Merge pull request 'Some improvements to Garage internals' (#451) from internals-rework into main

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/451

2 files changed, 37 insertions, 51 deletions

diff --git a/src/rpc/rpc_helper.rs b/src/rpc/rpc_helper.rs
index 949aced6..1ec250c3 100644
--- a/src/rpc/rpc_helper.rs
+++ b/src/rpc/rpc_helper.rs
@@ -5,7 +5,6 @@ use std::time::Duration;
 use futures::future::join_all;
 use futures::stream::futures_unordered::FuturesUnordered;
 use futures::stream::StreamExt;
-use futures_util::future::FutureExt;
 use tokio::select;
 use tokio::sync::watch;
 
@@ -24,7 +23,6 @@ pub use netapp::message::{
 use netapp::peering::fullmesh::FullMeshPeeringStrategy;
 pub use netapp::{self, NetApp, NodeID};
 
-use garage_util::background::BackgroundRunner;
 use garage_util::data::*;
 use garage_util::error::Error;
 use garage_util::metrics::RecordDuration;
@@ -94,7 +92,6 @@ pub struct RpcHelper(Arc<RpcHelperInner>);
 struct RpcHelperInner {
 	our_node_id: Uuid,
 	fullmesh: Arc<FullMeshPeeringStrategy>,
-	background: Arc<BackgroundRunner>,
 	ring: watch::Receiver<Arc<Ring>>,
 	metrics: RpcMetrics,
 	rpc_timeout: Duration,
@@ -104,7 +101,6 @@ impl RpcHelper {
 	pub(crate) fn new(
 		our_node_id: Uuid,
 		fullmesh: Arc<FullMeshPeeringStrategy>,
-		background: Arc<BackgroundRunner>,
 		ring: watch::Receiver<Arc<Ring>>,
 		rpc_timeout: Option<Duration>,
 	) -> Self {
@@ -113,7 +109,6 @@ impl RpcHelper {
 		Self(Arc::new(RpcHelperInner {
 			our_node_id,
 			fullmesh,
-			background,
 			ring,
 			metrics,
 			rpc_timeout: rpc_timeout.unwrap_or(DEFAULT_TIMEOUT),
@@ -377,16 +372,13 @@ impl RpcHelper {
 
 			if !resp_stream.is_empty() {
 				// Continue remaining requests in background.
-				// Continue the remaining requests immediately using tokio::spawn
-				// but enqueue a task in the background runner
-				// to ensure that the process won't exit until the requests are done
-				// (if we had just enqueued the resp_stream.collect directly in the background runner,
-				// the requests might have been put on hold in the background runner's queue,
-				// in which case they might timeout or otherwise fail)
-				let wait_finished_fut = tokio::spawn(async move {
+				// Note: these requests can get interrupted on process shutdown,
+				// we must not count on them being executed for certain.
+				// For all background things that have to happen with certainty,
+				// they have to be put in a proper queue that is persisted to disk.
+				tokio::spawn(async move {
 					resp_stream.collect::<Vec<Result<_, _>>>().await;
 				});
-				self.0.background.spawn(wait_finished_fut.map(|_| Ok(())));
 			}
 		}
 
diff --git a/src/rpc/system.rs b/src/rpc/system.rs
index 2c6f14fd..8f753b7f 100644
--- a/src/rpc/system.rs
+++ b/src/rpc/system.rs
@@ -21,7 +21,6 @@ use netapp::peering::fullmesh::FullMeshPeeringStrategy;
 use netapp::util::parse_and_resolve_peer_addr_async;
 use netapp::{NetApp, NetworkKey, NodeID, NodeKey};
 
-use garage_util::background::BackgroundRunner;
 use garage_util::config::Config;
 #[cfg(feature = "kubernetes-discovery")]
 use garage_util::config::KubernetesDiscoveryConfig;
@@ -50,8 +49,6 @@ pub const GARAGE_VERSION_TAG: u64 = 0x6761726167650008; // garage 0x0008
 /// RPC endpoint used for calls related to membership
 pub const SYSTEM_RPC_PATH: &str = "garage_rpc/membership.rs/SystemRpc";
 
-pub const CONNECT_ERROR_MESSAGE: &str = "Error establishing RPC connection to remote node. This can happen if the remote node is not reachable on the network, but also if the two nodes are not configured with the same rpc_secret";
-
 /// RPC messages related to membership
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub enum SystemRpc {
@@ -110,9 +107,6 @@ pub struct System {
 	pub ring: watch::Receiver<Arc<Ring>>,
 	update_ring: Mutex<watch::Sender<Arc<Ring>>>,
 
