diff --git a/infra/docker/entrypoint-worker.sh b/infra/docker/entrypoint-worker.sh
index 919bfc933..f2e208d96 100755
--- a/infra/docker/entrypoint-worker.sh
+++ b/infra/docker/entrypoint-worker.sh
@@ -6,8 +6,10 @@ set -e
 
 CONCURRENCY="${WORKER_CONCURRENCY:-2}"
 
-# 启用 -B 标志嵌入 celery beat（单 worker 实例，足够安全）
-# beat 负责定期触发 pending 超时清理等定时任务
+# ⚠️ 部署约束：此 Worker 必须且只能运行单实例（replicas=1）
+# -B 标志嵌入 celery beat，beat 负责定期触发 pending 超时清理等定时任务
+# 多实例部署会导致每个 Worker 独立运行 Beat，造成定时任务重复执行
+# 若需横向扩展 Worker，必须将 Beat 拆分为独立服务（celery beat -A worker_app.celery_app）
 exec celery \
   -A worker_app.celery_app \
   worker \
diff --git a/packages/adapters/sqlalchemy_impl/generation_task_repository.py b/packages/adapters/sqlalchemy_impl/generation_task_repository.py
index b9d318672..75f394edc 100755
--- a/packages/adapters/sqlalchemy_impl/generation_task_repository.py
+++ b/packages/adapters/sqlalchemy_impl/generation_task_repository.py
@@ -344,7 +344,7 @@ class SQLAlchemyGenerationTaskRepository:
                     GenerationTaskModel.error_info: error_info,
                     GenerationTaskModel.completed_at: datetime.now(timezone.utc),
                 },
-                synchronize_session="fetch",
+                synchronize_session=False,
             )
         )
         self.session.commit()