layout: more refactoring

src/garage/cli/layout.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use bytesize::ByteSize;
 
 use format_table::format_table;
@@ -321,7 +323,7 @@ pub async fn fetch_layout(
 		.call(&rpc_host, SystemRpc::PullClusterLayout, PRIO_NORMAL)
 		.await??
 	{
-		SystemRpc::AdvertiseClusterLayout(t) => Ok(t),
+		SystemRpc::AdvertiseClusterLayout(t) => Ok(Arc::try_unwrap(t).unwrap()),
 		resp => Err(Error::Message(format!("Invalid RPC response: {:?}", resp))),
 	}
 }
@@ -334,7 +336,7 @@ pub async fn send_layout(
 	rpc_cli
 		.call(
 			&rpc_host,
-			SystemRpc::AdvertiseClusterLayout(layout),
+			SystemRpc::AdvertiseClusterLayout(Arc::new(layout)),
 			PRIO_NORMAL,
 		)
 		.await??;

src/rpc/layout/manager.rs

@@ -1,6 +1,8 @@
 use std::sync::Arc;
 use std::time::Duration;
 
+use serde::{Deserialize, Serialize};
+
 use tokio::sync::watch;
 use tokio::sync::Mutex;
 
@@ -28,6 +30,16 @@ pub struct LayoutManager {
 	system_endpoint: Arc<Endpoint<SystemRpc, System>>,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct LayoutStatus {
+	/// Cluster layout version
+	pub cluster_layout_version: u64,
+	/// Hash of cluster layout update trackers
+	// (TODO) pub cluster_layout_trackers_hash: Hash,
+	/// Hash of cluster layout staging data
+	pub cluster_layout_staging_hash: Hash,
+}
+
 impl LayoutManager {
 	pub fn new(
 		config: &Config,
@@ -35,7 +47,7 @@ impl LayoutManager {
 		system_endpoint: Arc<Endpoint<SystemRpc, System>>,
 		fullmesh: Arc<FullMeshPeeringStrategy>,
 		replication_factor: usize,
-	) -> Result<Self, Error> {
+	) -> Result<Arc<Self>, Error> {
 		let persist_cluster_layout: Persister<LayoutHistory> =
 			Persister::new(&config.metadata_dir, "cluster_layout");
 
@@ -68,28 +80,39 @@ impl LayoutManager {
 			config.rpc_timeout_msec.map(Duration::from_millis),
 		);
 
-		Ok(Self {
+		Ok(Arc::new(Self {
 			replication_factor,
 			persist_cluster_layout,
 			layout_watch,
 			update_layout: Mutex::new(update_layout),
 			system_endpoint,
 			rpc_helper,
-		})
+		}))
 	}
 
 	// ---- PUBLIC INTERFACE ----
 
-	pub async fn update_cluster_layout(&self, layout: &LayoutHistory) -> Result<(), Error> {
+	pub fn status(&self) -> LayoutStatus {
+		let layout = self.layout();
+		LayoutStatus {
+			cluster_layout_version: layout.current().version,
+			cluster_layout_staging_hash: layout.staging_hash,
+		}
+	}
+
+	pub async fn update_cluster_layout(
+		self: &Arc<Self>,
+		layout: &LayoutHistory,
+	) -> Result<(), Error> {
 		self.handle_advertise_cluster_layout(layout).await?;
 		Ok(())
 	}
 
-	pub fn history(&self) -> watch::Ref<Arc<LayoutHistory>> {
+	pub fn layout(&self) -> watch::Ref<Arc<LayoutHistory>> {
 		self.layout_watch.borrow()
 	}
 
-	pub(crate) async fn pull_cluster_layout(&self, peer: Uuid) {
+	pub(crate) async fn pull_cluster_layout(self: &Arc<Self>, peer: Uuid) {
 		let resp = self
 			.rpc_helper
 			.call(
@@ -118,13 +141,25 @@ impl LayoutManager {
 
