FastAPI Request Timeouts? A Guide to Asynchronous Processing and Performance Optimization

The essence of request timeouts in FastAPI is that the server processing time exceeds the client's waiting threshold. Common causes include user network lag, high server load, and interface-specific time-consuming operations (e.g., I/O operations), which can lead to poor user experience and request failures. Methods to set timeouts in FastAPI: At the route level, use the `timeout` parameter in `async def` functions (e.g., `@app.get("/slow-task", timeout=10)`); at the global level, implement via middleware (e.g., intercepting requests and setting `asyncio.wait_for` with a 10-second timeout). Asynchronous processing is key to improving speed: Asynchronous routes (`async def`) use `await` to call non-blocking operations (e.g., async database queries), while background tasks (`BackgroundTasks` or `asyncio.create_task`) handle non-immediate-return tasks (e.g., sending emails). Comprehensive performance optimization requires: Caching frequently accessed data (`lru_cache` or Redis), configuring database connection pools (e.g., `asyncpg`), optimizing databases (avoid N+1 queries, add indexes, batch operations), and deploying with multi-processing (Uvicorn multi-worker) or load balancing. Comprehensive optimization steps: Set reasonable timeout thresholds, process I/O-intensive tasks asynchronously, cache frequently accessed data, optimize database connections, and deploy appropriately.