Fix memory leak issue in ReorganizingLongHash (#11953)

Signed-off-by: Neetika Singhal <[email protected]>

CHANGELOG.md

@@ -236,6 +236,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix issue when calling Delete PIT endpoint and no PITs exist ([#11711](https://github.com/opensearch-project/OpenSearch/pull/11711))
 - Fix tracing context propagation for local transport instrumentation ([#11490](https://github.com/opensearch-project/OpenSearch/pull/11490))
 - Fix parsing of single line comments in `lang-painless` ([#11815](https://github.com/opensearch-project/OpenSearch/issues/11815))
+- Fix memory leak issue in ReorganizingLongHash ([#11953](https://github.com/opensearch-project/OpenSearch/issues/11953))
 
 ### Security
 

server/src/main/java/org/opensearch/common/util/ReorganizingLongHash.java

@@ -118,10 +118,17 @@ public ReorganizingLongHash(final long initialCapacity, final float loadFactor,
         mask = capacity - 1;
         grow = (long) (capacity * loadFactor);
         size = 0;
-
-        table = bigArrays.newLongArray(capacity, false);
-        table.fill(0, capacity, -1);  // -1 represents an empty slot
-        keys = bigArrays.newLongArray(initialCapacity, false);
+        try {
+            table = bigArrays.newLongArray(capacity, false);
+            table.fill(0, capacity, -1);  // -1 represents an empty slot
+            keys = bigArrays.newLongArray(initialCapacity, false);
+        } finally {
+            if (table == null || keys == null) {
+                // it's important to close the arrays initialized above to prevent memory leak
+                // refer: https://github.com/opensearch-project/OpenSearch/issues/10154
+                Releasables.closeWhileHandlingException(table, keys);
+            }
+        }
     }
 
     /**