feat: optimize db connections in thread (#1601)

api/services/completion_service.py

@@ -232,7 +232,7 @@ class CompletionService:
                 logging.exception("Unknown Error in completion")
                 PubHandler.pub_error(user, generate_task_id, e)
             finally:
-                db.session.commit()
+                db.session.remove()
 
     @classmethod
     def countdown_and_close(cls, flask_app: Flask, worker_thread, pubsub, detached_user,
@@ -242,6 +242,7 @@ class CompletionService:
 
         def close_pubsub():
             with flask_app.app_context():
+                try:
                     user = db.session.merge(detached_user)
 
                     sleep_iterations = 0
@@ -258,6 +259,8 @@ class CompletionService:
                             pubsub.close()
                         except Exception:
                             pass
+                finally:
+                    db.session.remove()
 
         countdown_thread = threading.Thread(target=close_pubsub)
         countdown_thread.start()
@@ -394,7 +397,7 @@ class CompletionService:
                     logging.exception(e)
                     raise
             finally:
-                db.session.commit()
+                db.session.remove()
 
                 try:
                     pubsub.unsubscribe(generate_channel)
@@ -436,7 +439,7 @@ class CompletionService:
                         logging.exception(e)
                         raise
                 finally:
-                    db.session.commit()
+                    db.session.remove()
 
                     try:
                         pubsub.unsubscribe(generate_channel)