Merge pull request 'ReplicationMode -> ConsistencyMode+ReplicationFactor' (#750) from yuka/garage:split-consistency-mode into next-0.10

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/750

4 files changed, 33 insertions, 25 deletions

diff --git a/src/rpc/layout/helper.rs b/src/rpc/layout/helper.rs
index 9fb738ea..2835347a 100644
--- a/src/rpc/layout/helper.rs
+++ b/src/rpc/layout/helper.rs
@@ -7,7 +7,7 @@ use serde::{Deserialize, Serialize};
 use garage_util::data::*;
 
 use super::*;
-use crate::replication_mode::ReplicationMode;
+use crate::replication_mode::*;
 
 #[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq, Eq)]
 pub struct RpcLayoutDigest {
@@ -29,7 +29,8 @@ pub struct SyncLayoutDigest {
 }
 
 pub struct LayoutHelper {
-	replication_mode: ReplicationMode,
+	replication_factor: ReplicationFactor,
+	consistency_mode: ConsistencyMode,
 	layout: Option<LayoutHistory>,
 
 	// cached values
@@ -57,7 +58,8 @@ impl Deref for LayoutHelper {
 
 impl LayoutHelper {
 	pub fn new(
-		replication_mode: ReplicationMode,
+		replication_factor: ReplicationFactor,
+		consistency_mode: ConsistencyMode,
 		mut layout: LayoutHistory,
 		mut ack_lock: HashMap<u64, AtomicUsize>,
 	) -> Self {
@@ -66,7 +68,7 @@ impl LayoutHelper {
 		// correct and we have rapid access to important values such as
 		// the layout versions to use when reading to ensure consistency.
 
-		if !replication_mode.is_read_after_write_consistent() {
+		if consistency_mode != ConsistencyMode::Consistent {
 			// Fast path for when no consistency is required.
 			// In this case we only need to keep the last version of the layout,
 			// we don't care about coordinating stuff in the cluster.
@@ -103,7 +105,7 @@ impl LayoutHelper {
 		// This value is calculated using quorums to allow progress even
 		// if not all nodes have successfully completed a sync.
 		let sync_map_min =
-			layout.calculate_sync_map_min_with_quorum(replication_mode, &all_nongateway_nodes);
+			layout.calculate_sync_map_min_with_quorum(replication_factor, &all_nongateway_nodes);
 
 		let trackers_hash = layout.calculate_trackers_hash();
 		let staging_hash = layout.calculate_staging_hash();
@@ -114,7 +116,8 @@ impl LayoutHelper {
 			.or_insert(AtomicUsize::new(0));
 
 		LayoutHelper {
-			replication_mode,
+			replication_factor,
+			consistency_mode,
 			layout: Some(layout),
 			ack_map_min,
 			sync_map_min,
@@ -139,7 +142,8 @@ impl LayoutHelper {
 		let changed = f(self.layout.as_mut().unwrap());
 		if changed {
 			*self = Self::new(
-				self.replication_mode,
+				self.replication_factor,
+				self.consistency_mode,
 				self.layout.take().unwrap(),
 				std::mem::take(&mut self.ack_lock),
 			);
diff --git a/src/rpc/layout/history.rs b/src/rpc/layout/history.rs
index b8cc27da..290f058d 100644
--- a/src/rpc/layout/history.rs
+++ b/src/rpc/layout/history.rs
@@ -6,11 +6,11 @@ use garage_util::encode::nonversioned_encode;
 use garage_util::error::*;
 
 use super::*;
-use crate::replication_mode::ReplicationMode;
+use crate::replication_mode::*;
 
 impl LayoutHistory {
-	pub fn new(replication_factor: usize) -> Self {
-		let version = LayoutVersion::new(replication_factor);
+	pub fn new(replication_factor: ReplicationFactor) -> Self {
+		let version = LayoutVersion::new(replication_factor.into());
 
 		let staging = LayoutStaging {
 			parameters: Lww::<LayoutParameters>::new(version.parameters),
@@ -119,7 +119,7 @@ impl LayoutHistory {
 
 	pub(crate) fn calculate_sync_map_min_with_quorum(
 		&self,
-		replication_mode: ReplicationMode,
+		replication_factor: ReplicationFactor,
 		all_nongateway_nodes: &[Uuid],
 	) -> u64 {
 		// This function calculates the minimum layout version from which
@@ -133,7 +133,7 @@ impl LayoutHistory {
 			return self.current().version;
 		}
 
