test(e2e): fail incomplete conditional PUT races

crates/common/src/mrf_channel.rs

@@ -23,32 +23,21 @@
 //! unconsumed intents is the consumer's job (see `rustfs-heal`
 //! `heal::mrf_queue`), mirroring MinIO's `.heal/mrf/list.bin`.
 
-use std::collections::HashMap;
-use std::collections::hash_map::RandomState;
-use std::hash::{BuildHasher, Hash};
-use std::sync::atomic::AtomicU64;
-use std::sync::atomic::AtomicUsize;
 use std::sync::{
-    Arc, Mutex, OnceLock,
+    Arc, OnceLock,
     atomic::{AtomicBool, Ordering},
 };
-use std::time::{Duration, Instant};
 use tokio::sync::mpsc;
 use uuid::Uuid;
 
 /// Bounded capacity of the global MRF channel. Backpressure is resolved by
 /// dropping (and counting) intents, never by blocking the producer.
 const MRF_CHANNEL_CAPACITY: usize = 8192;
-const MRF_COALESCER_SHARDS: usize = 16;
-const MRF_COALESCER_MAX_KEYS: usize = 8192;
-const MRF_COALESCER_MAX_BYTES: usize = 16 * 1024 * 1024;
-const MRF_COALESCER_TTL: Duration = Duration::from_secs(60);
-const MRF_MAX_IDENTITY_COMPONENT: usize = 1024;
 
 /// Why an intent was produced. Drives the heal priority mapping on the
 /// consumer side (DecodeFailure -> Urgent, MetadataCorruption -> High,
 /// PartialWrite -> Normal).
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum MrfKind {
     /// Erasure decode failed while serving a read (read path).
     DecodeFailure,
@@ -78,52 +67,12 @@ pub struct MrfIntent {
     /// Version the intent targets, as raw UUID bytes.
     pub version_id: Option<[u8; 16]>,
     pub kind: MrfKind,
-    /// Stable erasure-set scope when the producer has it. Kept optional so
-    /// metadata corruption and legacy producers do not invent a scope.
-    pub scope: Option<MrfScope>,
-    /// Generation of the node-local ingress lease. It is not persisted in
-    /// the journal; replayed records acquire a fresh lease when re-enqueued.
-    pub lease: Option<MrfIngressLease>,
     pub enqueued_at_ms: u64,
     /// Times this intent has already been offered to the heal manager.
     /// Dropped by the consumer once it reaches `MRF_MAX_ATTEMPTS`.
     pub attempts: u8,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct MrfScope {
-    pub pool_index: u32,
-    pub set_index: u32,
-}
-
-/// Opaque generation used to release exactly the admission that created an
-/// ingress entry. A generation prevents a late terminal callback from
-/// deleting a newer retry for the same identity (ABA).
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct MrfIngressLease(u64);
-
-impl MrfIngressLease {
-    const fn new(value: u64) -> Self {
-        Self(value)
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum MrfDropReason {
-    Disabled,
-    Uninitialized,
-    Full,
-    OversizedIdentity,
-    CoalescerFull,
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum MrfIngressResult {
-    Enqueued,
-    Coalesced,
-    Dropped(MrfDropReason),
-}
-
 /// Consumer-side retry ceiling before an intent is given up on.
 pub const MRF_MAX_ATTEMPTS: u8 = 3;
 
@@ -138,159 +87,6 @@ impl MrfIntent {
 
 static GLOBAL_MRF_SENDER: OnceLock<mpsc::Sender<MrfIntent>> = OnceLock::new();
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-struct MrfIdentityKey {
-    kind: MrfKind,
-    bucket: Arc<str>,
-    object: Arc<str>,
-    version_id: Option<[u8; 16]>,
-    scope: Option<MrfScope>,
-}
-
-#[derive(Debug)]
-struct IngressEntry {
-    lease: MrfIngressLease,
-    expires_at: Instant,
-    bytes: usize,
-}
-
-type MrfCoalescerShard = Mutex<HashMap<MrfIdentityKey, IngressEntry>>;
-type MrfCoalescer = Box<[MrfCoalescerShard]>;
-
-static MRF_COALESCER: OnceLock<MrfCoalescer> = OnceLock::new();
-static NEXT_MRF_LEASE: AtomicU64 = AtomicU64::new(1);
-static MRF_COALESCER_COUNT: AtomicUsize = AtomicUsize::new(0);
-static MRF_COALESCER_BYTES: AtomicUsize = AtomicUsize::new(0);
-static MRF_HASH_STATE: OnceLock<RandomState> = OnceLock::new();
-
-fn coalescer() -> &'static [MrfCoalescerShard] {
-    MRF_COALESCER.get_or_init(|| {
-        (0..MRF_COALESCER_SHARDS)
-            .map(|_| Mutex::new(HashMap::new()))
-            .collect::<Vec<_>>()
-            .into_boxed_slice()
-    })
-}
-
-fn key_shard(key: &MrfIdentityKey) -> usize {
-    let hash = MRF_HASH_STATE.get_or_init(RandomState::new).hash_one(key);
-    usize::try_from(hash).unwrap_or(0) % MRF_COALESCER_SHARDS
-}
-
-fn canonical_version(version_id: Option<Uuid>) -> Option<[u8; 16]> {
-    version_id
-        .filter(|version| !version.is_nil())
-        .map(|version| *version.as_bytes())
-}
-
-fn canonical_identity(
-    kind: MrfKind,
-    version_id: Option<[u8; 16]>,
-    scope: Option<MrfScope>,
-) -> (Option<[u8; 16]>, Option<MrfScope>) {
-    let version_id = version_id.filter(|bytes| *bytes != [0; 16]);
-    match kind {
-        MrfKind::MetadataCorruption => (None, None),
-        MrfKind::DecodeFailure | MrfKind::PartialWrite => (version_id, scope),
-    }
-}
-
-fn identity_estimated_bytes(key: &MrfIdentityKey) -> usize {
-    64usize
-        .saturating_add(key.bucket.len())
-        .saturating_add(key.object.len())
-        .saturating_add(key.version_id.map_or(0, |_| 16))
-        .saturating_add(key.scope.map_or(0, |_| 8))
-}
-
-fn reserve(counter: &AtomicUsize, limit: usize, amount: usize) -> bool {
-    let mut current = counter.load(Ordering::Relaxed);
-    loop {
-        let Some(next) = current.checked_add(amount) else {
-            return false;
-        };
-        if next > limit {
-            return false;
-        }
-        match counter.compare_exchange_weak(current, next, Ordering::Relaxed, Ordering::Relaxed) {
-            Ok(_) => return true,
-            Err(observed) => current = observed,
-        }
-    }
-}
-
-fn coalescer_admit(key: MrfIdentityKey) -> Result<MrfIngressLease, MrfIngressResult> {
-    let shard = key_shard(&key);
-    let mut entries = coalescer()[shard]
-        .lock()
-        .map_err(|_| MrfIngressResult::Dropped(MrfDropReason::CoalescerFull))?;
-    let now = Instant::now();
-    let before = entries.len();
-    let mut expired_bytes = 0usize;
-    entries.retain(|_, entry| {
-        if entry.expires_at > now {
-            true
-        } else {
-            expired_bytes = expired_bytes.saturating_add(entry.bytes);
-            false
-        }
-    });
-    let evicted = before.saturating_sub(entries.len());
-    if evicted > 0 {
-        MRF_COALESCER_COUNT.fetch_sub(evicted, Ordering::Relaxed);
-        MRF_COALESCER_BYTES.fetch_sub(expired_bytes, Ordering::Relaxed);
-        let evicted = u64::try_from(evicted).unwrap_or(u64::MAX);
-        metrics::counter!("rustfs_heal_mrf_coalescer_expired_total").increment(evicted);
-        metrics::counter!("rustfs_heal_mrf_coalescer_evictions_total").increment(evicted);
-    }
-    if entries.contains_key(&key) {
-        metrics::counter!("rustfs_heal_mrf_coalesced_total").increment(1);
-        return Err(MrfIngressResult::Coalesced);
-    }
-    let bytes = identity_estimated_bytes(&key);
-    let count_reserved = reserve(&MRF_COALESCER_COUNT, MRF_COALESCER_MAX_KEYS, 1);
-    let bytes_reserved = count_reserved && reserve(&MRF_COALESCER_BYTES, MRF_COALESCER_MAX_BYTES, bytes);
-    if !count_reserved || !bytes_reserved {
-        if count_reserved {
-            MRF_COALESCER_COUNT.fetch_sub(1, Ordering::Relaxed);
-        }
-        metrics::counter!("rustfs_heal_mrf_dropped_total", "reason" => "coalescer_full").increment(1);
-        return Err(MrfIngressResult::Dropped(MrfDropReason::CoalescerFull));
-    }
-    let lease = MrfIngressLease::new(NEXT_MRF_LEASE.fetch_add(1, Ordering::Relaxed));
-    if entries
-        .insert(
-            key,
-            IngressEntry {
-                lease,
-                expires_at: now + MRF_COALESCER_TTL,
-                bytes,
-            },
-        )
-        .is_some()
-    {
-        MRF_COALESCER_COUNT.fetch_sub(1, Ordering::Relaxed);
-        MRF_COALESCER_BYTES.fetch_sub(bytes, Ordering::Relaxed);
-        metrics::counter!("rustfs_heal_mrf_coalesced_total").increment(1);
-        return Err(MrfIngressResult::Coalesced);
-    }
-    Ok(lease)
-}
-
-fn coalescer_release(key: &MrfIdentityKey, lease: Option<MrfIngressLease>) {
-    let Some(lease) = lease else {
-        return;
-    };
-    if let Ok(mut entries) = coalescer()[key_shard(key)].lock() {
-        let should_remove = entries.get(key).is_some_and(|entry| entry.lease == lease);
-        if should_remove {
-            let bytes = entries.remove(key).map(|entry| entry.bytes).unwrap_or(0);
-            MRF_COALESCER_COUNT.fetch_sub(1, Ordering::Relaxed);
-            MRF_COALESCER_BYTES.fetch_sub(bytes, Ordering::Relaxed);
-        }
-    }
-}
-
 /// Delivery kill-switch, set from `RUSTFS_HEAL_MRF_ENABLE`. Producers check
 /// this before touching the channel so the disabled path stays allocation- and
 /// sync-free.
@@ -326,90 +122,21 @@ pub fn init_mrf_channel() -> Result<mpsc::Receiver<MrfIntent>, &'static str> {
 /// This runs on IO error paths, so it stays synchronous and cheap: one
 /// bounded allocation for the two `Arc<str>` handles plus the channel slot.
 pub fn try_send_mrf_intent(kind: MrfKind, bucket: &str, object: &str, version_id: Option<Uuid>) -> bool {
-    matches!(
-        try_send_mrf_intent_typed(kind, bucket, object, version_id, None),
-        MrfIngressResult::Enqueued
-    )
-}
-
-/// Typed ingress result. `Coalesced` means an equivalent in-flight channel
-/// intent already exists; it is not a second executable or durable admission.
-pub fn try_send_mrf_intent_typed(
-    kind: MrfKind,
-    bucket: &str,
-    object: &str,
-    version_id: Option<Uuid>,
-    scope: Option<MrfScope>,
-) -> MrfIngressResult {
     if !mrf_delivery_enabled() {
-        return MrfIngressResult::Dropped(MrfDropReason::Disabled);
+        return false;
     }
     let Some(sender) = GLOBAL_MRF_SENDER.get() else {
-        return MrfIngressResult::Dropped(MrfDropReason::Uninitialized);
-    };
-    if bucket.len() > MRF_MAX_IDENTITY_COMPONENT || object.len() > MRF_MAX_IDENTITY_COMPONENT {
-        return MrfIngressResult::Dropped(MrfDropReason::OversizedIdentity);
-    }
-    let (version_id, scope) = canonical_identity(kind, canonical_version(version_id), scope);
-    let key = MrfIdentityKey {
-        kind,
-        bucket: Arc::from(bucket),
-        object: Arc::from(object),
-        version_id,
-        scope,
-    };
-    let lease = match coalescer_admit(key.clone()) {
-        Ok(lease) => lease,
-        Err(result) => return result,
+        return false;
     };
     let intent = MrfIntent {
-        bucket: key.bucket.clone(),
-        object: key.object.clone(),
-        version_id: key.version_id,
+        bucket: Arc::from(bucket),
+        object: Arc::from(object),
+        version_id: version_id.map(|vid| *vid.as_bytes()),
         kind,
-        scope,
-        lease: Some(lease),
         enqueued_at_ms: unix_now_ms(),
         attempts: 0,
     };
-    match sender.try_send(intent) {
-        Ok(()) => MrfIngressResult::Enqueued,
-        Err(mpsc::error::TrySendError::Full(_)) => {
-            coalescer_release(&key, Some(lease));
-            metrics::counter!("rustfs_heal_mrf_dropped_total", "reason" => "channel_full").increment(1);
-            MrfIngressResult::Dropped(MrfDropReason::Full)
-        }
-        Err(mpsc::error::TrySendError::Closed(_)) => {
-            coalescer_release(&key, Some(lease));
-            MrfIngressResult::Dropped(MrfDropReason::Uninitialized)
-        }
-    }
-}
-
-/// Release the ingress key once the consumer owns the intent.
-pub fn release_mrf_intent(intent: &MrfIntent) {
-    release_mrf_identity(intent.kind, &intent.bucket, &intent.object, intent.version_id, intent.scope, intent.lease);
-}
-
-pub fn release_mrf_identity(
-    kind: MrfKind,
-    bucket: &str,
-    object: &str,
-    version_id: Option<[u8; 16]>,
-    scope: Option<MrfScope>,
-    lease: Option<MrfIngressLease>,
-) {
-    let (version_id, scope) = canonical_identity(kind, version_id, scope);
-    coalescer_release(
-        &MrfIdentityKey {
-            kind,
-            bucket: Arc::from(bucket),
-            object: Arc::from(object),
-            version_id,
-            scope,
-        },
-        lease,
-    );
+    sender.try_send(intent).is_ok()
 }
 
