Merge pull request 'NLnet task 3' (#667) from nlnet-task3 into next-0.10

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/667

1 files changed, 116 insertions, 133 deletions

diff --git a/src/table/sync.rs b/src/table/sync.rs
index 92a353c6..cd080df0 100644
--- a/src/table/sync.rs
+++ b/src/table/sync.rs
@@ -6,18 +6,19 @@ use arc_swap::ArcSwapOption;
 use async_trait::async_trait;
 use futures_util::stream::*;
 use opentelemetry::KeyValue;
-use rand::Rng;
+use rand::prelude::*;
 use serde::{Deserialize, Serialize};
 use serde_bytes::ByteBuf;
 use tokio::select;
-use tokio::sync::{mpsc, watch};
+use tokio::sync::{mpsc, watch, Notify};
 
 use garage_util::background::*;
 use garage_util::data::*;
 use garage_util::encode::{debug_serialize, nonversioned_encode};
 use garage_util::error::{Error, OkOrMessage};
 
-use garage_rpc::ring::*;
+use garage_rpc::layout::*;
+use garage_rpc::rpc_helper::QuorumSetResultTracker;
 use garage_rpc::system::System;
 use garage_rpc::*;
 
@@ -52,16 +53,6 @@ impl Rpc for SyncRpc {
 	type Response = Result<SyncRpc, Error>;
 }
 
-#[derive(Debug, Clone)]
-struct TodoPartition {
-	partition: Partition,
-	begin: Hash,
-	end: Hash,
-
-	// Are we a node that stores this partition or not?
-	retain: bool,
-}
-
 impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 	pub(crate) fn new(
 		system: Arc<System>,
@@ -91,10 +82,10 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 
 		bg.spawn_worker(SyncWorker {
 			syncer: self.clone(),
-			ring_recv: self.system.ring.clone(),
-			ring: self.system.ring.borrow().clone(),
+			layout_notify: self.system.layout_notify(),
+			layout_digest: self.system.cluster_layout().sync_digest(),
 			add_full_sync_rx,
-			todo: vec![],
+			todo: None,
 			next_full_sync: Instant::now() + Duration::from_secs(20),
 		});
 	}
@@ -112,53 +103,56 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 
 	async fn sync_partition(
 		self: &Arc<Self>,
-		partition: &TodoPartition,
+		partition: &SyncPartition,
 		must_exit: &mut watch::Receiver<bool>,
 	) -> Result<(), Error> {
-		if partition.retain {
-			let my_id = self.system.id;
-
-			let nodes = self
-				.data
-				.replication
-				.write_nodes(&partition.begin)
-				.into_iter()
-				.filter(|node| *node != my_id)
-				.collect::<Vec<_>>();
+		let my_id = self.system.id;
+		let retain = partition.storage_sets.iter().any(|x| x.contains(&my_id));
 
+		if retain {
 			debug!(
 				"({}) Syncing {:?} with {:?}...",
 				F::TABLE_NAME,
 				partition,
-				nodes
+				partition.storage_sets
 			);
-			let mut sync_futures = nodes
-				.iter()
+			let mut result_tracker = QuorumSetResultTracker::new(
+				&partition.storage_sets,
+				self.data.replication.write_quorum(),
+			);
+
+			let mut sync_futures = result_tracker
+				.nodes
+				.keys()
+				.copied()
 				.map(|node| {
-					self.clone()
-						.do_sync_with(partition.clone(), *node, must_exit.clone())
+					let must_exit = must_exit.clone();
+					async move {
+						if node == my_id {
+							(node, Ok(()))
+						} else {
+							(node, self.do_sync_with(partition, node, must_exit).await)
+						}
+					}
 				})
 				.collect::<FuturesUnordered<_>>();
 
-			let mut n_errors = 0;
-			while let Some(r) = sync_futures.next().await {
-				if let Err(e) = r {
-					n_errors += 1;
-					warn!("({}) Sync error: {}", F::TABLE_NAME, e);
+			while let Some((node, res)) = sync_futures.next().await {
+				if let Err(e) = &res {
+					warn!("({}) Sync error with {:?}: {}", F::TABLE_NAME, node, e);
 				}
+				result_tracker.register_result(node, res);
 			}
-			if n_errors > self.data.replication.max_write_errors() {
-				return Err(Error::Message(format!(
-					"Sync failed with too many nodes (should have been: {:?}).",
-					nodes
-				)));
+
+			if result_tracker.too_many_failures() {
+				Err(result_tracker.quorum_error())
+			} else {
+				Ok(())
 			}
 		} else {
-			self.offload_partition(&partition.begin, &partition.end, must_exit)
-				.await?;
+			self.offload_partition(&partition.first_hash, &partition.last_hash, must_exit)
+				.await
 		}
-
-		Ok(())
 	}
 
