diff --git a/main.py b/main.py
index 63954e3..73f0df2 100644
--- a/main.py
+++ b/main.py
@@ -163,10 +163,11 @@ def integrate_data_parallel():
             time.sleep(10)
             continue
 
-        futures = [
-            executor.submit(search_worker, payload, kitem, flag)
-            for payload, kitem in tasks
-        ]
+        futures = []
+        for payload, kitem in tasks:
+            futures.append(executor.submit(search_worker, payload, kitem, flag))
+            time.sleep(3)
+
         rollback = {0: [], 1: [], 2: []}
 
         for fut in concurrent.futures.as_completed(futures):
@@ -209,7 +210,6 @@ def integrate_data_parallel():
             db.rollback_l1(rollback[1])
         if rollback[2]:
             db.rollback_l2(rollback[2])
-        time.sleep(10)
 
 
 def parse_args() -> argparse.Namespace: