layout: separate code path for synchronizing update trackers only

src/rpc/layout/history.rs

@@ -18,10 +18,11 @@ impl LayoutHistory {
 		let mut ret = LayoutHistory {
 			versions: vec![version].into_boxed_slice().into(),
 			update_trackers: Default::default(),
+			trackers_hash: [0u8; 32].into(),
 			staging: Lww::raw(0, staging),
 			staging_hash: [0u8; 32].into(),
 		};
-		ret.staging_hash = ret.calculate_staging_hash();
+		ret.update_hashes();
 		ret
 	}
 
@@ -29,6 +30,15 @@ impl LayoutHistory {
 		self.versions.last().as_ref().unwrap()
 	}
 
+	pub(crate) fn update_hashes(&mut self) {
+		self.trackers_hash = self.calculate_trackers_hash();
+		self.staging_hash = self.calculate_staging_hash();
+	}
+
+	pub(crate) fn calculate_trackers_hash(&self) -> Hash {
+		blake2sum(&nonversioned_encode(&self.update_trackers).unwrap()[..])
+	}
+
 	pub(crate) fn calculate_staging_hash(&self) -> Hash {
 		blake2sum(&nonversioned_encode(&self.staging).unwrap()[..])
 	}
@@ -38,12 +48,6 @@ impl LayoutHistory {
 	pub fn merge(&mut self, other: &LayoutHistory) -> bool {
 		let mut changed = false;
 
-		// Merge staged layout changes
-		if self.staging != other.staging {
-			changed = true;
-		}
-		self.staging.merge(&other.staging);
-
 		// Add any new versions to history
 		for v2 in other.versions.iter() {
 			if let Some(v1) = self.versions.iter().find(|v| v.version == v2.version) {
@@ -63,7 +67,21 @@ impl LayoutHistory {
 		}
 
 		// Merge trackers
-		self.update_trackers.merge(&other.update_trackers);
+		if self.update_trackers != other.update_trackers {
+			let c = self.update_trackers.merge(&other.update_trackers);
+			changed = changed || c;
+		}
+
+		// Merge staged layout changes
+		if self.staging != other.staging {
+			self.staging.merge(&other.staging);
+			changed = true;
+		}
+
+		// Update hashes if there are changes
+		if changed {
+			self.update_hashes();
+		}
 
 		changed
 	}
@@ -100,7 +118,7 @@ To know the correct value of the new layout version, invoke `garage layout show`
 			parameters: self.staging.get().parameters.clone(),
 			roles: LwwMap::new(),
 		});
-		self.staging_hash = self.calculate_staging_hash();
+		self.update_hashes();
 
 		Ok((self, msg))
 	}
@@ -110,20 +128,25 @@ To know the correct value of the new layout version, invoke `garage layout show`
 			parameters: Lww::new(self.current().parameters.clone()),
 			roles: LwwMap::new(),
 		});
-		self.staging_hash = self.calculate_staging_hash();
+		self.update_hashes();
 
 		Ok(self)
 	}
 
 	pub fn check(&self) -> Result<(), String> {
 		// Check that the hash of the staging data is correct
-		let staging_hash = self.calculate_staging_hash();
+		if self.trackers_hash != self.calculate_trackers_hash() {
-		if staging_hash != self.staging_hash {
+			return Err("trackers_hash is incorrect".into());
+		}
+		if self.staging_hash != self.calculate_staging_hash() {
 			return Err("staging_hash is incorrect".into());
 		}
 
-		// TODO: anythign more ?
+		for version in self.versions.iter() {
+			version.check()?;
+		}
 
-		self.current().check()
+		// TODO: anythign more ?
+		Ok(())
 	}
 }

src/rpc/layout/manager.rs

@@ -19,6 +19,7 @@ use crate::rpc_helper::*;
 use crate::system::*;
 
 pub struct LayoutManager {
+	node_id: Uuid,
 	replication_factor: usize,
 	persist_cluster_layout: Persister<LayoutHistory>,
 