 fn unix_now_ms() -> u64 {
@@ -417,8 +144,7 @@ fn unix_now_ms() -> u64 {
     // failure would be a bug rather than something to handle here.
     std::time::SystemTime::now()
         .duration_since(std::time::UNIX_EPOCH)
-        .ok()
-        .and_then(|d| u64::try_from(d.as_millis()).ok())
+        .map(|d| d.as_millis() as u64)
         .unwrap_or(0)
 }
 
@@ -489,60 +215,12 @@ mod tests {
             object: Arc::from("object"),
             version_id: Some([0u8; 16]),
             kind: MrfKind::DecodeFailure,
-            scope: None,
-            lease: None,
             enqueued_at_ms: 0,
             attempts: 0,
         };
         assert!(intent.estimated_bytes() >= intent.bucket.len() + intent.object.len());
     }
 
-    #[test]
-    fn ingress_duplicate_identity_coalesces_and_releases_for_retry() {
-        let key = MrfIdentityKey {
-            kind: MrfKind::DecodeFailure,
-            bucket: Arc::from("ingress-test-bucket"),
-            object: Arc::from("ingress-test-object"),
-            version_id: Some([9; 16]),
-            scope: Some(MrfScope {
-                pool_index: 3,
-                set_index: 4,
-            }),
-        };
-        let lease = coalescer_admit(key.clone()).expect("first identity should be admitted");
-        for _ in 0..999 {
-            assert_eq!(coalescer_admit(key.clone()), Err(MrfIngressResult::Coalesced));
-        }
-        coalescer_release(&key, Some(lease));
-        let retry_lease = coalescer_admit(key.clone()).expect("released identity must admit a retry");
-        coalescer_release(&key, Some(retry_lease));
-    }
-
-    #[test]
-    fn ingress_identity_preserves_kind_scope_and_version_boundaries() {
-        let (nil_version, nil_scope) = canonical_identity(
-            MrfKind::DecodeFailure,
-            Some([0; 16]),
-            Some(MrfScope {
-                pool_index: 1,
-                set_index: 2,
-            }),
-        );
-        assert_eq!(nil_version, None, "nil UUID is the unversioned identity");
-        assert!(nil_scope.is_some());
-
-        let (metadata_version, metadata_scope) = canonical_identity(
-            MrfKind::MetadataCorruption,
-            Some([7; 16]),
-            Some(MrfScope {
-                pool_index: 1,
-                set_index: 2,
-            }),
-        );
-        assert_eq!(metadata_version, None);
-        assert_eq!(metadata_scope, None);
-    }
-
     #[tokio::test]
     async fn try_send_delivers_and_respects_capacity() {
         let mut receiver = init_mrf_channel().expect("first initialization should succeed");
@@ -552,7 +230,6 @@ mod tests {
         let intent = receiver.recv().await.expect("intent should arrive");
         assert_eq!(intent.kind, MrfKind::DecodeFailure);
         assert_eq!(intent.bucket.as_ref(), "b");
-        release_mrf_intent(&intent);
 
         // Disable delivery: producers become no-ops.
         set_mrf_delivery_enabled(false);
@@ -562,8 +239,8 @@ mod tests {
         // Fill the bounded channel past capacity: excess intents are dropped,
         // never blocking.
         let mut accepted = 0;
-        for index in 0..(MRF_CHANNEL_CAPACITY + 64) {
-            if try_send_mrf_intent(MrfKind::PartialWrite, "b", &format!("o-{index}"), None) {
+        for _ in 0..(MRF_CHANNEL_CAPACITY + 64) {
+            if try_send_mrf_intent(MrfKind::PartialWrite, "b", "o", None) {
                 accepted += 1;
             }
         }

crates/e2e_test/src/cluster_concurrency_test.rs

@@ -22,10 +22,9 @@ use tracing::{info, warn};
 
 const BUCKET: &str = "conditional-put-race-bucket";
 
-async fn cleanup_object(client: &Client, key: &str) {
-    if let Err(e) = client.delete_object().bucket(BUCKET).key(key).send().await {
-        warn!("Failed to delete object '{}' from bucket '{}' during cleanup: {:?}", key, BUCKET, e);
-    }
+async fn cleanup_object(client: &Client, key: &str) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    client.delete_object().bucket(BUCKET).key(key).send().await?;
+    Ok(())
 }
 
 async fn conditional_put(
@@ -71,14 +70,13 @@ async fn run_race_iteration(
     test_key: &str,
     iteration: usize,
 ) -> Result<usize, Box<dyn std::error::Error + Send + Sync>> {
-    cleanup_object(&clients[0], test_key).await;
+    cleanup_object(&clients[0], test_key).await?;
     tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
 