 	// ---- RPC HANDLERS ----
 
+	pub(crate) fn handle_advertise_status(self: &Arc<Self>, from: Uuid, status: &LayoutStatus) {
+		let local_status = self.status();
+		if status.cluster_layout_version > local_status.cluster_layout_version
+			|| status.cluster_layout_staging_hash != local_status.cluster_layout_staging_hash
+		{
+			tokio::spawn({
+				let this = self.clone();
+				async move { this.pull_cluster_layout(from).await }
+			});
+		}
+	}
+
 	pub(crate) fn handle_pull_cluster_layout(&self) -> SystemRpc {
-		let layout = self.layout_watch.borrow().as_ref().clone();
+		let layout = self.layout_watch.borrow().clone();
 		SystemRpc::AdvertiseClusterLayout(layout)
 	}
 
 	pub(crate) async fn handle_advertise_cluster_layout(
-		&self,
+		self: &Arc<Self>,
 		adv: &LayoutHistory,
 	) -> Result<SystemRpc, Error> {
 		if adv.current().replication_factor != self.replication_factor {
@@ -137,8 +172,8 @@ impl LayoutManager {
 			return Err(Error::Message(msg));
 		}
 
+		if *adv != **self.layout_watch.borrow() {
 			let update_layout = self.update_layout.lock().await;
-		// TODO: don't clone each time an AdvertiseClusterLayout is received
 			let mut layout: LayoutHistory = self.layout_watch.borrow().as_ref().clone();
 
 			let prev_layout_check = layout.check().is_ok();
@@ -150,15 +185,17 @@ impl LayoutManager {
 					));
 				}
 
-			update_layout.send(Arc::new(layout.clone()))?;
-			drop(update_layout);
+				let layout = Arc::new(layout);
+				update_layout.send(layout.clone())?;
+				drop(update_layout); // release mutex
 
-			/* TODO
-			tokio::spawn(async move {
-				if let Err(e) = system
-					.rpc_helper()
+				tokio::spawn({
+					let this = self.clone();
+					async move {
+						if let Err(e) = this
+							.rpc_helper
 							.broadcast(
-						&system.system_endpoint,
+								&this.system_endpoint,
 								SystemRpc::AdvertiseClusterLayout(layout),
 								RequestStrategy::with_priority(PRIO_HIGH),
 							)
@@ -166,11 +203,12 @@ impl LayoutManager {
 						{
 							warn!("Error while broadcasting new cluster layout: {}", e);
 						}
+					}
 				});
-			*/
 
 				self.save_cluster_layout().await?;
 			}
+		}
 
 		Ok(SystemRpc::Ok)
 	}

src/rpc/layout/schema.rs

@@ -226,7 +226,7 @@ mod v010 {
 	}
 
 	/// The history of cluster layouts
-	#[derive(Clone, Debug, Serialize, Deserialize)]
+	#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 	pub struct LayoutHistory {
 		/// The versions currently in use in the cluster
 		pub versions: Vec<LayoutVersion>,
@@ -241,7 +241,7 @@ mod v010 {
 	}
 
 	/// The tracker of acknowlegments and data syncs around the cluster
-	#[derive(Clone, Debug, Serialize, Deserialize, Default)]
+	#[derive(Clone, Debug, Serialize, Deserialize, Default, PartialEq)]
 	pub struct UpdateTrackers {
 		/// The highest layout version number each node has ack'ed
 		pub ack_map: UpdateTracker,
@@ -253,7 +253,7 @@ mod v010 {
 	}
 
 	/// The history of cluster layouts
-	#[derive(Clone, Debug, Serialize, Deserialize, Default)]
+	#[derive(Clone, Debug, Serialize, Deserialize, Default, PartialEq)]
 	pub struct UpdateTracker(pub HashMap<Uuid, u64>);
 
 	impl garage_util::migrate::Migrate for LayoutHistory {

src/rpc/system.rs

@@ -33,7 +33,7 @@ use garage_util::time::*;
 use crate::consul::ConsulDiscovery;
 #[cfg(feature = "kubernetes-discovery")]
 use crate::kubernetes::*;
-use crate::layout::manager::LayoutManager;
+use crate::layout::manager::{LayoutManager, LayoutStatus};
 use crate::layout::*;
 use crate::replication_mode::*;
 use crate::rpc_helper::*;
@@ -68,7 +68,7 @@ pub enum SystemRpc {
 	/// Ask other node its cluster layout. Answered with AdvertiseClusterLayout
 	PullClusterLayout,
 	/// Advertisement of cluster layout. Sent spontanously or in response to PullClusterLayout
-	AdvertiseClusterLayout(LayoutHistory),
+	AdvertiseClusterLayout(Arc<LayoutHistory>),
 }
 
 impl Rpc for SystemRpc {
@@ -104,7 +104,7 @@ pub struct System {
 	#[cfg(feature = "kubernetes-discovery")]
 	kubernetes_discovery: Option<KubernetesDiscoveryConfig>,
 
