq!(net.peer(1).protocol_status().num_peers, 1);
+	assert_eq!(net.peer(1).num_peers(), 1);
 }
 
 #[test]

substrate/core/service/Cargo.toml

@@ -12,6 +12,7 @@ lazy_static = "1.0"
 log = "0.4"
 slog = {version = "^2", features = ["nested-values"]}
 tokio = "0.1.7"
+tokio-timer = "0.2"
 exit-future = "0.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"

substrate/core/service/src/lib.rs

@@ -28,6 +28,7 @@ pub mod error;
 use std::io;
 use std::net::SocketAddr;
 use std::collections::HashMap;
+use std::time::Duration;
 use futures::sync::mpsc;
 use parking_lot::Mutex;
 
@@ -39,7 +40,7 @@ use log::{info, warn, debug};
 use parity_codec::{Encode, Decode};
 use primitives::Pair;
 use runtime_primitives::generic::BlockId;
-use runtime_primitives::traits::{Header, SaturatedConversion};
+use runtime_primitives::traits::{Header, NumberFor, SaturatedConversion};
 use substrate_executor::NativeExecutor;
 use sysinfo::{get_current_pid, ProcessExt, System, SystemExt};
 use tel::{telemetry, SUBSTRATE_INFO};
@@ -75,6 +76,8 @@ pub struct Service<Components: components::Components> {
 	client: Arc<ComponentClient<Components>>,
 	select_chain: Option<<Components as components::Components>::SelectChain>,
 	network: Arc<components::NetworkService<Components::Factory>>,
+	/// Sinks to propagate network status updates.
+	network_status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<NetworkStatus<ComponentBlock<Components>>>>>>,
 	transaction_pool: Arc<TransactionPool<Components::TransactionPoolApi>>,
 	keystore: Keystore,
 	exit: ::exit_future::Exit,
@@ -204,8 +207,9 @@ impl<Components: components::Components> Service<Components> {
 		let has_bootnodes = !network_params.network_config.boot_nodes.is_empty();
 		let network_mut = network::NetworkWorker::new(network_params)?;
 		let network = network_mut.service().clone();
+		let network_status_sinks = Arc::new(Mutex::new(Vec::new()));
 
-		task_executor.spawn(network_mut
+		task_executor.spawn(build_network_future(network_mut, network_status_sinks.clone())
 			.map_err(|_| ())
 			.select(exit.clone())
 			.then(|_| Ok(())));
@@ -331,15 +335,17 @@ impl<Components: components::Components> Service<Components> {
 		let network_ = network.clone();
 		let mut sys = System::new();
 		let self_pid = get_current_pid();
-		task_executor.spawn(network.status().for_each(move |sync_status| {
+		let (netstat_tx, netstat_rx) = mpsc::unbounded();
+		network_status_sinks.lock().push(netstat_tx);
+		task_executor.spawn(netstat_rx.for_each(move |net_status| {
 			let info = client_.info();
 			let best_number = info.chain.best_number.saturated_into::<u64>();
 			let best_hash = info.chain.best_hash;
-			let num_peers = sync_status.num_peers;
+			let num_peers = net_status.num_connected_peers;
 			let txpool_status = transaction_pool_.status();
 			let finalized_number: u64 = info.chain.finalized_number.saturated_into::<u64>();
-			let bandwidth_download = network_.average_download_per_sec();
-			let bandwidth_upload = network_.average_upload_per_sec();
+			let bandwidth_download = net_status.average_download_per_sec;
+			let bandwidth_upload = net_status.average_upload_per_sec;
 
 			#[allow(deprecated)]
 			let backend = (*client_).backend();
@@ -447,6 +453,7 @@ impl<Components: components::Components> Service<Components> {
 		Ok(Service {
 			client,
 			network,
+			network_status_sinks,
 			select_chain,
 			transaction_pool,
 			signal: Some(signal),
@@ -495,6 +502,13 @@ impl<Components> Service<Components> where Components: components::Components {
 		self.network.clone()
 	}
 
+	/// Returns a receiver that periodically receives a status of the network.
+	pub fn network_status(&self) -> mpsc::UnboundedReceiver<NetworkStatus<ComponentBlock<Components>>> {
+		let (sink, stream) = mpsc::unbounded();
+		self.network_status_sinks.lock().push(sink);
+		stream
+	}
+
 	/// Get shared transaction pool instance.
 	pub fn transaction_pool(&self) -> Arc<TransactionPool<Components::TransactionPoolApi>> {
 		self.transaction_pool.clone()
@@ -511,6 +525,57 @@ impl<Components> Service<Components> where Components: components::Components {
 	}
 }
 
+/// Builds a never-ending future that continuously polls the network.
+///
+/// The `status_sink` contain a list of senders to send a periodic network status to.
+fn build_network_future<B: BlockT, S: network::specialization::NetworkSpecialization<B>, H: network::ExHashT>(
+	mut network: network::NetworkWorker<B, S, H>,
+	status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<NetworkStatus<B>>>>>,
+) -> impl Future<Item = (), Error = ()> {
+	// Interval at which we send status updates on the status stream.
+	const STATUS_INTERVAL: Duration = Duration::from_millis(5000);
+	let mut status_interval = tokio_timer::Interval::new_interval(STATUS_INTERVAL);
+
+	futures::future::poll_fn(move || {
+		while let Ok(Async::Ready(_)) = status_interval.poll() {
+			let status = NetworkStatus {
+				sync_state: network.sync_state(),
+				best_seen_block: network.best_seen_block(),
+				num_sync_peers: network.num_sync_peers(),
+				num_connected_peers: network.num_connected_peers(),
+				num_active_peers: network.num_active_peers(),
+				average_download_per_sec: network.average_download_per_sec(),
+				average_upload_per_sec: network.average_upload_per_sec(),
+			};
+
+			status_sinks.lock().retain(|sink| sink.unbounded_send(status.clone()).is_ok());
+		}
+
+		network.poll()
+			.map_err(|err| {
+				warn!(target: "service", "Error in network: {:?}", err);
+			})
+	})
+}
+
+/// Overview status of the network.
+#[derive(Clone)]
+pub struct NetworkStatus<B: BlockT> {
+	/// Current global sync state.
+	pub sync_state: network::SyncState,
+	/// Target sync block number.
+	pub best_seen_block: Option<NumberFor<B>>,
+	/// Number of peers participating in syncing.
+	pub num_sync_peers: u32,
+	/// Total number of connected peers
+	pub num_connected_peers: usize,
+	/// Total number of active peers.
+	pub num_active_peers: usize,
+	/// Downloaded bytes per second averaged over the past few seconds.
+	pub average_download_per_sec: u64,
+	/// Uploaded bytes per second averaged over the past few seconds.
+	pub average_upload_per_sec: u64,
+}
 
 impl<Components> Drop for Service<Components> where Components: components::Components {
 	fn drop(&mut self) {