-    let head_result = clients[0].head_object().bucket(BUCKET).key(test_key).send().await;
-
-    if head_result.is_ok() {
-        warn!("Warning: Object still exists after cleanup, skipping iteration {}", iteration);
-        return Ok(0);
+    match clients[0].head_object().bucket(BUCKET).key(test_key).send().await {
+        Ok(_) => return Err(format!("object still exists after cleanup in iteration {iteration}").into()),
+        Err(error) if error.as_service_error().is_some_and(|error| error.is_not_found()) => {}
+        Err(error) => return Err(format!("failed to verify cleanup in iteration {iteration}: {error:?}").into()),
     }
 
     info!("\n=== Iteration {} ===", iteration);
@@ -120,14 +118,16 @@ async fn run_race_iteration(
 
     info!("Result: {} out of {} succeeded", success_count, clients.len());
 
+    if had_error {
+        return Err("one or more conditional PUTs failed unexpectedly".into());
+    }
+
     if success_count > 1 {
         info!(">>> RACE CONDITION DETECTED!");
     } else if success_count == 1 {
         info!(">>> Correct behavior: exactly 1 writer succeeded.");
-    } else if had_error {
-        return Err("all conditional PUTs failed (e.g. cluster/bucket not ready)".into());
     } else {
-        info!(">>> Unexpected: no writers succeeded.");
+        return Err("no conditional PUT succeeded".into());
     }
 
     Ok(success_count)
@@ -167,7 +167,7 @@ async fn test_conditional_put_race_cluster() -> Result<(), Box<dyn std::error::E
             }
         }
 
-        cleanup_object(&clients[0], &test_key).await;
+        cleanup_object(&clients[0], &test_key).await?;
         tokio::time::sleep(tokio::time::Duration::from_millis(50)).await;
     }
 
@@ -177,7 +177,7 @@ async fn test_conditional_put_race_cluster() -> Result<(), Box<dyn std::error::E
     info!("Total iterations:   {}", iterations);
     info!("Correct (1 winner): {}", correct_count);
     info!("Race conditions:    {}", races_detected);
-    info!("Errors (skipped):   {}", error_count);
+    info!("Failed iterations:  {}", error_count);
 
     assert_eq!(races_detected, 0, "Race conditions detected: {}/{}", races_detected, iterations);
     assert_eq!(
@@ -185,6 +185,10 @@ async fn test_conditional_put_race_cluster() -> Result<(), Box<dyn std::error::E
         "{} iteration(s) failed due to errors (e.g. cluster not ready)",
         error_count
     );
+    assert_eq!(
+        correct_count, iterations,
+        "only {correct_count}/{iterations} iterations observed exactly one winner"
+    );
 
     Ok(())
 }
@@ -201,7 +205,7 @@ async fn test_conditional_put_basic_cluster() -> Result<(), Box<dyn std::error::
 
     let client = cluster.create_s3_client(0)?;
     let test_key = "basic-conditional-put";
-    cleanup_object(&client, test_key).await;
+    cleanup_object(&client, test_key).await?;
 
     let result = client
         .put_object()
@@ -233,6 +237,6 @@ async fn test_conditional_put_basic_cluster() -> Result<(), Box<dyn std::error::
         assert_eq!(code, "PreconditionFailed");
     }
 
-    cleanup_object(&client, test_key).await;
+    cleanup_object(&client, test_key).await?;
     Ok(())
 }

crates/ecstore/src/set_disk/core/io_primitives.rs

@@ -1412,11 +1412,8 @@ pub(in crate::set_disk) async fn submit_read_repair_heal_with_submitter(
 
     // Reservation won: this sighting owns the repair records for the object,
     // including the durable journal intent when the caller asked for one.
-    if let Some((kind, version_uuid)) = mrf_intent
-        && let (Ok(pool_index), Ok(set_index)) = (u32::try_from(pool_index), u32::try_from(set_index))
-    {
-        let scope = rustfs_common::mrf_channel::MrfScope { pool_index, set_index };
-        let _ = rustfs_common::mrf_channel::try_send_mrf_intent_typed(kind, bucket, object, version_uuid, Some(scope));
+    if let Some((kind, version_uuid)) = mrf_intent {
+        rustfs_common::mrf_channel::try_send_mrf_intent(kind, bucket, object, version_uuid);
     }
 
     let mut request = rustfs_common::heal_channel::create_heal_request_with_options(

crates/ecstore/src/set_disk/ops/object.rs

@@ -6650,23 +6650,12 @@ impl crate::storage_api_contracts::object::ObjectOperations for SetDisks {
     async fn add_partial(&self, bucket: &str, object: &str, version_id: &str) -> Result<()> {
         // MRF journal intent: partial-write recovery must survive a restart
         // (HS-01); the heal request below remains the in-memory fast path.
-        let version_uuid = if version_id.is_empty() {
-            Some(None)
-        } else {
-            uuid::Uuid::try_parse(version_id).ok().map(Some)
-        };
-        if let Some(version_uuid) = version_uuid
-            && let (Ok(pool_index), Ok(set_index)) = (u32::try_from(self.pool_index), u32::try_from(self.set_index))
-        {
-            let scope = rustfs_common::mrf_channel::MrfScope { pool_index, set_index };
-            let _ = rustfs_common::mrf_channel::try_send_mrf_intent_typed(
-                rustfs_common::mrf_channel::MrfKind::PartialWrite,
-                bucket,
-                object,
-                version_uuid,
-                Some(scope),
-            );
-        }
+        rustfs_common::mrf_channel::try_send_mrf_intent(
+            rustfs_common::mrf_channel::MrfKind::PartialWrite,
+            bucket,
+            object,
+            uuid::Uuid::try_parse(version_id).ok(),
+        );
         let mut request = rustfs_common::heal_channel::create_heal_request_with_options(
             bucket.to_string(),
             Some(object.to_string()),

crates/heal/src/heal/manager.rs

@@ -119,9 +119,6 @@ struct MrfRepairNoticeTarget {
     bucket: Arc<str>,
     object: Arc<str>,
     version_id: Option<[u8; 16]>,
-    kind: rustfs_common::mrf_channel::MrfKind,
-    scope: Option<rustfs_common::mrf_channel::MrfScope>,
-    lease: Option<rustfs_common::mrf_channel::MrfIngressLease>,
 }
 
 #[derive(Debug, Clone)]
@@ -892,19 +889,7 @@ impl HealManager {
     }
 
     fn remove_mrf_repair_notice_targets_for_task(&self, task_id: &str) {
-        let targets = lock_mrf_repair_notice_targets(&self.mrf_repair_notice_targets).remove(task_id);
-        if let Some(targets) = targets {
-            for target in targets {
-                rustfs_common::mrf_channel::release_mrf_identity(
-                    target.kind,
-                    &target.bucket,
-                    &target.object,
-                    target.version_id,
-                    target.scope,
-                    target.lease,
-                );
-            }
-        }
+        lock_mrf_repair_notice_targets(&self.mrf_repair_notice_targets).remove(task_id);
     }
 
     fn insert_mrf_repair_notice_target(
@@ -1294,20 +1279,7 @@ impl HealManager {
         }
         self.task_aliases.lock().await.clear();
         self.retrying_heals.lock().await.clear();
-        let mrf_targets = {
-            let mut registry = lock_mrf_repair_notice_targets(&self.mrf_repair_notice_targets);
-            registry.drain().flat_map(|(_, targets)| targets).collect::<Vec<_>>()
-        };
-        for target in mrf_targets {
-            rustfs_common::mrf_channel::release_mrf_identity(
-                target.kind,
-                &target.bucket,
-                &target.object,
-                target.version_id,
-                target.scope,
-                target.lease,
-            );
-        }
+        lock_mrf_repair_notice_targets(&self.mrf_repair_notice_targets).clear();
         crate::set_heal_queue_length(0);
 
         // update state
@@ -1339,32 +1311,12 @@ impl HealManager {
             .await
     }
 