 	// Offload partition: this partition is not something we are storing,
@@ -188,12 +182,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 			}
 
 			if !items.is_empty() {
-				let nodes = self
-					.data
-					.replication
-					.write_nodes(begin)
-					.into_iter()
-					.collect::<Vec<_>>();
+				let nodes = self.data.replication.storage_nodes(begin);
 				if nodes.contains(&self.system.id) {
 					warn!(
 						"({}) Interrupting offload as partitions seem to have changed",
@@ -217,7 +206,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 					end,
 					counter
 				);
-				self.offload_items(&items, &nodes[..]).await?;
+				self.offload_items(&items, &nodes).await?;
 			} else {
 				break;
 			}
@@ -244,7 +233,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 		}
 
 		self.system
-			.rpc
+			.rpc_helper()
 			.try_call_many(
 				&self.endpoint,
 				nodes,
@@ -284,8 +273,8 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 	}
 
 	async fn do_sync_with(
-		self: Arc<Self>,
-		partition: TodoPartition,
+		self: &Arc<Self>,
+		partition: &SyncPartition,
 		who: Uuid,
 		must_exit: watch::Receiver<bool>,
 	) -> Result<(), Error> {
@@ -305,7 +294,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 		// If so, do nothing.
 		let root_resp = self
 			.system
-			.rpc
+			.rpc_helper()
 			.call(
 				&self.endpoint,
 				who,
@@ -361,7 +350,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 					// and compare it with local node
 					let remote_node = match self
 						.system
-						.rpc
+						.rpc_helper()
 						.call(
 							&self.endpoint,
 							who,
@@ -437,7 +426,7 @@ impl<F: TableSchema, R: TableReplication> TableSyncer<F, R> {
 
 		let rpc_resp = self
 			.system
-			.rpc
+			.rpc_helper()
 			.call(
 				&self.endpoint,
 				who,
@@ -492,75 +481,41 @@ impl<F: TableSchema, R: TableReplication> EndpointHandler<SyncRpc> for TableSync
 
 struct SyncWorker<F: TableSchema, R: TableReplication> {
 	syncer: Arc<TableSyncer<F, R>>,
-	ring_recv: watch::Receiver<Arc<Ring>>,
-	ring: Arc<Ring>,
+
+	layout_notify: Arc<Notify>,
+	layout_digest: SyncLayoutDigest,
+
 	add_full_sync_rx: mpsc::UnboundedReceiver<()>,
-	todo: Vec<TodoPartition>,
 	next_full_sync: Instant,
+
+	todo: Option<SyncPartitions>,
 }
 
 impl<F: TableSchema, R: TableReplication> SyncWorker<F, R> {
-	fn add_full_sync(&mut self) {
-		let system = &self.syncer.system;
-		let data = &self.syncer.data;
-
-		let my_id = system.id;
-
-		self.todo.clear();
-
-		let partitions = data.replication.partitions();
-
-		for i in 0..partitions.len() {
-			let begin = partitions[i].1;
-
-			let end = if i + 1 < partitions.len() {
-				partitions[i + 1].1
-			} else {
-				[0xFFu8; 32].into()
-			};
-
-			let nodes = data.replication.write_nodes(&begin);
-
-			let retain = nodes.contains(&my_id);
-			if !retain {
-				// Check if we have some data to send, otherwise skip
-				match data.store.range(begin..end) {
-					Ok(mut iter) => {
-						if iter.next().is_none() {
-							continue;
-						}
-					}
-					Err(e) => {
-						warn!("DB error in add_full_sync: {}", e);
-						continue;
-					}
-				}
-			}
-
-			self.todo.push(TodoPartition {
-				partition: partitions[i].0,
-				begin,
-				end,
-				retain,
-			});
+	fn check_add_full_sync(&mut self) {
+		let layout_digest = self.syncer.system.cluster_layout().sync_digest();
+		if layout_digest != self.layout_digest {
+			self.layout_digest = layout_digest;
+			info!(
+				"({}) Layout versions changed ({:?}), adding full sync to syncer todo list",
+				F::TABLE_NAME,
+				layout_digest,
+			);
+			self.add_full_sync();
 		}
-
-		self.next_full_sync = Instant::now() + ANTI_ENTROPY_INTERVAL;
 	}
 
