diff --git a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java
index 4743a26101..a68bafe61c 100644
--- a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java
+++ b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java
@@ -223,6 +223,7 @@ public void onComplete() {
     }
 
     private void response(Map<Integer, ModelTensors> tensors) {
+        // when countdown's count equals to 0 means all responses are received.
         if (countDownLatch.getCountDownLatch().getCount() == 0) {
             reOrderTensorResponses(tensors);
         } else {