-    #[cfg(test)]
     pub(crate) async fn submit_mrf_heal_request_with_receipt(
         &self,
         request: HealRequest,
         bucket: Arc<str>,
         object: Arc<str>,
         version_id: Option<[u8; 16]>,
-    ) -> Result<HealAdmissionReceipt> {
-        let kind = match &request.heal_type {
-            HealType::Metadata { .. } => rustfs_common::mrf_channel::MrfKind::MetadataCorruption,
-            HealType::ECDecode { .. } => rustfs_common::mrf_channel::MrfKind::DecodeFailure,
-            _ => rustfs_common::mrf_channel::MrfKind::PartialWrite,
-        };
-        self.submit_mrf_heal_request_with_receipt_and_identity(request, bucket, object, version_id, kind, None, None)
-            .await
-    }
-
-    pub(crate) async fn submit_mrf_heal_request_with_receipt_and_identity(
-        &self,
-        request: HealRequest,
-        bucket: Arc<str>,
-        object: Arc<str>,
-        version_id: Option<[u8; 16]>,
-        kind: rustfs_common::mrf_channel::MrfKind,
-        scope: Option<rustfs_common::mrf_channel::MrfScope>,
-        lease: Option<rustfs_common::mrf_channel::MrfIngressLease>,
     ) -> Result<HealAdmissionReceipt> {
         self.submit_heal_request_with_receipt_alias_and_mrf_notice(
             request,
@@ -1373,9 +1325,6 @@ impl HealManager {
                 bucket,
                 object,
                 version_id,
-                kind,
-                scope,
-                lease,
             }),
         )
         .await
@@ -1590,7 +1539,7 @@ impl HealManager {
             Self::insert_mrf_repair_notice_target(&mut targets, &task_id, target);
         }
         if let Some(displaced_task_id) = &displaced_task_id {
-            self.remove_mrf_repair_notice_targets_for_task(displaced_task_id);
+            lock_mrf_repair_notice_targets(&self.mrf_repair_notice_targets).remove(displaced_task_id);
         }
         drop(retrying_heals);
         drop(queue);

crates/heal/src/heal/manager/auto_scan.rs

@@ -506,18 +506,7 @@ impl HealManager {
                                     &displaced_terminal,
                                 )
                                 .await;
-                                if let Some(targets) = lock_mrf_repair_notice_targets(&mrf_repair_notice_targets).remove(&displaced_task_id) {
-                                    for target in targets {
-                                        rustfs_common::mrf_channel::release_mrf_identity(
-                                            target.kind,
-                                            &target.bucket,
-                                            &target.object,
-                                            target.version_id,
-                                            target.scope,
-                                            target.lease,
-                                        );
-                                    }
-                                }
+                                lock_mrf_repair_notice_targets(&mrf_repair_notice_targets).remove(&displaced_task_id);
                             }
                             if matches!(admission, HealAdmissionResult::Accepted) {
                                 if should_notify {

crates/heal/src/heal/manager/queue.rs

@@ -299,11 +299,7 @@ impl PriorityHealQueue {
 
     /// Create a deduplication key from a heal request
     pub(super) fn make_dedup_key(request: &HealRequest) -> String {
-        let base = Self::make_dedup_key_for_type(&request.heal_type);
-        match (&request.heal_type, request.options.set_key()) {
-            (HealType::Object { .. } | HealType::ECDecode { .. }, Some(scope)) => format!("{base}:scope:{scope}"),
-            _ => base,
-        }
+        Self::make_dedup_key_for_type(&request.heal_type)
     }
 
     pub(super) fn make_dedup_key_for_type(heal_type: &HealType) -> String {

crates/heal/src/heal/manager/scheduler.rs

@@ -349,8 +349,6 @@ impl HealManager {
                             let notice_targets = take_mrf_repair_notice_targets(&mrf_repair_notice_targets_clone, &task_id);
                             if successful_completion {
                                 emit_mrf_repaired_events(notice_targets);
-                            } else {
-                                release_mrf_repair_notice_targets(notice_targets);
                             }
                             task_aliases_clone
                                 .lock()
@@ -640,19 +638,7 @@ pub(super) fn running_heal_set_counts(active_heals: &HashMap<String, Arc<HealTas
 }
 
 fn remove_mrf_repair_notice_targets(registry: &Arc<StdMutex<HashMap<String, Vec<MrfRepairNoticeTarget>>>>, task_id: &str) {
-    let targets = lock_mrf_repair_notice_targets(registry).remove(task_id);
-    if let Some(targets) = targets {
-        for target in targets {
-            rustfs_common::mrf_channel::release_mrf_identity(
-                target.kind,
-                &target.bucket,
-                &target.object,
-                target.version_id,
-                target.scope,
-                target.lease,
-            );
-        }
-    }
+    lock_mrf_repair_notice_targets(registry).remove(task_id);
 }
 
 fn take_mrf_repair_notice_targets(
@@ -685,27 +671,6 @@ fn move_mrf_repair_notice_targets(
 fn emit_mrf_repaired_events(targets: Vec<MrfRepairNoticeTarget>) {
     for target in targets {
         rustfs_common::mrf_channel::note_mrf_repaired(&target.bucket, &target.object, target.version_id);
-        rustfs_common::mrf_channel::release_mrf_identity(
-            target.kind,
-            &target.bucket,
-            &target.object,
-            target.version_id,
-            target.scope,
-            target.lease,
-        );
-    }
-}
-
-fn release_mrf_repair_notice_targets(targets: Vec<MrfRepairNoticeTarget>) {
-    for target in targets {
-        rustfs_common::mrf_channel::release_mrf_identity(
-            target.kind,
-            &target.bucket,
-            &target.object,
-            target.version_id,
-            target.scope,
-            target.lease,
-        );
     }
 }
 

crates/heal/src/heal/mrf_queue.rs

@@ -37,7 +37,7 @@ use crate::heal::manager::HealManager;
 use metrics::{counter, gauge};
 use rustfs_common::heal_channel::{HealAdmissionDropReason, HealAdmissionResult};
 use rustfs_common::mrf_channel::{MRF_MAX_ATTEMPTS, MrfIntent};
-use std::collections::{HashSet, VecDeque};
+use std::collections::VecDeque;
 use std::sync::Arc;
 use std::time::Duration;
 use tokio::sync::mpsc;
@@ -48,27 +48,15 @@ use crate::heal::task::{HealOptions, HealPriority, HealRequest, HealType};
 /// Journal location inside the metadata bucket, following the resume-state
 /// layout.
 pub(crate) const MRF_JOURNAL_PATH: &str = "buckets/.heal/mrf/journal.bin";
-/// The scoped path is the authoritative snapshot for new readers and carries
-/// both v1 and v2 records. The legacy path is only a v1 compatibility mirror;
-/// older readers ignore the authoritative path, while new readers never merge
-/// the two files. This prevents a partial two-file flush from fabricating a
-/// mixed epoch.
-pub(crate) const MRF_SCOPED_JOURNAL_PATH: &str = "buckets/.heal/mrf/journal-scoped.bin";
 
 /// Record format tag.
 const MRF_JOURNAL_FORMAT: u8 = 1;
 /// Record layout version.
 const MRF_JOURNAL_VERSION: u8 = 1;
-const MRF_JOURNAL_VERSION_SCOPED: u8 = 2;
 
 /// Fixed header size: format, version, kind, attempts, enqueued_at_ms,
 /// has_version flag.
 const MRF_RECORD_FIXED_HEAD: usize = 1 + 1 + 1 + 1 + 8 + 1;
-const MRF_MAX_IDENTITY_COMPONENT: usize = 1024;
-
-fn metric_f64(value: usize) -> f64 {
-    f64::from(u32::try_from(value).unwrap_or(u32::MAX))
-}
 
 #[derive(Debug, Clone)]
 pub(crate) struct MrfConsumerConfig {
@@ -113,90 +101,40 @@ impl Default for MrfConsumerConfig {
 /// incoming intent (never a resident one) and counts the loss.
 pub(crate) struct MrfQueue {
     pending: VecDeque<MrfIntent>,
-    pending_keys: HashSet<MrfQueueKey>,
     bytes: usize,
     capacity: usize,
     byte_budget: usize,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-struct MrfQueueKey {
-    kind: rustfs_common::mrf_channel::MrfKind,
-    bucket: Arc<str>,
-    object: Arc<str>,
-    version_id: Option<[u8; 16]>,
-    scope: Option<rustfs_common::mrf_channel::MrfScope>,
-}
-
-fn queue_key(intent: &MrfIntent) -> MrfQueueKey {
-    let version_id = intent.version_id.filter(|bytes| *bytes != [0; 16]);
-    let scope = (!matches!(intent.kind, rustfs_common::mrf_channel::MrfKind::MetadataCorruption))
-        .then_some(intent.scope)
-        .flatten();
-    MrfQueueKey {
-        kind: intent.kind,
-        bucket: intent.bucket.clone(),
-        object: intent.object.clone(),
-        version_id,
-        scope,
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub(crate) enum MrfQueuePushResult {
-    Enqueued,
-    Coalesced,
-    Rejected,
-}
-
 impl MrfQueue {
     pub(crate) fn new(capacity: usize, byte_budget: usize) -> Self {
         Self {
             pending: VecDeque::new(),
-            pending_keys: HashSet::new(),
             bytes: 0,
             capacity,
             byte_budget,
         }
     }
 
-    pub(crate) fn try_push_typed(&mut self, intent: MrfIntent) -> MrfQueuePushResult {
-        if intent.bucket.len() > MRF_MAX_IDENTITY_COMPONENT || intent.object.len() > MRF_MAX_IDENTITY_COMPONENT {
-            counter!("rustfs_heal_mrf_dropped_total", "reason" => "identity_oversized").increment(1);
-            return MrfQueuePushResult::Rejected;
-        }
-        let key = queue_key(&intent);
-        if self.pending_keys.contains(&key) {
-            counter!("rustfs_heal_mrf_coalesced_total", "layer" => "queue").increment(1);
-            return MrfQueuePushResult::Coalesced;
-        }
+    /// Returns `false` (after counting) when either ceiling would be crossed.
+    pub(crate) fn try_push(&mut self, intent: MrfIntent) -> bool {
         let cost = intent.estimated_bytes();
         if self.pending.len() >= self.capacity || self.bytes + cost > self.byte_budget {
             counter!("rustfs_heal_mrf_dropped_total", "reason" => "queue_overflow").increment(1);
-            return MrfQueuePushResult::Rejected;
+            return false;
         }
         self.bytes += cost;
-        self.pending_keys.insert(key);
         self.pending.push_back(intent);
-        MrfQueuePushResult::Enqueued
-    }
-
-    /// Bool compatibility adapter: only a newly executable queue item is
-    /// reported as accepted; a coalesced duplicate is not durable admission.
-    #[cfg(test)]
-    pub(crate) fn try_push(&mut self, intent: MrfIntent) -> bool {
-        matches!(self.try_push_typed(intent), MrfQueuePushResult::Enqueued)
+        true
     }
 
     pub(crate) fn pop_front(&mut self) -> Option<MrfIntent> {
         let intent = self.pending.pop_front()?;
-        self.pending_keys.remove(&queue_key(&intent));
         self.bytes = self.bytes.saturating_sub(intent.estimated_bytes());
         Some(intent)
     }
 
     pub(crate) fn push_back(&mut self, intent: MrfIntent) {
-        self.pending_keys.insert(queue_key(&intent));
         self.bytes += intent.estimated_bytes();
         self.pending.push_back(intent);
     }
@@ -219,24 +157,10 @@ impl MrfQueue {
 // ---------------------------------------------------------------------------
 