@@ -34,7 +35,7 @@ pub struct LayoutStatus {
 	/// Cluster layout version
 	pub cluster_layout_version: u64,
 	/// Hash of cluster layout update trackers
-	// (TODO) pub cluster_layout_trackers_hash: Hash,
+	pub cluster_layout_trackers_hash: Hash,
 	/// Hash of cluster layout staging data
 	pub cluster_layout_staging_hash: Hash,
 }
@@ -81,6 +82,7 @@ impl LayoutManager {
 		);
 
 		Ok(Arc::new(Self {
+			node_id: node_id.into(),
 			replication_factor,
 			persist_cluster_layout,
 			layout,
@@ -92,10 +94,15 @@ impl LayoutManager {
 
 	// ---- PUBLIC INTERFACE ----
 
+	pub fn layout(&self) -> RwLockReadGuard<'_, LayoutHistory> {
+		self.layout.read().unwrap()
+	}
+
 	pub fn status(&self) -> LayoutStatus {
 		let layout = self.layout();
 		LayoutStatus {
 			cluster_layout_version: layout.current().version,
+			cluster_layout_trackers_hash: layout.trackers_hash,
 			cluster_layout_staging_hash: layout.staging_hash,
 		}
 	}
@@ -108,37 +115,8 @@ impl LayoutManager {
 		Ok(())
 	}
 
-	pub fn layout(&self) -> RwLockReadGuard<'_, LayoutHistory> {
-		self.layout.read().unwrap()
-	}
-
-	pub(crate) async fn pull_cluster_layout(self: &Arc<Self>, peer: Uuid) {
-		let resp = self
-			.rpc_helper
-			.call(
-				&self.system_endpoint,
-				peer,
-				SystemRpc::PullClusterLayout,
-				RequestStrategy::with_priority(PRIO_HIGH),
-			)
-			.await;
-		if let Ok(SystemRpc::AdvertiseClusterLayout(layout)) = resp {
-			let _: Result<_, _> = self.handle_advertise_cluster_layout(&layout).await;
-		}
-	}
-
 	// ---- INTERNALS ---
 
-	/// Save network configuration to disc
-	async fn save_cluster_layout(&self) -> Result<(), Error> {
-		let layout = self.layout.read().unwrap().clone(); // TODO: avoid cloning
-		self.persist_cluster_layout
-			.save_async(&layout)
-			.await
-			.expect("Cannot save current cluster layout");
-		Ok(())
-	}
-
 	fn merge_layout(&self, adv: &LayoutHistory) -> Option<LayoutHistory> {
 		let mut layout = self.layout.write().unwrap();
 		let prev_layout_check = layout.check().is_ok();
@@ -155,17 +133,98 @@ impl LayoutManager {
 		None
 	}
 
+	fn merge_layout_trackers(&self, adv: &UpdateTrackers) -> Option<UpdateTrackers> {
+		let mut layout = self.layout.write().unwrap();
+		if layout.update_trackers != *adv {
+			if layout.update_trackers.merge(adv) {
+				return Some(layout.update_trackers.clone());
+			}
+		}
+		None
+	}
+
+	async fn pull_cluster_layout(self: &Arc<Self>, peer: Uuid) {
+		let resp = self
+			.rpc_helper
+			.call(
+				&self.system_endpoint,
+				peer,
+				SystemRpc::PullClusterLayout,
+				RequestStrategy::with_priority(PRIO_HIGH),
+			)
+			.await;
+		if let Ok(SystemRpc::AdvertiseClusterLayout(layout)) = resp {
+			if let Err(e) = self.handle_advertise_cluster_layout(&layout).await {
+				warn!("In pull_cluster_layout: {}", e);
+			}
+		}
+	}
+
+	async fn pull_cluster_layout_trackers(self: &Arc<Self>, peer: Uuid) {
+		let resp = self
+			.rpc_helper
+			.call(
+				&self.system_endpoint,
+				peer,
+				SystemRpc::PullClusterLayoutTrackers,
+				RequestStrategy::with_priority(PRIO_HIGH),
+			)
+			.await;
+		if let Ok(SystemRpc::AdvertiseClusterLayoutTrackers(trackers)) = resp {
+			if let Err(e) = self
+				.handle_advertise_cluster_layout_trackers(&trackers)
+				.await
+			{
+				warn!("In pull_cluster_layout_trackers: {}", e);
+			}
+		}
+	}
+
+	/// Save cluster layout data to disk
+	async fn save_cluster_layout(&self) -> Result<(), Error> {
+		let layout = self.layout.read().unwrap().clone();
+		self.persist_cluster_layout
+			.save_async(&layout)
+			.await
+			.expect("Cannot save current cluster layout");
+		Ok(())
+	}
+
+	fn broadcast_update(self: &Arc<Self>, rpc: SystemRpc) {
+		tokio::spawn({
+			let this = self.clone();
+			async move {
+				if let Err(e) = this
+					.rpc_helper
+					.broadcast(
+						&this.system_endpoint,
+						rpc,
+						RequestStrategy::with_priority(PRIO_HIGH),
+					)
+					.await
+				{
+					warn!("Error while broadcasting new cluster layout: {}", e);
+				}
+			}
+		});
+	}
+
 	// ---- RPC HANDLERS ----
 