-	pub layout_manager: LayoutManager,
+	pub layout_manager: Arc<LayoutManager>,
 
 	metrics: SystemMetrics,
 
@@ -125,12 +125,8 @@ pub struct NodeStatus {
 	/// Replication factor configured on the node
 	pub replication_factor: usize,
 
-	/// Cluster layout version
-	pub cluster_layout_version: u64,
-	/// Hash of cluster layout update trackers
-	// (TODO) pub cluster_layout_trackers_hash: Hash,
-	/// Hash of cluster layout staging data
-	pub cluster_layout_staging_hash: Hash,
+	/// Layout status
+	pub layout_status: LayoutStatus,
 
 	/// Disk usage on partition containing metadata directory (tuple: `(avail, total)`)
 	#[serde(default)]
@@ -284,7 +280,7 @@ impl System {
 		// ---- set up metrics and status exchange ----
 		let metrics = SystemMetrics::new(replication_factor);
 
-		let mut local_status = NodeStatus::initial(replication_factor, &layout_manager.history());
+		let mut local_status = NodeStatus::initial(replication_factor, &layout_manager);
 		local_status.update_disk_usage(&config.metadata_dir, &config.data_dir, &metrics);
 
 		// ---- if enabled, set up additionnal peer discovery methods ----
@@ -350,7 +346,7 @@ impl System {
 	// ---- Public utilities / accessors ----
 
 	pub fn cluster_layout(&self) -> watch::Ref<Arc<LayoutHistory>> {
-		self.layout_manager.history()
+		self.layout_manager.layout()
 	}
 
 	pub fn layout_watch(&self) -> watch::Receiver<Arc<LayoutHistory>> {
@@ -536,9 +532,7 @@ impl System {
 	fn update_local_status(&self) {
 		let mut new_si: NodeStatus = self.local_status.load().as_ref().clone();
 
-		let layout = self.cluster_layout();
-		new_si.cluster_layout_version = layout.current().version;
-		new_si.cluster_layout_staging_hash = layout.staging_hash;
+		new_si.layout_status = self.layout_manager.status();
 
 		new_si.update_disk_usage(&self.metadata_dir, &self.data_dir, &self.metrics);
 
@@ -571,14 +565,8 @@ impl System {
 			std::process::exit(1);
 		}
 
-		if info.cluster_layout_version > local_info.cluster_layout_version
-			|| info.cluster_layout_staging_hash != local_info.cluster_layout_staging_hash
-		{
-			tokio::spawn({
-				let system = self.clone();
-				async move { system.layout_manager.pull_cluster_layout(from).await }
-			});
-		}
+		self.layout_manager
+			.handle_advertise_status(from, &info.layout_status);
 
 		self.node_status
 			.write()
@@ -746,14 +734,13 @@ impl EndpointHandler<SystemRpc> for System {
 }
 
 impl NodeStatus {
-	fn initial(replication_factor: usize, layout: &LayoutHistory) -> Self {
+	fn initial(replication_factor: usize, layout_manager: &LayoutManager) -> Self {
 		NodeStatus {
 			hostname: gethostname::gethostname()
 				.into_string()
 				.unwrap_or_else(|_| "<invalid utf-8>".to_string()),
 			replication_factor,
-			cluster_layout_version: layout.current().version,
-			cluster_layout_staging_hash: layout.staging_hash,
+			layout_status: layout_manager.status(),
 			meta_disk_avail: None,
 			data_disk_avail: None,
 		}
@@ -763,8 +750,7 @@ impl NodeStatus {
 		NodeStatus {
 			hostname: "?".to_string(),
 			replication_factor: 0,
-			cluster_layout_version: 0,
-			cluster_layout_staging_hash: Hash::from([0u8; 32]),
+			layout_status: Default::default(),
 			meta_disk_avail: None,
 			data_disk_avail: None,
 		}