 /// Append one encoded record to `out`.
-pub(crate) fn encode_intent(intent: &MrfIntent, out: &mut Vec<u8>) -> bool {
-    let Ok(bucket_len) = u32::try_from(intent.bucket.len()) else {
-        return false;
-    };
-    let Ok(object_len) = u32::try_from(intent.object.len()) else {
-        return false;
-    };
-    let scope = (!matches!(intent.kind, rustfs_common::mrf_channel::MrfKind::MetadataCorruption))
-        .then_some(intent.scope)
-        .flatten();
-    let version_id = intent.version_id.filter(|bytes| *bytes != [0; 16]);
+pub(crate) fn encode_intent(intent: &MrfIntent, out: &mut Vec<u8>) {
     let start = out.len();
     out.push(MRF_JOURNAL_FORMAT);
-    out.push(if scope.is_some() {
-        MRF_JOURNAL_VERSION_SCOPED
-    } else {
-        MRF_JOURNAL_VERSION
-    });
+    out.push(MRF_JOURNAL_VERSION);
     out.push(match intent.kind {
         rustfs_common::mrf_channel::MrfKind::DecodeFailure => 1,
         rustfs_common::mrf_channel::MrfKind::MetadataCorruption => 2,
@@ -244,36 +168,27 @@ pub(crate) fn encode_intent(intent: &MrfIntent, out: &mut Vec<u8>) -> bool {
     });
     out.push(intent.attempts);
     out.extend_from_slice(&intent.enqueued_at_ms.to_le_bytes());
-    match version_id {
+    match intent.version_id {
         Some(bytes) => {
             out.push(1);
             out.extend_from_slice(&bytes);
         }
         None => out.push(0),
     }
-    if let Some(scope) = scope {
-        out.extend_from_slice(&scope.pool_index.to_le_bytes());
-        out.extend_from_slice(&scope.set_index.to_le_bytes());
-    }
-    out.extend_from_slice(&bucket_len.to_le_bytes());
-    out.extend_from_slice(&object_len.to_le_bytes());
+    out.extend_from_slice(&(intent.bucket.len() as u32).to_le_bytes());
+    out.extend_from_slice(&(intent.object.len() as u32).to_le_bytes());
     out.extend_from_slice(intent.bucket.as_bytes());
     out.extend_from_slice(intent.object.as_bytes());
     let mut hasher = crc_fast::Digest::new(crc_fast::CrcAlgorithm::Crc32IsoHdlc);
     hasher.update(&out[start..]);
-    let Ok(checksum) = u32::try_from(hasher.finalize()) else {
-        out.truncate(start);
-        return false;
-    };
-    out.extend_from_slice(&checksum.to_le_bytes());
-    true
+    out.extend_from_slice(&(hasher.finalize() as u32).to_le_bytes());
 }
 
 fn decode_one(data: &[u8]) -> Option<(MrfIntent, usize)> {
     if data.len() < MRF_RECORD_FIXED_HEAD + 8 {
         return None;
     }
-    if data[0] != MRF_JOURNAL_FORMAT || !matches!(data[1], MRF_JOURNAL_VERSION | MRF_JOURNAL_VERSION_SCOPED) {
+    if data[0] != MRF_JOURNAL_FORMAT || data[1] != MRF_JOURNAL_VERSION {
         return None;
     }
     let kind = match data[2] {
@@ -283,38 +198,24 @@ fn decode_one(data: &[u8]) -> Option<(MrfIntent, usize)> {
         _ => return None,
     };
     let attempts = data[3];
-    let enqueued_at_ms = u64::from_le_bytes(data[4..12].try_into().ok()?);
+    let enqueued_at_ms = u64::from_le_bytes(data[4..12].try_into().expect("slice length checked"));
     let has_version = data[12] != 0;
     let mut cursor = MRF_RECORD_FIXED_HEAD;
     let version_id = if has_version {
         if data.len() < cursor + 16 {
             return None;
         }
-        let bytes: [u8; 16] = data[cursor..cursor + 16].try_into().ok()?;
+        let bytes: [u8; 16] = data[cursor..cursor + 16].try_into().expect("slice length checked");
         cursor += 16;
         Some(bytes)
     } else {
         None
     };
-    let scope = if data[1] == MRF_JOURNAL_VERSION_SCOPED {
-        if data.len() < cursor + 8 {
-            return None;
-        }
-        let pool_index = u32::from_le_bytes(data[cursor..cursor + 4].try_into().ok()?);
-        let set_index = u32::from_le_bytes(data[cursor + 4..cursor + 8].try_into().ok()?);
-        cursor += 8;
-        Some(rustfs_common::mrf_channel::MrfScope { pool_index, set_index })
-    } else {
-        None
-    };
     if data.len() < cursor + 8 {
         return None;
     }
-    let bucket_len = usize::try_from(u32::from_le_bytes(data[cursor..cursor + 4].try_into().ok()?)).ok()?;
-    let object_len = usize::try_from(u32::from_le_bytes(data[cursor + 4..cursor + 8].try_into().ok()?)).ok()?;
-    if bucket_len > MRF_MAX_IDENTITY_COMPONENT || object_len > MRF_MAX_IDENTITY_COMPONENT {
-        return None;
-    }
+    let bucket_len = u32::from_le_bytes(data[cursor..cursor + 4].try_into().expect("slice length checked")) as usize;
+    let object_len = u32::from_le_bytes(data[cursor + 4..cursor + 8].try_into().expect("slice length checked")) as usize;
     cursor += 8;
     let body_end = cursor.checked_add(bucket_len)?.checked_add(object_len)?;
     let record_end = body_end.checked_add(4)?;
@@ -323,7 +224,7 @@ fn decode_one(data: &[u8]) -> Option<(MrfIntent, usize)> {
     }
     let mut hasher = crc_fast::Digest::new(crc_fast::CrcAlgorithm::Crc32IsoHdlc);
     hasher.update(&data[..body_end]);
-    if u32::try_from(hasher.finalize()).ok()? != u32::from_le_bytes(data[body_end..record_end].try_into().ok()?) {
+    if (hasher.finalize() as u32) != u32::from_le_bytes(data[body_end..record_end].try_into().expect("slice length checked")) {
         return None;
     }
     let bucket = std::sync::Arc::from(std::str::from_utf8(&data[cursor..cursor + bucket_len]).ok()?);
@@ -334,12 +235,6 @@ fn decode_one(data: &[u8]) -> Option<(MrfIntent, usize)> {
             object,
             version_id,
             kind,
-            scope: if matches!(kind, rustfs_common::mrf_channel::MrfKind::MetadataCorruption) {
-                None
-            } else {
-                scope
-            },
-            lease: None,
             enqueued_at_ms,
             attempts,
         },
@@ -374,9 +269,9 @@ async fn journal_disks() -> Vec<DiskStore> {
     map.values().flatten().cloned().collect()
 }
 
-async fn read_journal(path: &str) -> Option<Vec<u8>> {
+async fn read_journal() -> Option<Vec<u8>> {
     for disk in journal_disks().await {
-        match disk.read_all(super::RUSTFS_META_BUCKET, path).await {
+        match disk.read_all(super::RUSTFS_META_BUCKET, MRF_JOURNAL_PATH).await {
             Ok(bytes) => return Some(bytes.to_vec()),
             Err(_) => continue,
         }
@@ -387,51 +282,35 @@ async fn read_journal(path: &str) -> Option<Vec<u8>> {
 /// Write the snapshot to every local disk; returns true when at least one
 /// disk accepted it, so a total write failure keeps the runtime dirty and
 /// the next tick retries the persist.
-async fn write_journal(path: &str, data: &[u8]) -> bool {
+async fn write_journal(data: &[u8]) -> bool {
     let payload = bytes::Bytes::copy_from_slice(data);
     let mut any_persisted = false;
     for disk in journal_disks().await {
-        match disk.write_all(super::RUSTFS_META_BUCKET, path, payload.clone()).await {
+        match disk
+            .write_all(super::RUSTFS_META_BUCKET, MRF_JOURNAL_PATH, payload.clone())
+            .await
+        {
             Ok(()) => any_persisted = true,
             Err(err) => warn_mrf_journal_write(&err),
         }
     }
+    if !data.is_empty() {
+        counter!("rustfs_heal_mrf_journal_fsync_total").increment(1);
+    }
+    gauge!("rustfs_heal_mrf_journal_bytes").set(data.len() as f64);
     any_persisted
 }
 
