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authorAlex Auvolat <alex@adnab.me>2023-12-07 14:27:53 +0100
committerAlex Auvolat <alex@adnab.me>2023-12-07 14:51:20 +0100
commit9cecea64d4509e95ac9793b29c947e2ecf9bb0b8 (patch)
tree38e9f105004ceea86e064892aab5f20f9c3c4f46 /src/rpc/layout/helper.rs
parentaa59059a910eb6e1e824b84413a66909d697ef8a (diff)
downloadgarage-9cecea64d4509e95ac9793b29c947e2ecf9bb0b8.tar.gz
garage-9cecea64d4509e95ac9793b29c947e2ecf9bb0b8.zip
layout: allow sync update tracker to progress with only quorums
Diffstat (limited to 'src/rpc/layout/helper.rs')
-rw-r--r--src/rpc/layout/helper.rs33
1 files changed, 26 insertions, 7 deletions
diff --git a/src/rpc/layout/helper.rs b/src/rpc/layout/helper.rs
index 0aa7c6aa..eeaf4ffa 100644
--- a/src/rpc/layout/helper.rs
+++ b/src/rpc/layout/helper.rs
@@ -7,6 +7,7 @@ use serde::{Deserialize, Serialize};
use garage_util::data::*;
use super::schema::*;
+use crate::replication_mode::ReplicationMode;
use crate::rpc_helper::RpcHelper;
#[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq, Eq)]
@@ -22,6 +23,7 @@ pub struct LayoutDigest {
}
pub struct LayoutHelper {
+ replication_mode: ReplicationMode,
layout: Option<LayoutHistory>,
// cached values
@@ -48,7 +50,23 @@ impl Deref for LayoutHelper {
}
impl LayoutHelper {
- pub fn new(mut layout: LayoutHistory, mut ack_lock: HashMap<u64, AtomicUsize>) -> Self {
+ pub fn new(
+ replication_mode: ReplicationMode,
+ mut layout: LayoutHistory,
+ mut ack_lock: HashMap<u64, AtomicUsize>,
+ ) -> Self {
+ // In the new() function of the helper, we do a bunch of cleanup
+ // and calculations on the layout history to make sure things are
+ // 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() {
+ // 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.
+ layout.keep_current_version_only();
+ }
+
layout.cleanup_old_versions();
let all_nodes = layout.get_all_nodes();
@@ -68,7 +86,7 @@ impl LayoutHelper {
.ack_map
.min_among(&all_nodes, min_version);
- // sync_map_min is the minimum value of sync_map among all storage nodes
+ // sync_map_min is the minimum value of sync_map among storage nodes
// in the cluster (non-gateway nodes only, current and previous layouts).
// It is the highest layout version for which we know that all relevant
// storage nodes have fullfilled a sync, and therefore it is safe to
@@ -76,11 +94,10 @@ impl LayoutHelper {
// Gateway nodes are excluded here because they hold no relevant data
// (they store the bucket and access key tables, but we don't have
// consistency on those).
- // TODO: this value could take quorums into account instead.
- let sync_map_min = layout
- .update_trackers
- .sync_map
- .min_among(&all_nongateway_nodes, min_version);
+ // 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);
let trackers_hash = layout.calculate_trackers_hash();
let staging_hash = layout.calculate_staging_hash();
@@ -91,6 +108,7 @@ impl LayoutHelper {
.or_insert(AtomicUsize::new(0));
LayoutHelper {
+ replication_mode,
layout: Some(layout),
ack_map_min,
sync_map_min,
@@ -115,6 +133,7 @@ impl LayoutHelper {
let changed = f(&mut self.layout.as_mut().unwrap());
if changed {
*self = Self::new(
+ self.replication_mode,
self.layout.take().unwrap(),
std::mem::take(&mut self.ack_lock),
);