Remove epidemic propagation for fully replicated stuff: write directly to all nodes

src/table/table.rs

@@ -61,9 +61,8 @@ pub trait TableReplication: Send + Sync {
 
 	// Which nodes to send writes to
 	fn write_nodes(&self, hash: &Hash, system: &System) -> Vec<UUID>;
-	fn write_quorum(&self) -> usize;
+	fn write_quorum(&self, system: &System) -> usize;
 	fn max_write_errors(&self) -> usize;
-	fn epidemic_writes(&self) -> bool;
 
 	// Which are the nodes that do actually replicate the data
 	fn replication_nodes(&self, hash: &Hash, ring: &Ring) -> Vec<UUID>;
@@ -119,7 +118,7 @@ where
 			.try_call_many(
 				&who[..],
 				rpc,
-				RequestStrategy::with_quorum(self.replication.write_quorum())
+				RequestStrategy::with_quorum(self.replication.write_quorum(&self.system))
 					.with_timeout(TABLE_RPC_TIMEOUT),
 			)
 			.await?;
@@ -382,7 +381,6 @@ where
 
 	pub async fn handle_update(self: &Arc<Self>, entries: &[Arc<ByteBuf>]) -> Result<(), Error> {
 		let syncer = self.syncer.load_full().unwrap();
-		let mut epidemic_propagate = vec![];
 
 		for update_bytes in entries.iter() {
 			let update = self.decode_entry(update_bytes.as_slice())?;
@@ -410,22 +408,11 @@ where
 			})?;
 
 			if old_entry.as_ref() != Some(&new_entry) {
-				if self.replication.epidemic_writes() {
-					epidemic_propagate.push(new_entry.clone());
-				}
-
 				self.instance.updated(old_entry, Some(new_entry));
 				syncer.invalidate(&tree_key[..]);
 			}
 		}
 
-		if epidemic_propagate.len() > 0 {
-			let self2 = self.clone();
-			self.system
-				.background
-				.spawn_cancellable(async move { self2.insert_many(&epidemic_propagate[..]).await });
-		}
-
 		Ok(())
 	}
 

src/table/table_fullcopy.rs

@@ -1,4 +1,3 @@
-use arc_swap::ArcSwapOption;
 use std::sync::Arc;
 
 use garage_rpc::membership::System;
@@ -9,10 +8,7 @@ use crate::*;
 
 #[derive(Clone)]
 pub struct TableFullReplication {
-	pub write_factor: usize,
-	pub write_quorum: usize,
-
-	neighbors: ArcSwapOption<Neighbors>,
+	pub max_faults: usize,
 }
 
 #[derive(Clone)]
@@ -22,45 +18,8 @@ struct Neighbors {
 }
 
 impl TableFullReplication {
-	pub fn new(write_factor: usize, write_quorum: usize) -> Self {
-		TableFullReplication {
-			write_factor,
-			write_quorum,
-			neighbors: ArcSwapOption::from(None),
-		}
-	}
-
-	fn get_neighbors(&self, system: &System) -> Vec<UUID> {
-		let neighbors = self.neighbors.load_full();
-		if let Some(n) = neighbors {
-			if Arc::ptr_eq(&n.ring, &system.ring.borrow()) {
-				return n.neighbors.clone();
-			}
-		}
-
-		// Recalculate neighbors
-		let ring = system.ring.borrow().clone();
-		let my_id = system.id;
-
-		let mut nodes = vec![];
-		for (node, _) in ring.config.members.iter() {
-			let node_ranking = fasthash(&[node.as_slice(), my_id.as_slice()].concat());
-			nodes.push((*node, node_ranking));
-		}
-		nodes.sort_by(|(_, rank1), (_, rank2)| rank1.cmp(rank2));
-		let mut neighbors = nodes
-			.drain(..)
-			.map(|(node, _)| node)
-			.filter(|node| *node != my_id)
-			.take(self.write_factor)
-			.collect::<Vec<_>>();
-
-		neighbors.push(my_id);
-		self.neighbors.swap(Some(Arc::new(Neighbors {
-			ring,
-			neighbors: neighbors.clone(),
-		})));
-		neighbors
+	pub fn new(max_faults: usize) -> Self {
+		TableFullReplication { max_faults }
 	}
 }
 
