From 9d95f6f7040c1899715ae4f984313427b1432758 Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Thu, 9 Nov 2023 15:52:45 +0100
Subject: [PATCH] layout: fix tracker bugs

---
 src/rpc/layout/manager.rs | 8 +++++++-
 src/rpc/layout/schema.rs  | 6 +++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/rpc/layout/manager.rs b/src/rpc/layout/manager.rs
index ffcc938b..c1417dac 100644
--- a/src/rpc/layout/manager.rs
+++ b/src/rpc/layout/manager.rs
@@ -125,10 +125,10 @@ impl LayoutManager {
 
 		if !prev_layout_check || adv.check().is_ok() {
 			if layout.merge(adv) {
+				layout.update_trackers(self.node_id);
 				if prev_layout_check && layout.check().is_err() {
 					panic!("Merged two correct layouts and got an incorrect layout.");
 				}
-				layout.update_trackers(self.node_id);
 				return Some(layout.clone());
 			}
 		}
@@ -245,6 +245,8 @@ impl LayoutManager {
 		self: &Arc<Self>,
 		adv: &LayoutHistory,
 	) -> Result<SystemRpc, Error> {
+		debug!("handle_advertise_cluster_layout: {:?}", adv);
+
 		if adv.current().replication_factor != self.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.",
@@ -256,6 +258,8 @@ impl LayoutManager {
 		}
 
 		if let Some(new_layout) = self.merge_layout(adv) {
+			debug!("handle_advertise_cluster_layout: some changes were added to the current stuff");
+
 			self.change_notify.notify_waiters();
 			self.broadcast_update(SystemRpc::AdvertiseClusterLayout(new_layout));
 			self.save_cluster_layout().await?;
@@ -268,6 +272,8 @@ impl LayoutManager {
 		self: &Arc<Self>,
 		trackers: &UpdateTrackers,
 	) -> Result<SystemRpc, Error> {
+		debug!("handle_advertise_cluster_layout_trackers: {:?}", trackers);
+
 		if let Some(new_trackers) = self.merge_layout_trackers(trackers) {
 			self.change_notify.notify_waiters();
 			self.broadcast_update(SystemRpc::AdvertiseClusterLayoutTrackers(new_trackers));
diff --git a/src/rpc/layout/schema.rs b/src/rpc/layout/schema.rs
index 9f5d6f62..db60c806 100644
--- a/src/rpc/layout/schema.rs
+++ b/src/rpc/layout/schema.rs
@@ -190,7 +190,7 @@ mod v010 {
 	use garage_util::crdt::{Lww, LwwMap};
 	use garage_util::data::{Hash, Uuid};
 	use serde::{Deserialize, Serialize};
-	use std::collections::HashMap;
+	use std::collections::BTreeMap;
 	pub use v09::{LayoutParameters, NodeRole, NodeRoleV, ZoneRedundancy};
 
 	/// The layout of the cluster, i.e. the list of roles
@@ -257,7 +257,7 @@ mod v010 {
 
 	/// The history of cluster layouts
 	#[derive(Clone, Debug, Serialize, Deserialize, Default, PartialEq)]
-	pub struct UpdateTracker(pub HashMap<Uuid, u64>);
+	pub struct UpdateTracker(pub BTreeMap<Uuid, u64>);
 
 	impl garage_util::migrate::Migrate for LayoutHistory {
 		const VERSION_MARKER: &'static [u8] = b"G010lh";
@@ -278,7 +278,7 @@ mod v010 {
 				version
 					.nongateway_nodes()
 					.map(|x| (x, version.version))
-					.collect::<HashMap<Uuid, u64>>(),
+					.collect::<BTreeMap<Uuid, u64>>(),
 			);
 			let staging = LayoutStaging {
 				parameters: previous.staging_parameters,