Update create_engine method to include max_overflow parameter (#1341)

This pull request updates the `create_engine` method in the `DatabaseService` class to include the `max_overflow` parameter. This allows for better control of connection pooling and prevents connection errors when the pool is full. Additionally, it updates the `weaviate-client` version to `4.0.0` and the `langflow` version to `0.6.5a4`.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "langflow"
-version = "0.6.5a3"
+version = "0.6.5a4"
 description = "A Python package with a built-in web application"
 authors = ["Logspace <contact@logspace.ai>"]
 maintainers = [
@@ -55,7 +55,7 @@ tiktoken = "~0.5.0"
 wikipedia = "^1.4.0"
 qdrant-client = "^1.7.0"
 websockets = "^10.3"
-weaviate-client = "^3.26.0"
+weaviate-client = "^4.0.0"
 jina = "*"
 sentence-transformers = { version = "^2.2.2", optional = true }
 ctransformers = { version = "^0.2.10", optional = true }

src/backend/langflow/services/database/service.py

@@ -5,17 +5,16 @@ from typing import TYPE_CHECKING
 import sqlalchemy as sa
 from alembic import command, util
 from alembic.config import Config
-from loguru import logger
-from sqlalchemy import inspect
-from sqlalchemy.exc import OperationalError
-from sqlmodel import Session, SQLModel, create_engine, select, text
-
 from langflow.services.base import Service
 from langflow.services.database import models  # noqa
 from langflow.services.database.models.user.crud import get_user_by_username
 from langflow.services.database.utils import Result, TableResults
 from langflow.services.deps import get_settings_service
 from langflow.services.utils import teardown_superuser
+from loguru import logger
+from sqlalchemy import inspect
+from sqlalchemy.exc import OperationalError
+from sqlmodel import Session, SQLModel, create_engine, select, text
 
 if TYPE_CHECKING:
     from sqlalchemy.engine import Engine
@@ -40,7 +39,7 @@ class DatabaseService(Service):
             connect_args = {"check_same_thread": False}
         else:
             connect_args = {}
-        return create_engine(self.database_url, connect_args=connect_args)
+        return create_engine(self.database_url, connect_args=connect_args, max_overflow=-1)
 
     def __enter__(self):
         self._session = Session(self.engine)