@@ -78,17 +37,14 @@ impl TableReplication for TableFullReplication {
 		1
 	}
 
-	fn write_nodes(&self, _hash: &Hash, system: &System) -> Vec<UUID> {
-		self.get_neighbors(system)
+	fn write_nodes(&self, hash: &Hash, system: &System) -> Vec<UUID> {
+		self.replication_nodes(hash, system.ring.borrow().as_ref())
 	}
-	fn write_quorum(&self) -> usize {
-		self.write_quorum
+	fn write_quorum(&self, system: &System) -> usize {
+		system.ring.borrow().config.members.len() - self.max_faults
 	}
 	fn max_write_errors(&self) -> usize {
-		self.write_factor - self.write_quorum
-	}
-	fn epidemic_writes(&self) -> bool {
-		true
+		self.max_faults
 	}
 
 	fn replication_nodes(&self, _hash: &Hash, ring: &Ring) -> Vec<UUID> {

src/table/table_sharded.rs

@@ -31,15 +31,12 @@ impl TableReplication for TableShardedReplication {
 		let ring = system.ring.borrow().clone();
 		ring.walk_ring(&hash, self.replication_factor)
 	}
-	fn write_quorum(&self) -> usize {
+	fn write_quorum(&self, _system: &System) -> usize {
 		self.write_quorum
 	}
 	fn max_write_errors(&self) -> usize {
 		self.replication_factor - self.write_quorum
 	}
-	fn epidemic_writes(&self) -> bool {
-		false
-	}
 
 	fn replication_nodes(&self, hash: &Hash, ring: &Ring) -> Vec<UUID> {
 		ring.walk_ring(&hash, self.replication_factor)

src/table/table_sync.rs

@@ -319,7 +319,13 @@ where
 				}
 
 				counter += 1;
-				debug!("Offloading {} items from {:?}..{:?} ({})", items.len(), begin, end, counter);
+				debug!(
+					"Offloading {} items from {:?}..{:?} ({})",
+					items.len(),
+					begin,
+					end,
+					counter
+				);
 				self.offload_items(&items, &nodes[..]).await?;
 			} else {
 				break;
@@ -408,7 +414,11 @@ where
 						.iter()
 						.all(|x| *x == 0u8)
 				{
-					trace!("range_checksum {:?} returning {} items", range, children.len());
+					trace!(
+						"range_checksum {:?} returning {} items",
+						range,
+						children.len()
+					);
 					return Ok(RangeChecksum {
 						bounds: range.clone(),
 						children,
@@ -423,7 +433,11 @@ where
 				};
 				children.push((item_range, blake2sum(&value[..])));
 			}
-			trace!("range_checksum {:?} returning {} items", range, children.len());
+			trace!(
+				"range_checksum {:?} returning {} items",
+				range,
+				children.len()
+			);
 			Ok(RangeChecksum {
 				bounds: range.clone(),
 				children,
@@ -449,7 +463,11 @@ where
 				}
 
 				if sub_ck.found_limit.is_none() || sub_ck.hash.is_none() {
-					trace!("range_checksum {:?} returning {} items", range, children.len());
+					trace!(
+						"range_checksum {:?} returning {} items",
+						range,
+						children.len()
+					);
 					return Ok(RangeChecksum {
 						bounds: range.clone(),
 						children,
@@ -464,7 +482,11 @@ where
 					.iter()
 					.all(|x| *x == 0u8)
 				{
-					trace!("range_checksum {:?} returning {} items", range, children.len());
+					trace!(
+						"range_checksum {:?} returning {} items",
+						range,
+						children.len()
+					);
 					return Ok(RangeChecksum {
 						bounds: range.clone(),
 						children,