# UNDF: UNDF-2026-000000302
--- a/storm-client/src/jvm/org/apache/storm/daemon/worker/WorkerState.java
+++ b/storm-client/src/jvm/org/apache/storm/daemon/worker/WorkerState.java
@@ -110,2 +110,3 @@
     // local executors and localTaskIds running in this worker
     final Set<List<Long>> localExecutors;
     final ArrayList<Integer> localTaskIds;
+    final HashSet<Integer> localTaskIdSet;   // O(1) membership shadow of localTaskIds

@@ -194,2 +194,3 @@
         this.localTaskIds = new ArrayList<>();
+        this.localTaskIdSet = new HashSet<>();
         this.taskToExecutorQueue = new HashMap<>();

@@ -202,1 +202,2 @@
             this.localTaskIds.addAll(taskIds);
+            this.localTaskIdSet.addAll(taskIds);

@@ -428,3 +428,3 @@
-                    if (!localTaskIds.contains(task)) {
+                    if (!localTaskIdSet.contains(task)) {
                         neededConnections.add(taskToNodePortEntry.getValue());
                     }