-	/// The job runner of this node
-	pub background: Arc<BackgroundRunner>,
-
 	/// Path to metadata directory
 	pub metadata_dir: PathBuf,
 }
@@ -232,7 +226,6 @@ impl System {
 	/// Create this node's membership manager
 	pub fn new(
 		network_key: NetworkKey,
-		background: Arc<BackgroundRunner>,
 		replication_mode: ReplicationMode,
 		config: &Config,
 	) -> Result<Arc<Self>, Error> {
@@ -354,7 +347,6 @@ impl System {
 			rpc: RpcHelper::new(
 				netapp.id.into(),
 				fullmesh,
-				background.clone(),
 				ring.clone(),
 				config.rpc_timeout_msec.map(Duration::from_millis),
 			),
@@ -372,7 +364,6 @@ impl System {
 
 			ring,
 			update_ring: Mutex::new(update_ring),
-			background,
 			metadata_dir: config.metadata_dir.clone(),
 		});
 		sys.system_endpoint.set_handler(sys.clone());
@@ -444,17 +435,14 @@ impl System {
 				))
 			})?;
 		let mut errors = vec![];
-		for ip in addrs.iter() {
-			match self
-				.netapp
-				.clone()
-				.try_connect(*ip, pubkey)
-				.await
-				.err_context(CONNECT_ERROR_MESSAGE)
-			{
+		for addr in addrs.iter() {
+			match self.netapp.clone().try_connect(*addr, pubkey).await {
 				Ok(()) => return Ok(()),
 				Err(e) => {
-					errors.push((*ip, e));
+					errors.push((
+						*addr,
+						Error::Message(connect_error_message(*addr, pubkey, e)),
+					));
 				}
 			}
 		}
@@ -578,7 +566,7 @@ impl System {
 	}
 
 	/// Save network configuration to disc
-	async fn save_cluster_layout(self: Arc<Self>) -> Result<(), Error> {
+	async fn save_cluster_layout(&self) -> Result<(), Error> {
 		let ring: Arc<Ring> = self.ring.borrow().clone();
 		self.persist_cluster_layout
 			.save_async(&ring.layout)
@@ -630,11 +618,7 @@ impl System {
 		if info.cluster_layout_version > local_info.cluster_layout_version
 			|| info.cluster_layout_staging_hash != local_info.cluster_layout_staging_hash
 		{
-			let self2 = self.clone();
-			self.background.spawn_cancellable(async move {
-				self2.pull_cluster_layout(from).await;
-				Ok(())
-			});
+			tokio::spawn(self.clone().pull_cluster_layout(from));
 		}
 
 		self.node_status
@@ -676,18 +660,21 @@ impl System {
 			drop(update_ring);
 
 			let self2 = self.clone();
-			self.background.spawn_cancellable(async move {
-				self2
+			tokio::spawn(async move {
+				if let Err(e) = self2
 					.rpc
 					.broadcast(
 						&self2.system_endpoint,
 						SystemRpc::AdvertiseClusterLayout(layout),
 						RequestStrategy::with_priority(PRIO_HIGH),
 					)
-					.await?;
-				Ok(())
+					.await
+				{
+					warn!("Error while broadcasting new cluster layout: {}", e);
+				}
 			});
-			self.background.spawn(self.clone().save_cluster_layout());
+
+			self.save_cluster_layout().await?;
 		}
 
 		Ok(SystemRpc::Ok)
@@ -773,12 +760,12 @@ impl System {
 				}
 
 				for (node_id, node_addr) in ping_list {
-					tokio::spawn(
-						self.netapp
-							.clone()
-							.try_connect(node_addr, node_id)
-							.map(|r| r.err_context(CONNECT_ERROR_MESSAGE)),
-					);
+					let self2 = self.clone();
+					tokio::spawn(async move {
+						if let Err(e) = self2.netapp.clone().try_connect(node_addr, node_id).await {
+							error!("{}", connect_error_message(node_addr, node_id, e));
+						}
+					});
 				}
 			}
 
@@ -787,11 +774,10 @@ impl System {
 			}
 
 			#[cfg(feature = "consul-discovery")]
-			self.background.spawn(self.clone().advertise_to_consul());
+			background::spawn(self.clone().advertise_to_consul());
 
 			#[cfg(feature = "kubernetes-discovery")]
-			self.background
-				.spawn(self.clone().advertise_to_kubernetes());
+			background::spawn(self.clone().advertise_to_kubernetes());
 
 			let restart_at = tokio::time::sleep(DISCOVERY_INTERVAL);
 			select! {
@@ -881,3 +867,11 @@ async fn resolve_peers(peers: &[String]) -> Vec<(NodeID, SocketAddr)> {
 
 	ret
 }
+
+fn connect_error_message(
+	addr: SocketAddr,
+	pubkey: ed25519::PublicKey,
+	e: netapp::error::Error,
+) -> String {
+	format!("Error establishing RPC connection to remote node: {}@{}.\nThis can happen if the remote node is not reachable on the network, but also if the two nodes are not configured with the same rpc_secret.\n{}", hex::encode(pubkey), addr, e)
+}