-async fn delete_journal(path: &str) -> bool {
-    let disks = journal_disks().await;
-    if disks.is_empty() {
-        counter!("rustfs_heal_mrf_journal_delete_failures_total").increment(1);
-        return false;
-    }
-    let mut all_deleted = true;
-    for disk in disks {
-        let result = disk
+async fn delete_journal() {
+    for disk in journal_disks().await {
+        let _ = disk
             .delete(
                 super::RUSTFS_META_BUCKET,
-                path,
+                MRF_JOURNAL_PATH,
                 crate::heal::storage_api::owner::EcstoreDeleteOptions::default(),
             )
             .await;
-        if let Err(err) = result {
-            // Delete is idempotent: a compatibility mirror that was never
-            // written (or was already removed) is clean, not a retry state.
-            if !matches!(err, super::DiskError::FileNotFound | super::DiskError::VolumeNotFound) {
-                all_deleted = false;
-            }
-        }
     }
-    if !all_deleted {
-        counter!("rustfs_heal_mrf_journal_delete_failures_total").increment(1);
-    }
-    all_deleted
-}
-
-async fn delete_journals() -> bool {
-    let authoritative_deleted = delete_journal(MRF_SCOPED_JOURNAL_PATH).await;
-    let legacy_deleted = delete_journal(MRF_JOURNAL_PATH).await;
-    authoritative_deleted && legacy_deleted
 }
 
 fn warn_mrf_journal_write(err: &super::DiskError) {
@@ -452,10 +331,7 @@ fn warn_mrf_journal_write(err: &super::DiskError) {
 pub(crate) fn build_heal_request(intent: &MrfIntent) -> HealRequest {
     let bucket = intent.bucket.to_string();
     let object = intent.object.to_string();
-    let version_id = intent
-        .version_id
-        .filter(|bytes| *bytes != [0; 16])
-        .map(|bytes| Uuid::from_bytes(bytes).to_string());
+    let version_id = intent.version_id.map(|bytes| Uuid::from_bytes(bytes).to_string());
     let (heal_type, priority) = match intent.kind {
         rustfs_common::mrf_channel::MrfKind::DecodeFailure => (
             HealType::ECDecode {
@@ -475,28 +351,18 @@ pub(crate) fn build_heal_request(intent: &MrfIntent) -> HealRequest {
             HealPriority::Normal,
         ),
     };
-    let mut options = HealOptions::default();
-    if !matches!(intent.kind, rustfs_common::mrf_channel::MrfKind::MetadataCorruption)
-        && let Some(scope) = intent.scope
-    {
-        options.pool_index = usize::try_from(scope.pool_index).ok();
-        options.set_index = usize::try_from(scope.set_index).ok();
-    }
-    let mut request = HealRequest::new(heal_type, options, priority);
+    let mut request = HealRequest::new(heal_type, HealOptions::default(), priority);
     request.source = rustfs_common::heal_channel::HealRequestSource::Mrf;
     request
 }
 
 async fn submit_mrf_heal_request(manager: &HealManager, intent: &MrfIntent) -> crate::Result<HealAdmissionResult> {
     let receipt = manager
-        .submit_mrf_heal_request_with_receipt_and_identity(
+        .submit_mrf_heal_request_with_receipt(
             build_heal_request(intent),
             intent.bucket.clone(),
             intent.object.clone(),
             intent.version_id,
-            intent.kind,
-            intent.scope,
-            intent.lease,
         )
         .await?;
     Ok(receipt.result)
@@ -521,38 +387,16 @@ struct MrfRuntime {
 }
 
 impl MrfRuntime {
-    fn snapshot(&self) -> (Vec<u8>, Vec<u8>) {
-        let mut authoritative = Vec::new();
-        let mut legacy = Vec::new();
+    fn snapshot(&self) -> Vec<u8> {
+        let mut buf = Vec::new();
         for intent in self.queue.intents() {
-            let scoped_identity =
-                !matches!(intent.kind, rustfs_common::mrf_channel::MrfKind::MetadataCorruption) && intent.scope.is_some();
-            if !encode_intent(intent, &mut authoritative) {
-                counter!("rustfs_heal_mrf_dropped_total", "reason" => "journal_identity_oversized").increment(1);
-            }
-            if !scoped_identity && !encode_intent(intent, &mut legacy) {
-                counter!("rustfs_heal_mrf_dropped_total", "reason" => "journal_identity_oversized").increment(1);
-            }
+            encode_intent(intent, &mut buf);
         }
-        (authoritative, legacy)
+        buf
     }
 
     async fn flush(&mut self) {
-        let (authoritative, legacy) = self.snapshot();
-        let authoritative_persisted = write_journal(MRF_SCOPED_JOURNAL_PATH, &authoritative).await;
-        if !authoritative.is_empty() {
-            counter!("rustfs_heal_mrf_journal_fsync_total").increment(1);
-        }
-        gauge!("rustfs_heal_mrf_journal_bytes").set(metric_f64(authoritative.len()));
-        // Publish the compatibility mirror only after the authoritative
-        // snapshot has reached at least one disk. This ordering prevents an
-        // old reader from observing a newer epoch that a new reader cannot
-        // see when the canonical write is unavailable.
-        let legacy_persisted = authoritative_persisted && write_journal(MRF_JOURNAL_PATH, &legacy).await;
-        // Keep dirty until both the authoritative snapshot and its
-        // compatibility mirror have been accepted; otherwise a one-sided
-        // failure would never retry the missing file.
-        let persisted = authoritative_persisted && legacy_persisted;
+        let persisted = write_journal(&self.snapshot()).await;
         self.new_since_flush = 0;
         // Keep the dirty flag when every disk write failed: a clean backlog
         // would otherwise never rewrite, losing the periodic persist retry a
@@ -560,7 +404,7 @@ impl MrfRuntime {
         if persisted {
             self.dirty = false;
         }
-        self.journal_on_disk |= authoritative_persisted || legacy_persisted;
+        self.journal_on_disk = true;
     }
 
     /// Drain pending intents into the heal manager until it is full, the
@@ -586,7 +430,6 @@ impl MrfRuntime {
                     intent.attempts = intent.attempts.saturating_add(1);
                     if intent.attempts >= MRF_MAX_ATTEMPTS {
                         counter!("rustfs_heal_mrf_dropped_total", "reason" => "attempts_exhausted").increment(1);
-                        rustfs_common::mrf_channel::release_mrf_intent(&intent);
                         continue;
                     }
                     self.queue.push_back(intent);
@@ -595,13 +438,11 @@ impl MrfRuntime {
                 }
                 Ok(HealAdmissionResult::Dropped(_)) => {
                     counter!("rustfs_heal_mrf_dropped_total", "reason" => "admission_policy").increment(1);
-                    rustfs_common::mrf_channel::release_mrf_intent(&intent);
                 }
                 Err(_) => {
                     intent.attempts = intent.attempts.saturating_add(1);
                     if intent.attempts >= MRF_MAX_ATTEMPTS {
                         counter!("rustfs_heal_mrf_dropped_total", "reason" => "attempts_exhausted").increment(1);
-                        rustfs_common::mrf_channel::release_mrf_intent(&intent);
                         continue;
                     }
                     self.queue.push_back(intent);
@@ -610,8 +451,8 @@ impl MrfRuntime {
                 }
             }
         }
-        gauge!("rustfs_heal_mrf_queue_depth").set(metric_f64(self.queue.depth()));
-        gauge!("rustfs_heal_mrf_queue_bytes").set(metric_f64(self.queue.bytes()));
+        gauge!("rustfs_heal_mrf_queue_depth").set(self.queue.depth() as f64);
+        gauge!("rustfs_heal_mrf_queue_bytes").set(self.queue.bytes() as f64);
     }
 }
 
@@ -655,12 +496,7 @@ pub async fn replay_journal_once(manager: &Arc<HealManager>) -> usize {
     let config = MrfConsumerConfig::default();
     let mut queue = MrfQueue::new(config.queue_capacity, config.journal_max_bytes);
     let mut backoff_until: Option<tokio::time::Instant> = None;
-    replay_into(manager, &mut queue, &mut backoff_until).await.replayed
-}
-
-struct ReplayOutcome {
-    replayed: usize,
-    journal_on_disk: bool,
+    replay_into(manager, &mut queue, &mut backoff_until).await
 }
 
