Introduction to Nginx Caching: Practical Tips for Improving Website Access Speed

Nginx caching temporarily stores frequently accessed content to "trade space for time," enhancing access speed, reducing backend pressure, and saving bandwidth. It mainly includes two types: proxy caching (for static resources in reverse proxy scenarios, with origin requests to the backend) and web caching (HTTP caching, relying on the backend `Cache-Control` headers for browser local caching). Dynamic content and frequently changing content (e.g., user information, real-time data) are not recommended for caching. Configuring proxy caching requires defining paths (e.g., `proxy_cache_path`) and parameters (e.g., cache size, key rules), enabling them in `location` (e.g., `proxy_cache my_cache`), and restarting Nginx after verifying the configuration. Management involves checking cache status (logging `HIT/MISS`), clearing caches (manually deleting cache files or using the `ngx_cache_purge` module), and optimization (caching only static resources, setting `max-age` reasonably). Common issues: For cache misses, check configuration, backend headers, or permissions; for stale content, verify `Cache-Control` headers. Key points: Cache only static content, monitor hit status via logs, and prohibit caching dynamic content.