fix(api): use plain Session in RAG pipeline controllers to prevent closed-transaction error (#36392)

api/controllers/console/datasets/rag_pipeline/rag_pipeline_datasets.py

@@ -1,6 +1,6 @@
 from flask_restx import Resource, marshal
 from pydantic import BaseModel
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import Session
 from werkzeug.exceptions import Forbidden
 
 import services
@@ -54,12 +54,13 @@ class CreateRagPipelineDatasetApi(Resource):
             yaml_content=payload.yaml_content,
         )
         try:
-            with sessionmaker(db.engine).begin() as session:
+            with Session(db.engine, expire_on_commit=False) as session:
                 rag_pipeline_dsl_service = RagPipelineDslService(session)
                 import_info = rag_pipeline_dsl_service.create_rag_pipeline_dataset(
                     tenant_id=current_tenant_id,
                     rag_pipeline_dataset_create_entity=rag_pipeline_dataset_create_entity,
                 )
+                session.commit()
             if rag_pipeline_dataset_create_entity.permission == "partial_members":
                 DatasetPermissionService.update_partial_member_list(
                     current_tenant_id,

api/controllers/console/datasets/rag_pipeline/rag_pipeline_import.py

@@ -1,7 +1,7 @@
 from flask import request
 from flask_restx import Resource, fields, marshal_with  # type: ignore
 from pydantic import BaseModel, Field
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import Session
 
 from controllers.common.schema import get_or_create_model, register_schema_models
 from controllers.console import console_ns
@@ -67,10 +67,12 @@ class RagPipelineImportApi(Resource):
         current_user, _ = current_account_with_tenant()
         payload = RagPipelineImportPayload.model_validate(console_ns.payload or {})
 
-        # Create service with session
-        with sessionmaker(db.engine).begin() as session:
+        # Use a plain Session so that caught exceptions inside the service
+        # (which return FAILED status instead of re-raising) do not leave the
+        # transaction in a closed state that a .begin() context manager cannot
+        # handle.  See app_import.py for the canonical pattern.
+        with Session(db.engine, expire_on_commit=False) as session:
             import_service = RagPipelineDslService(session)
-            # Import app
             account = current_user
             result = import_service.import_rag_pipeline(
                 account=account,
@@ -80,6 +82,10 @@ class RagPipelineImportApi(Resource):
                 pipeline_id=payload.pipeline_id,
                 dataset_name=payload.name,
             )
+            if result.status == ImportStatus.FAILED:
+                session.rollback()
+            else:
+                session.commit()
 
         # Return appropriate status code based on result
         status = result.status
@@ -102,12 +108,14 @@ class RagPipelineImportConfirmApi(Resource):
     def post(self, import_id):
         current_user, _ = current_account_with_tenant()
 
-        # Create service with session
-        with sessionmaker(db.engine).begin() as session:
+        with Session(db.engine, expire_on_commit=False) as session:
             import_service = RagPipelineDslService(session)
-            # Confirm import
             account = current_user
             result = import_service.confirm_import(import_id=import_id, account=account)
+            if result.status == ImportStatus.FAILED:
+                session.rollback()
+            else:
+                session.commit()
 
         # Return appropriate status code based on result
         if result.status == ImportStatus.FAILED:
@@ -124,7 +132,7 @@ class RagPipelineImportCheckDependenciesApi(Resource):
     @edit_permission_required
     @marshal_with(pipeline_import_check_dependencies_model)
     def get(self, pipeline: Pipeline):
-        with sessionmaker(db.engine).begin() as session:
+        with Session(db.engine, expire_on_commit=False) as session:
             import_service = RagPipelineDslService(session)
             result = import_service.check_dependencies(pipeline=pipeline)
 
@@ -142,7 +150,7 @@ class RagPipelineExportApi(Resource):
         # Add include_secret params
         query = IncludeSecretQuery.model_validate(request.args.to_dict())
 
-        with sessionmaker(db.engine).begin() as session:
+        with Session(db.engine, expire_on_commit=False) as session:
             export_service = RagPipelineDslService(session)
             result = export_service.export_rag_pipeline_dsl(
                 pipeline=pipeline, include_secret=query.include_secret == "true"

api/services/rag_pipeline/rag_pipeline_dsl_service.py

@@ -78,9 +78,9 @@ class CheckDependenciesPendingData(BaseModel):
 class RagPipelineDslService:
     """Import, export, and inspect RAG pipeline DSL using the caller-owned session.
 
-    Controllers wrap this service in a SQLAlchemy transaction context, so methods must only flush interim changes when
-    generated IDs are needed. Committing inside the service would close the caller's transaction and break later work in
-    the same context manager.
+    Callers pass a plain ``Session`` (not wrapped in ``.begin()``) and are responsible for calling
+    ``session.commit()`` on success or ``session.rollback()`` on failure.  Methods here only flush
+    when generated IDs are needed mid-operation; they never commit or rollback.
     """
 
     def __init__(self, session: Session):