How can I handle sudden spikes in traffic on a Flask application using Gunicorn?
I have a Flask application that serves a small user base, but I recently launched a marketing campaign that has resulted in a sudden spike in traffic... I'm currently using Gunicorn with the default worker settings, and I've noticed that my application starts throwing `502 Bad Gateway` errors when the number of concurrent requests exceeds about 20. My current Gunicorn command looks like this: ```bash gunicorn -w 2 -b 0.0.0.0:8000 myapp:app ``` I’ve tried increasing the number of workers to 4 using `-w 4`, but it didn’t seem to help as the application still crashes under load. My server has 2 CPUs, and I’m using an SQLite database, which I suspect might be a bottleneck as well. I've read that SQLite isn't ideal for production workloads, but I’m not sure if switching to PostgreSQL will solve my concurrency issues. I also implemented basic caching using Flask-Caching, but I’m not seeing important improvements, especially on pages that require database access. Here’s how I configured it: ```python from flask_caching import Cache cache = Cache(app, config={'CACHE_TYPE': 'simple'}) @app.route('/data') @cache.cached(timeout=60) def get_data(): # Simulate a database call # Printing to check how many times this gets called print("Fetching data...") return "Data" ``` Could anyone provide guidance on how to handle these spikes more effectively? Should I be considering a different database setup or optimizing Gunicorn’s configuration? Are there any best practices for scaling Flask applications that you would recommend? My development environment is Linux. Is this even possible? I'm working in a macOS environment. Am I missing something obvious?