-	fn pop_task(&mut self) -> Option<TodoPartition> {
-		if self.todo.is_empty() {
-			return None;
-		}
+	fn add_full_sync(&mut self) {
+		let mut partitions = self.syncer.data.replication.sync_partitions();
+		info!(
+			"{}: Adding full sync for ack layout version {}",
+			F::TABLE_NAME,
+			partitions.layout_version
+		);
 
-		let i = rand::thread_rng().gen_range(0..self.todo.len());
-		if i == self.todo.len() - 1 {
-			self.todo.pop()
-		} else {
-			let replacement = self.todo.pop().unwrap();
-			let ret = std::mem::replace(&mut self.todo[i], replacement);
-			Some(ret)
-		}
+		partitions.partitions.shuffle(&mut thread_rng());
+		self.todo = Some(partitions);
+		self.next_full_sync = Instant::now() + ANTI_ENTROPY_INTERVAL;
 	}
 }
 
@@ -572,14 +527,48 @@ impl<F: TableSchema, R: TableReplication> Worker for SyncWorker<F, R> {
 
 	fn status(&self) -> WorkerStatus {
 		WorkerStatus {
-			queue_length: Some(self.todo.len() as u64),
+			queue_length: Some(self.todo.as_ref().map(|x| x.partitions.len()).unwrap_or(0) as u64),
 			..Default::default()
 		}
 	}
 
 	async fn work(&mut self, must_exit: &mut watch::Receiver<bool>) -> Result<WorkerState, Error> {
-		if let Some(partition) = self.pop_task() {
-			self.syncer.sync_partition(&partition, must_exit).await?;
+		self.check_add_full_sync();
+
+		if let Some(todo) = &mut self.todo {
+			let partition = todo.partitions.pop().unwrap();
+
+			// process partition
+			if let Err(e) = self.syncer.sync_partition(&partition, must_exit).await {
+				error!(
+					"{}: Failed to sync partition {:?}: {}",
+					F::TABLE_NAME,
+					partition,
+					e
+				);
+				// if error, put partition back at the other side of the queue,
+				// so that other partitions will be tried in the meantime
+				todo.partitions.insert(0, partition);
+				// TODO: returning an error here will cause the background job worker
+				// to delay this task for some time, but maybe we don't want to
+				// delay it if there are lots of failures from nodes that are gone
+				// (we also don't want zero delays as that will cause lots of useless retries)
+				return Err(e);
+			}
+
+			if todo.partitions.is_empty() {
+				info!(
+					"{}: Completed full sync for ack layout version {}",
+					F::TABLE_NAME,
+					todo.layout_version
+				);
+				self.syncer
+					.system
+					.layout_manager
+					.sync_table_until(F::TABLE_NAME, todo.layout_version);
+				self.todo = None;
+			}
+
 			Ok(WorkerState::Busy)
 		} else {
 			Ok(WorkerState::Idle)
@@ -593,22 +582,16 @@ impl<F: TableSchema, R: TableReplication> Worker for SyncWorker<F, R> {
 					self.add_full_sync();
 				}
 			},
-			_ = self.ring_recv.changed() => {
-				let new_ring = self.ring_recv.borrow();
-				if !Arc::ptr_eq(&new_ring, &self.ring) {
-					self.ring = new_ring.clone();
-					drop(new_ring);
-					debug!("({}) Ring changed, adding full sync to syncer todo list", F::TABLE_NAME);
-					self.add_full_sync();
-				}
+			_ = self.layout_notify.notified() => {
+				self.check_add_full_sync();
 			},
 			_ = tokio::time::sleep_until(self.next_full_sync.into()) => {
 				self.add_full_sync();
 			}
 		}
-		match self.todo.is_empty() {
-			false => WorkerState::Busy,
-			true => WorkerState::Idle,
+		match self.todo.is_some() {
+			true => WorkerState::Busy,
+			false => WorkerState::Idle,
 		}
 	}
 }