Handling Memory Leaks in Async FastAPI Applications Using Database Connections
I'm reviewing some code and Hey everyone, I'm running into an issue that's driving me crazy. I'm developing a FastAPI application that uses SQLAlchemy for database interactions, and I've noticed that the application consumes more memory over time, suggesting a memory leak. Specifically, when handling multiple concurrent requests, the memory usage increases significantly, and eventually, the application crashes with an `Out of Memory` behavior. I suspect that the scenario may be related to how I'm managing the database sessions. Here’s a simplified version of my code: ```python from fastapi import FastAPI, Depends from sqlalchemy.orm import Session, sessionmaker from sqlalchemy import create_engine, Column, Integer, String from sqlalchemy.ext.declarative import declarative_base DATABASE_URL = "sqlite:///./test.db" engine = create_engine(DATABASE_URL) Base = declarative_base() class User(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True, index=True) name = Column(String, index=True) SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine) app = FastAPI() async def get_db(): db = SessionLocal() try: yield db finally: db.close() @app.post("/users/") async def create_user(name: str, db: Session = Depends(get_db)): db_user = User(name=name) db.add(db_user) db.commit() db.refresh(db_user) return db_user ``` I have ensured that I'm closing the database sessions in the `finally` block, but the memory usage keeps increasing. I also tried using connection pooling with `create_async_engine`, but the scenario continues. I'm running FastAPI version 0.65.1 and SQLAlchemy version 1.4.22. Is there something I might be overlooking in my implementation, or could there be an scenario with the way I'm using async functions with the SQLAlchemy session? Any guidance on how to debug this would be greatly appreciated! How would you solve this? This issue appeared after updating to Python 3.10. Has anyone dealt with something similar? I'm coming from a different tech stack and learning Python.