diff --git a/src/main/java/com/actiontech/dble/services/BackendService.java b/src/main/java/com/actiontech/dble/services/BackendService.java
index 15fe03f1f..f6bd1b1c9 100644
--- a/src/main/java/com/actiontech/dble/services/BackendService.java
+++ b/src/main/java/com/actiontech/dble/services/BackendService.java
@@ -335,10 +335,8 @@ public abstract class BackendService extends AbstractService {
 
     public void releaseSignal() {
         isRowDataFlowing = false;
-        if (recycler != null) {
-            recycler.signal();
-            recycler = null;
-        }
+        Optional.ofNullable(recycler).ifPresent(res -> res.signal());
+        recycler = null;
     }
 
     public void resetContextStatus() {