v0.24.7

src/cache/collapse.rs

@@ -210,6 +210,19 @@ impl Cache {
             .proactive_scheduled_keys
             .lock()
             .unwrap_or_else(|e| e.into_inner());
+        // Each scheduled key owns a sleeping Tokio task plus refresh context.
+        // Bound the pending set independently from the cache entry count so a
+        // large cache with long TTLs cannot turn into thousands of resident tasks.
+        let pending_limit = settings
+            .proactive_refresh_max_inflight
+            .saturating_mul(64)
+            .clamp(64, 256);
+        if scheduled.len() >= pending_limit && !scheduled.contains(&ticket.key) {
+            self.counters
+                .proactive_skipped
+                .fetch_add(1, Ordering::Relaxed);
+            return None;
+        }
         if !scheduled.insert(ticket.key) {
             return None;
         }