diff --git a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeHandler.java b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeHandler.java
index 4229916aa..ad791603a 100644
--- a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeHandler.java
+++ b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeHandler.java
@@ -34,6 +34,7 @@ public abstract class MultiNodeHandler implements ResponseHandler {
     protected Set<RouteResultsetNode> unResponseRrns = Sets.newConcurrentHashSet();
     protected int errorConnsCnt = 0;
     protected boolean firstResponsed = false;
+    protected boolean complexQuery = false;
 
     public MultiNodeHandler(NonBlockingSession session) {
         if (session == null) {
diff --git a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeQueryHandler.java b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeQueryHandler.java
index 861b463a5..ea34729b5 100644
--- a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeQueryHandler.java
+++ b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeQueryHandler.java
@@ -171,6 +171,7 @@ public class MultiNodeQueryHandler extends MultiNodeHandler implements LoadDataR
         }
         conn.getBackendService().setResponseHandler(this);
         conn.getBackendService().setSession(session);
+        conn.getBackendService().setComplexQuery(complexQuery);
         conn.getBackendService().executeMultiNode(node, session.getShardingService(), sessionAutocommit && !session.getShardingService().isTxStart() && !node.isModifySQL());
     }
 
diff --git a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeSelectHandler.java b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeSelectHandler.java
index f09e1d53e..debcc9bf7 100644
--- a/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeSelectHandler.java
+++ b/src/main/java/com/actiontech/dble/backend/mysql/nio/handler/MultiNodeSelectHandler.java
@@ -51,6 +51,7 @@ public class MultiNodeSelectHandler extends MultiNodeQueryHandler {
 
     public MultiNodeSelectHandler(RouteResultset rrs, NonBlockingSession session) {
         super(rrs, session, false);
+        this.complexQuery = true;
         this.queueSize = SystemConfig.getInstance().getMergeQueueSize();
         this.queues = new ConcurrentHashMap<>();
         if (CollectionUtil.isEmpty(rrs.getSelectCols())) {
@@ -213,7 +214,7 @@ public class MultiNodeSelectHandler extends MultiNodeQueryHandler {
             }
             while (!heap.isEmpty()) {
                 if (isFail())
-                    return;
+                    break;
                 HeapItem top = heap.peak();
                 if (top.isNullItem()) {
                     heap.poll();
@@ -256,7 +257,9 @@ public class MultiNodeSelectHandler extends MultiNodeQueryHandler {
             }
             QueryResultDispatcher.doSqlStat(rrs, session, selectRows, netOutBytes, resultSize);
             assert service != null;
-            nextHandler.rowEofResponse(null, false, service);
+            if (!isFail()) {
+                nextHandler.rowEofResponse(null, false, service);
+            }
         } catch (MySQLOutPutException e) {
             String msg = e.getLocalizedMessage();
             LOGGER.info(msg, e);
diff --git a/src/main/java/com/actiontech/dble/services/mysqlauthenticate/MySQLBackAuthService.java b/src/main/java/com/actiontech/dble/services/mysqlauthenticate/MySQLBackAuthService.java
index 7e138e3f6..a2c636f8e 100644
--- a/src/main/java/com/actiontech/dble/services/mysqlauthenticate/MySQLBackAuthService.java
+++ b/src/main/java/com/actiontech/dble/services/mysqlauthenticate/MySQLBackAuthService.java
@@ -6,6 +6,7 @@
 package com.actiontech.dble.services.mysqlauthenticate;
 
 import com.actiontech.dble.DbleServer;
+import com.actiontech.dble.backend.heartbeat.HeartbeatSQLJob;
 import com.actiontech.dble.backend.mysql.CharsetUtil;
 import com.actiontech.dble.backend.mysql.nio.handler.ResponseHandler;
 import com.actiontech.dble.backend.pool.PooledConnectionListener;
@@ -27,6 +28,7 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
+import java.util.concurrent.Executor;
 
 import static com.actiontech.dble.config.ErrorCode.ER_ACCESS_DENIED_ERROR;
 
@@ -46,9 +48,13 @@ public class MySQLBackAuthService extends BackendService implements AuthService
     private volatile boolean authSwitchMore;
     private volatile PluginName pluginName;
     private volatile long serverCapabilities;
+    private volatile boolean highPriority = false;
 
     public MySQLBackAuthService(BackendConnection connection, String user, String schema, String passwd, PooledConnectionListener listener, ResponseHandler handler) {
         super(connection);
+        if (handler instanceof HeartbeatSQLJob) {
+            highPriority = true;
+        }
         this.user = user;
         this.schema = schema;
         this.passwd = passwd;
@@ -59,6 +65,9 @@ public class MySQLBackAuthService extends BackendService implements AuthService
     // only for com_change_user
     public MySQLBackAuthService(BackendConnection connection, String user, String passwd, ResponseHandler handler) {
         super(connection);
+        if (handler instanceof HeartbeatSQLJob) {
+            highPriority = true;
+        }
         this.user = user;
         this.passwd = passwd;
         this.handler = handler;
@@ -294,8 +303,16 @@ public class MySQLBackAuthService extends BackendService implements AuthService
     }
 
 
-
     protected boolean isSupportFlowControl() {
         return false;
     }
+
+    @Override
+    protected Executor getExecutor() {
+        if (highPriority) {
+            return DbleServer.getInstance().getComplexQueryExecutor();
+        } else {
+            return DbleServer.getInstance().getBackendExecutor();
+        }
+    }
 }