-		let quorum = replication_mode.write_quorum();
+		let quorum = replication_factor.write_quorum(ConsistencyMode::Consistent);
 
 		let min_version = self.min_stored();
 		let global_min = self
diff --git a/src/rpc/layout/manager.rs b/src/rpc/layout/manager.rs
index 0b6c7e63..8a6eb1c3 100644
--- a/src/rpc/layout/manager.rs
+++ b/src/rpc/layout/manager.rs
@@ -14,13 +14,13 @@ use garage_util::error::*;
 use garage_util::persister::Persister;
 
 use super::*;
-use crate::replication_mode::ReplicationMode;
+use crate::replication_mode::*;
 use crate::rpc_helper::*;
 use crate::system::*;
 
 pub struct LayoutManager {
 	node_id: Uuid,
-	replication_mode: ReplicationMode,
+	replication_factor: ReplicationFactor,
 	persist_cluster_layout: Persister<LayoutHistory>,
 
 	layout: Arc<RwLock<LayoutHelper>>,
@@ -38,20 +38,19 @@ impl LayoutManager {
 		node_id: NodeID,
 		system_endpoint: Arc<Endpoint<SystemRpc, System>>,
 		peering: Arc<PeeringManager>,
-		replication_mode: ReplicationMode,
+		replication_factor: ReplicationFactor,
+		consistency_mode: ConsistencyMode,
 	) -> Result<Arc<Self>, Error> {
-		let replication_factor = replication_mode.replication_factor();
-
 		let persist_cluster_layout: Persister<LayoutHistory> =
 			Persister::new(&config.metadata_dir, "cluster_layout");
 
 		let cluster_layout = match persist_cluster_layout.load() {
 			Ok(x) => {
-				if x.current().replication_factor != replication_mode.replication_factor() {
+				if x.current().replication_factor != replication_factor.replication_factor() {
 					return Err(Error::Message(format!(
 						"Prevous cluster layout has replication factor {}, which is different than the one specified in the config file ({}). The previous cluster layout can be purged, if you know what you are doing, simply by deleting the `cluster_layout` file in your metadata directory.",
 						x.current().replication_factor,
-						replication_factor
+						replication_factor.replication_factor()
 					)));
 				}
 				x
@@ -65,8 +64,12 @@ impl LayoutManager {
 			}
 		};
 
-		let mut cluster_layout =
-			LayoutHelper::new(replication_mode, cluster_layout, Default::default());
+		let mut cluster_layout = LayoutHelper::new(
+			replication_factor,
+			consistency_mode,
+			cluster_layout,
+			Default::default(),
+		);
 		cluster_layout.update_trackers(node_id.into());
 
 		let layout = Arc::new(RwLock::new(cluster_layout));
@@ -81,7 +84,7 @@ impl LayoutManager {
 
 		Ok(Arc::new(Self {
 			node_id: node_id.into(),
-			replication_mode,
+			replication_factor,
 			persist_cluster_layout,
 			layout,
 			change_notify,
@@ -295,11 +298,11 @@ impl LayoutManager {
 			adv.update_trackers
 		);
 
-		if adv.current().replication_factor != self.replication_mode.replication_factor() {
+		if adv.current().replication_factor != self.replication_factor.replication_factor() {
 			let msg = format!(
 				"Received a cluster layout from another node with replication factor {}, which is different from what we have in our configuration ({}). Discarding the cluster layout we received.",
 				adv.current().replication_factor,
-				self.replication_mode.replication_factor()
+				self.replication_factor.replication_factor()
 			);
 			error!("{}", msg);
 			return Err(Error::Message(msg));
diff --git a/src/rpc/layout/test.rs b/src/rpc/layout/test.rs
index 88eb518e..fcbb9dfc 100644
--- a/src/rpc/layout/test.rs
+++ b/src/rpc/layout/test.rs
@@ -5,6 +5,7 @@ use garage_util::crdt::Crdt;
 use garage_util::error::*;
 
 use crate::layout::*;
+use crate::replication_mode::ReplicationFactor;
 
 // This function checks that the partition size S computed is at least better than the
 // one given by a very naive algorithm. To do so, we try to run the naive algorithm
@@ -120,7 +121,7 @@ fn test_assignment() {
 	let mut node_capacity_vec = vec![4000, 1000, 2000];
 	let mut node_zone_vec = vec!["A", "B", "C"];
 
-	let mut cl = LayoutHistory::new(3);
+	let mut cl = LayoutHistory::new(ReplicationFactor::new(3).unwrap());
 	update_layout(&mut cl, &node_capacity_vec, &node_zone_vec, 3);
 	let v = cl.current().version;
 	let (mut cl, msg) = cl.apply_staged_changes(Some(v + 1)).unwrap();