-	pub(crate) fn handle_advertise_status(self: &Arc<Self>, from: Uuid, status: &LayoutStatus) {
+	pub(crate) fn handle_advertise_status(self: &Arc<Self>, from: Uuid, remote: &LayoutStatus) {
-		let local_status = self.status();
+		let local = self.status();
-		if status.cluster_layout_version > local_status.cluster_layout_version
+		if remote.cluster_layout_version > local.cluster_layout_version
-			|| status.cluster_layout_staging_hash != local_status.cluster_layout_staging_hash
+			|| remote.cluster_layout_staging_hash != local.cluster_layout_staging_hash
 		{
 			tokio::spawn({
 				let this = self.clone();
 				async move { this.pull_cluster_layout(from).await }
 			});
+		} else if remote.cluster_layout_trackers_hash != local.cluster_layout_trackers_hash {
+			tokio::spawn({
+				let this = self.clone();
+				async move { this.pull_cluster_layout_trackers(from).await }
+			});
 		}
 	}
 
@@ -174,6 +233,11 @@ impl LayoutManager {
 		SystemRpc::AdvertiseClusterLayout(layout)
 	}
 
+	pub(crate) fn handle_pull_cluster_layout_trackers(&self) -> SystemRpc {
+		let layout = self.layout.read().unwrap();
+		SystemRpc::AdvertiseClusterLayoutTrackers(layout.update_trackers.clone())
+	}
+
 	pub(crate) async fn handle_advertise_cluster_layout(
 		self: &Arc<Self>,
 		adv: &LayoutHistory,
@@ -190,24 +254,20 @@ impl LayoutManager {
 
 		if let Some(new_layout) = self.merge_layout(adv) {
 			self.change_notify.notify_waiters();
-
+			self.broadcast_update(SystemRpc::AdvertiseClusterLayout(new_layout));
-			tokio::spawn({
+			self.save_cluster_layout().await?;
-				let this = self.clone();
-				async move {
-					if let Err(e) = this
-						.rpc_helper
-						.broadcast(
-							&this.system_endpoint,
-							SystemRpc::AdvertiseClusterLayout(new_layout),
-							RequestStrategy::with_priority(PRIO_HIGH),
-						)
-						.await
-					{
-						warn!("Error while broadcasting new cluster layout: {}", e);
 		}
-				}
-			});
 
+		Ok(SystemRpc::Ok)
+	}
+
+	pub(crate) async fn handle_advertise_cluster_layout_trackers(
+		self: &Arc<Self>,
+		trackers: &UpdateTrackers,
+	) -> Result<SystemRpc, Error> {
+		if let Some(new_trackers) = self.merge_layout_trackers(trackers) {
+			self.change_notify.notify_waiters();
+			self.broadcast_update(SystemRpc::AdvertiseClusterLayoutTrackers(new_trackers));
 			self.save_cluster_layout().await?;
 		}
 

src/rpc/layout/schema.rs

@@ -233,6 +233,8 @@ mod v010 {
 
 		/// Update trackers
 		pub update_trackers: UpdateTrackers,
+		/// Hash of the update trackers
+		pub trackers_hash: Hash,
 