 /// Shared replay core: read + decode + re-arm + delete, then drain what fits.
@@ -668,25 +504,11 @@ async fn replay_into(
     manager: &Arc<HealManager>,
     queue: &mut MrfQueue,
     backoff_until: &mut Option<tokio::time::Instant>,
-) -> ReplayOutcome {
-    // The scoped file is a complete authoritative snapshot. Fall back to the
-    // legacy mirror only when the authoritative path is unavailable; merging
-    // both files could combine records from different flush epochs.
-    let data = match read_journal(MRF_SCOPED_JOURNAL_PATH).await {
-        Some(data) => data,
-        None => match read_journal(MRF_JOURNAL_PATH).await {
-            Some(data) => data,
-            None => {
-                return ReplayOutcome {
-                    replayed: 0,
-                    journal_on_disk: false,
-                };
-            }
-        },
+) -> usize {
+    let Some(data) = read_journal().await else {
+        return 0;
     };
-    let mut intents = Vec::new();
-    let (decoded, truncated) = decode_journal(&data);
-    intents.extend(decoded);
+    let (intents, truncated) = decode_journal(&data);
     if truncated > 0 {
         tracing::warn!(
             target: "rustfs::heal::mrf",
@@ -694,15 +516,12 @@ async fn replay_into(
             "MRF journal had a torn tail; truncated records were discarded"
         );
     }
-    counter!("rustfs_heal_mrf_replayed_total").increment(u64::try_from(intents.len()).unwrap_or(u64::MAX));
+    counter!("rustfs_heal_mrf_replayed_total").increment(intents.len() as u64);
     let replayed = intents.len();
     for intent in intents {
-        let result = queue.try_push_typed(intent.clone());
-        if !matches!(result, MrfQueuePushResult::Enqueued) {
-            rustfs_common::mrf_channel::release_mrf_intent(&intent);
-        }
+        queue.try_push(intent);
     }
-    let journal_on_disk = !delete_journals().await;
+    delete_journal().await;
 
     // Drain the replayed intents immediately; whatever the manager refuses
     // stays armed in `queue` for the consumer's retry loop.
@@ -722,10 +541,7 @@ async fn replay_into(
             }
         }
     }
-    ReplayOutcome {
-        replayed,
-        journal_on_disk,
-    }
+    replayed
 }
 
 /// Replay the journal, then keep draining the channel into the heal manager
@@ -743,8 +559,7 @@ async fn run_mrf_consumer(manager: Arc<HealManager>, mut receiver: mpsc::Receive
 
     // Replay: read the journal, re-arm intents (duplicates are merged by the
     // manager's dedup key), then drop the file so the next flush starts clean.
-    let replay = replay_into(&manager, &mut runtime.queue, &mut runtime.backoff_until).await;
-    runtime.journal_on_disk = replay.journal_on_disk;
+    replay_into(&manager, &mut runtime.queue, &mut runtime.backoff_until).await;
     // The replay deleted the journal file; anything still pending (e.g. the
     // manager was full and backoff armed) must be re-persisted by the next
     // flush or a crash before it would lose those intents.
@@ -772,14 +587,9 @@ async fn run_mrf_consumer(manager: Arc<HealManager>, mut receiver: mpsc::Receive
                     return;
                 }
                 for intent in batch.drain(..) {
-                    match runtime.queue.try_push_typed(intent.clone()) {
-                        MrfQueuePushResult::Enqueued => {
-                            runtime.new_since_flush += 1;
-                            runtime.dirty = true;
-                        }
-                        MrfQueuePushResult::Coalesced | MrfQueuePushResult::Rejected => {
-                            rustfs_common::mrf_channel::release_mrf_intent(&intent);
-                        }
+                    if runtime.queue.try_push(intent) {
+                        runtime.new_since_flush += 1;
+                        runtime.dirty = true;
                     }
                 }
                 runtime.dispatch(manager.as_ref()).await;
@@ -803,14 +613,13 @@ async fn run_mrf_consumer(manager: Arc<HealManager>, mut receiver: mpsc::Receive
                     TickAction::DeleteJournal => {
                         // All intents consumed: remove the journal so a restart
                         // replays nothing (mirrors MinIO's post-replay unlink).
-                        if delete_journals().await {
-                            runtime.journal_on_disk = false;
-                            gauge!("rustfs_heal_mrf_journal_bytes").set(0.0);
-                        }
+                        delete_journal().await;
+                        runtime.journal_on_disk = false;
+                        gauge!("rustfs_heal_mrf_journal_bytes").set(0.0);
                     }
                     TickAction::Idle => {}
                 }
-                gauge!("rustfs_heal_mrf_queue_depth").set(metric_f64(runtime.queue.depth()));
+                gauge!("rustfs_heal_mrf_queue_depth").set(runtime.queue.depth() as f64);
             }
         }
     }
@@ -855,8 +664,6 @@ mod tests {
             object: StdArc::from(object),
             version_id: Some([7u8; 16]),
             kind: MrfKind::DecodeFailure,
-            scope: None,
-            lease: None,
             enqueued_at_ms: 1_700_000_000_000,
             attempts,
         }
@@ -887,101 +694,17 @@ mod tests {
     fn queue_enforces_count_and_byte_ceilings() {
         let mut queue = MrfQueue::new(2, usize::MAX);
         assert!(queue.try_push(intent("b", "o", 0)));
-        assert!(queue.try_push(intent("b", "o2", 0)));
-        assert!(!queue.try_push(intent("b", "o3", 0)), "count ceiling must drop");
+        assert!(queue.try_push(intent("b", "o", 0)));
+        assert!(!queue.try_push(intent("b", "o", 0)), "count ceiling must drop");
 
         let mut tiny = MrfQueue::new(usize::MAX, intent("bucket", "object", 0).estimated_bytes());
         assert!(tiny.try_push(intent("bucket", "object", 0)));
         assert!(
-            !tiny.try_push(intent("bucket", "object2", 0)),
+            !tiny.try_push(intent("bucket", "object", 0)),
             "byte budget must drop before the second intent fits"
         );
     }
 
-    #[test]
-    fn duplicate_mrf_intents_coalesce_to_one_execution() {
-        let mut queue = MrfQueue::new(1000, usize::MAX);
-        let mut enqueued = 0;
-        let mut coalesced = 0;
-        assert_eq!(queue.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-        enqueued += 1;
-        for _ in 0..999 {
-            match queue.try_push_typed(intent("bucket", "object", 0)) {
-                MrfQueuePushResult::Coalesced => coalesced += 1,
-                other => panic!("duplicate intent was not coalesced: {other:?}"),
-            }
-        }
-        assert_eq!(enqueued, 1);
-        assert_eq!(coalesced, 999);
-        assert_eq!(queue.depth(), 1);
-    }
-
-    #[test]
-    fn mrf_dedupe_does_not_merge_adjacent_version_pool_or_kind() {
-        let mut queue = MrfQueue::new(8, usize::MAX);
-        let mut first = intent("bucket", "object", 0);
-        first.kind = MrfKind::PartialWrite;
-        first.scope = Some(rustfs_common::mrf_channel::MrfScope {
-            pool_index: 1,
-            set_index: 1,
-        });
-        assert!(queue.try_push(first.clone()));
-        first.version_id = Some([8u8; 16]);
-        assert!(queue.try_push(first));
-        let mut other_scope = intent("bucket", "object", 0);
-        other_scope.kind = MrfKind::PartialWrite;
-        other_scope.scope = Some(rustfs_common::mrf_channel::MrfScope {
-            pool_index: 2,
-            set_index: 1,
-        });
-        assert!(queue.try_push(other_scope));
-        let mut other_kind = intent("bucket", "object", 0);
-        other_kind.kind = MrfKind::DecodeFailure;
-        other_kind.scope = None;
-        assert!(queue.try_push(other_kind));
-        assert_eq!(queue.depth(), 4);
-    }
-
-    #[test]
-    fn mrf_dedupe_full_returns_rejected_with_durable_pending() {
-        let mut queue = MrfQueue::new(1, usize::MAX);
-        assert_eq!(queue.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-        assert_eq!(queue.try_push_typed(intent("bucket", "other", 0)), MrfQueuePushResult::Rejected);
-        assert_eq!(queue.depth(), 1);
-        let mut snapshot = Vec::new();
-        assert!(encode_intent(queue.intents().next().expect("resident intent"), &mut snapshot));
-        assert!(!snapshot.is_empty(), "the resident intent remains journalable after rejection");
-    }
-
-    #[test]
-    fn mrf_dedupe_failure_releases_key_for_retry() {
-        let mut queue = MrfQueue::new(1, usize::MAX);
-        assert_eq!(queue.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-        let _failed = queue.pop_front().expect("queued intent");
-        assert_eq!(queue.try_push_typed(intent("bucket", "object", 1)), MrfQueuePushResult::Enqueued);
-        assert_eq!(queue.depth(), 1);
-    }
-
-    #[test]
-    fn mrf_dedupe_key_and_map_are_bounded() {
-        let mut queue = MrfQueue::new(2, usize::MAX);
-        assert_eq!(queue.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-        assert_eq!(queue.try_push_typed(intent("bucket", "other", 0)), MrfQueuePushResult::Enqueued);
-        assert_eq!(queue.pending_keys.len(), 2);
-        assert_eq!(queue.try_push_typed(intent("bucket", "third", 0)), MrfQueuePushResult::Rejected);
-        assert_eq!(queue.depth(), 2);
-    }
-
-    #[test]
-    fn cross_node_duplicate_execution_remains_idempotent() {
-        // Node-local ingress maps intentionally do not merge across nodes;
-        // the manager's existing identity key absorbs the duplicate later.
-        let mut node_a = MrfQueue::new(8, usize::MAX);
-        let mut node_b = MrfQueue::new(8, usize::MAX);
-        assert_eq!(node_a.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-        assert_eq!(node_b.try_push_typed(intent("bucket", "object", 0)), MrfQueuePushResult::Enqueued);
-    }
-
     #[test]
     fn journal_roundtrip_preserves_intents() {
         let intents = vec![
@@ -992,8 +715,6 @@ mod tests {
                 object: StdArc::from("object/c"),
                 version_id: None,
                 kind: MrfKind::MetadataCorruption,
-                scope: None,
-                lease: None,
                 enqueued_at_ms: 5,
                 attempts: 1,
             },
@@ -1045,8 +766,6 @@ mod tests {
             object: StdArc::from("o"),
             version_id: None,
             kind: MrfKind::MetadataCorruption,
-            scope: None,
-            lease: None,
             enqueued_at_ms: 0,
             attempts: 0,
         });
@@ -1058,8 +777,6 @@ mod tests {
             object: StdArc::from("o"),
             version_id: None,
             kind: MrfKind::PartialWrite,
-            scope: None,
-            lease: None,
             enqueued_at_ms: 0,
             attempts: 0,
         });