 		/// Staged changes for the next version
 		pub staging: Lww<LayoutStaging>,
@@ -289,10 +291,12 @@ mod v010 {
 					sync_map: update_tracker.clone(),
 					sync_ack_map: update_tracker.clone(),
 				},
+				trackers_hash: [0u8; 32].into(),
 				staging: Lww::raw(previous.version, staging),
 				staging_hash: [0u8; 32].into(),
 			};
 			ret.staging_hash = ret.calculate_staging_hash();
+			ret.trackers_hash = ret.calculate_trackers_hash();
 			ret
 		}
 	}
@@ -355,14 +359,20 @@ impl core::str::FromStr for ZoneRedundancy {
 }
 
 impl UpdateTracker {
-	fn merge(&mut self, other: &UpdateTracker) {
+	fn merge(&mut self, other: &UpdateTracker) -> bool {
+		let mut changed = false;
 		for (k, v) in other.0.iter() {
 			if let Some(v_mut) = self.0.get_mut(k) {
-				*v_mut = std::cmp::max(*v_mut, *v);
+				if *v > *v_mut {
+					*v_mut = *v;
+					changed = true;
+				}
 			} else {
 				self.0.insert(*k, *v);
+				changed = true;
 			}
 		}
+		changed
 	}
 
 	pub(crate) fn min(&self) -> u64 {
@@ -371,9 +381,10 @@ impl UpdateTracker {
 }
 
 impl UpdateTrackers {
-	pub(crate) fn merge(&mut self, other: &UpdateTrackers) {
+	pub(crate) fn merge(&mut self, other: &UpdateTrackers) -> bool {
-		self.ack_map.merge(&other.ack_map);
+		let c1 = self.ack_map.merge(&other.ack_map);
-		self.sync_map.merge(&other.sync_map);
+		let c2 = self.sync_map.merge(&other.sync_map);
-		self.sync_ack_map.merge(&other.sync_ack_map);
+		let c3 = self.sync_ack_map.merge(&other.sync_ack_map);
+		c1 || c2 || c3
 	}
 }

src/rpc/system.rs

@@ -34,7 +34,7 @@ use crate::consul::ConsulDiscovery;
 #[cfg(feature = "kubernetes-discovery")]
 use crate::kubernetes::*;
 use crate::layout::manager::{LayoutManager, LayoutStatus};
-use crate::layout::*;
+use crate::layout::{self, LayoutHistory, NodeRoleV};
 use crate::replication_mode::*;
 use crate::rpc_helper::*;
 
@@ -65,10 +65,15 @@ pub enum SystemRpc {
 	GetKnownNodes,
 	/// Return known nodes
 	ReturnKnownNodes(Vec<KnownNodeInfo>),
+
 	/// Ask other node its cluster layout. Answered with AdvertiseClusterLayout
 	PullClusterLayout,
 	/// Advertisement of cluster layout. Sent spontanously or in response to PullClusterLayout
 	AdvertiseClusterLayout(LayoutHistory),
+	/// Ask other node its cluster layout update trackers.
+	PullClusterLayoutTrackers,
+	/// Advertisement of cluster layout update trackers.
+	AdvertiseClusterLayoutTrackers(layout::UpdateTrackers),
 }
 
 impl Rpc for SystemRpc {
@@ -727,6 +732,14 @@ impl EndpointHandler<SystemRpc> for System {
 					.handle_advertise_cluster_layout(adv)
 					.await
 			}
+			SystemRpc::PullClusterLayoutTrackers => {
+				Ok(self.layout_manager.handle_pull_cluster_layout_trackers())
+			}
+			SystemRpc::AdvertiseClusterLayoutTrackers(adv) => {
+				self.layout_manager
+					.handle_advertise_cluster_layout_trackers(adv)
+					.await
+			}
 
 			// ---- other -> Error ----
 			m => Err(Error::unexpected_rpc_message(m)),