crates/heal/tests/mrf_pipeline_test.rs

@@ -35,7 +35,6 @@ use storage_api::endpoint_index::{Endpoint, EndpointServerPools, Endpoints, Pool
 
 const META_BUCKET: &str = ".rustfs.sys";
 const JOURNAL_REL: &str = "buckets/.heal/mrf/journal.bin";
-const SCOPED_JOURNAL_REL: &str = "buckets/.heal/mrf/journal-scoped.bin";
 
 async fn heal_env() -> (Vec<std::path::PathBuf>, Arc<dyn HealStorageAPI>) {
     let env = rustfs_test_utils::TestECStoreEnv::builder()
@@ -80,18 +79,14 @@ fn journal_record(kind: u8, bucket: &str, object: &str, version: Option<[u8; 16]
     body
 }
 
-fn write_journal_path_to_disks(disk_paths: &[std::path::PathBuf], relative_path: &str, data: &[u8]) {
+fn write_journal_to_disks(disk_paths: &[std::path::PathBuf], data: &[u8]) {
     for path in disk_paths {
-        let journal = path.join(META_BUCKET).join(relative_path);
+        let journal = path.join(META_BUCKET).join(JOURNAL_REL);
         std::fs::create_dir_all(journal.parent().expect("journal parent")).expect("create journal dir");
         std::fs::write(&journal, data).expect("write journal fixture");
     }
 }
 
-fn write_journal_to_disks(disk_paths: &[std::path::PathBuf], data: &[u8]) {
-    write_journal_path_to_disks(disk_paths, JOURNAL_REL, data);
-}
-
 async fn wait_until<F, Fut>(deadline: Duration, mut probe: F) -> bool
 where
     F: FnMut() -> Fut,
@@ -192,73 +187,8 @@ async fn journal_replay_arms_intents_and_deletes_the_file() {
             .all(|path| !Path::new(path).join(META_BUCKET).join(JOURNAL_REL).exists()),
         "the journal file must be removed after a successful replay"
     );
-    assert!(
-        disk_paths
-            .iter()
-            .all(|path| !Path::new(path).join(META_BUCKET).join(SCOPED_JOURNAL_REL).exists()),
-        "the authoritative journal file must also be removed after replay"
-    );
 
     let snapshot = manager.operations_snapshot().await;
     assert_eq!(snapshot.queued_by_priority.urgent, 1, "the decode-failure record must replay as Urgent");
     assert!(snapshot.queued_by_priority.normal >= 1, "the partial-write record must replay as Normal");
 }
-
-/// A canonical snapshot and its compatibility mirror may differ after a
-/// partial flush. Replay must choose the complete canonical epoch instead of
-/// combining records that never coexisted in memory.
-#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
-#[serial]
-async fn authoritative_journal_is_not_merged_with_legacy_mirror() {
-    let (disk_paths, storage) = heal_env().await;
-    let mut endpoints: Vec<Endpoint> = disk_paths
-        .iter()
-        .map(|p| Endpoint::try_from(p.to_string_lossy().as_ref()).expect("endpoint from disk path"))
-        .collect();
-    for (i, endpoint) in endpoints.iter_mut().enumerate() {
-        endpoint.set_pool_index(0);
-        endpoint.set_set_index(0);
-        endpoint.set_disk_index(i);
-    }
-    let pool = PoolEndpoints {
-        legacy: false,
-        set_count: 1,
-        drives_per_set: endpoints.len(),
-        endpoints: Endpoints::from(endpoints),
-        cmd_line: "mrf-authoritative-test".to_string(),
-        platform: String::new(),
-    };
-    init_local_disks(EndpointServerPools::from(vec![pool]))
-        .await
-        .expect("local disks should register");
-
-    let authoritative = journal_record(1, "authoritative-bucket", "authoritative-object", None, 0);
-    let legacy = journal_record(1, "legacy-bucket", "legacy-object", None, 0);
-    write_journal_path_to_disks(&disk_paths, SCOPED_JOURNAL_REL, &authoritative);
-    write_journal_path_to_disks(&disk_paths, JOURNAL_REL, &legacy);
-
-    let manager = make_manager(storage);
-    let replayed = mrf_queue::replay_journal_once(&manager).await;
-    assert_eq!(replayed, 1, "only the authoritative snapshot epoch may replay");
-
-    let snapshot = manager.operations_snapshot().await;
-    assert_eq!(snapshot.queued_by_source.mrf, 1);
-    assert!(
-        disk_paths.iter().all(|path| {
-            !Path::new(path).join(META_BUCKET).join(JOURNAL_REL).exists()
-                && !Path::new(path).join(META_BUCKET).join(SCOPED_JOURNAL_REL).exists()
-        }),
-        "replay cleanup must remove both journal paths"
-    );
-
-    // A scoped-only snapshot is valid during a rollout where no legacy
-    // compatibility mirror was written. Missing legacy files must not leave
-    // the runtime in a permanent cleanup-retry state.
-    let scoped_only = journal_record(1, "scoped-only-bucket", "scoped-only-object", None, 0);
-    write_journal_path_to_disks(&disk_paths, SCOPED_JOURNAL_REL, &scoped_only);
-    assert_eq!(mrf_queue::replay_journal_once(&manager).await, 1);
-    assert!(disk_paths.iter().all(|path| {
-        !Path::new(path).join(META_BUCKET).join(JOURNAL_REL).exists()
-            && !Path::new(path).join(META_BUCKET).join(SCOPED_JOURNAL_REL).exists()
-    }));
-}

crates/scanner/src/scanner_folder.rs

@@ -1375,14 +1375,13 @@ impl FolderScanner {
                             // Single-flight (backlog#1894 axis A) — the
                             // recording mode and its guarantees are pinned by
                             // corrupt_metadata_recording below.
-                            let mrf_result = rustfs_common::mrf_channel::try_send_mrf_intent_typed(
+                            let mrf_accepted = rustfs_common::mrf_channel::try_send_mrf_intent(
                                 rustfs_common::mrf_channel::MrfKind::MetadataCorruption,
                                 &item.bucket,
                                 &object,
                                 None,
-                                None,
                             );
-                            match corrupt_metadata_recording(mrf_result) {
+                            match corrupt_metadata_recording(mrf_accepted) {
                                 CorruptMetadataRecording::LedgerOnly => {
                                     // Recorded as Full (retry-later): admission
                                     // for this target happens in the MRF

crates/scanner/src/scanner_folder/item_actions.rs

@@ -50,12 +50,11 @@ pub(super) enum CorruptMetadataRecording {
     ImmediateAndLedger,
 }
 
-pub(super) fn corrupt_metadata_recording(result: rustfs_common::mrf_channel::MrfIngressResult) -> CorruptMetadataRecording {
-    match result {
-        rustfs_common::mrf_channel::MrfIngressResult::Enqueued | rustfs_common::mrf_channel::MrfIngressResult::Coalesced => {
-            CorruptMetadataRecording::LedgerOnly
-        }
-        rustfs_common::mrf_channel::MrfIngressResult::Dropped(_) => CorruptMetadataRecording::ImmediateAndLedger,
+pub(super) fn corrupt_metadata_recording(mrf_accepted: bool) -> CorruptMetadataRecording {
+    if mrf_accepted {
+        CorruptMetadataRecording::LedgerOnly
+    } else {
+        CorruptMetadataRecording::ImmediateAndLedger
     }
 }
 

crates/scanner/src/scanner_folder/tests.rs

@@ -48,20 +48,8 @@ fn scanner_alert_wire_names_match_canonical_event_names() {
 /// the backstop survives regardless of delivery.
 #[test]
 fn corrupt_metadata_recording_maps_delivery_to_backstop() {
-    assert_eq!(
-        corrupt_metadata_recording(rustfs_common::mrf_channel::MrfIngressResult::Enqueued),
-        CorruptMetadataRecording::LedgerOnly
-    );
-    assert_eq!(
-        corrupt_metadata_recording(rustfs_common::mrf_channel::MrfIngressResult::Coalesced),
-        CorruptMetadataRecording::LedgerOnly
-    );
-    assert_eq!(
-        corrupt_metadata_recording(rustfs_common::mrf_channel::MrfIngressResult::Dropped(
-            rustfs_common::mrf_channel::MrfDropReason::Full
-        )),
-        CorruptMetadataRecording::ImmediateAndLedger
-    );
+    assert_eq!(corrupt_metadata_recording(true), CorruptMetadataRecording::LedgerOnly);
+    assert_eq!(corrupt_metadata_recording(false), CorruptMetadataRecording::ImmediateAndLedger);
 }
 
 fn cooldown_map_len() -> usize {