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What is NGINX Caching?

Table of Contents
  1. Client Request: NGINX intercepts a user’s request to a website.

  2. Cache Check: It then checks if the requested content resides in its cache. If a match is found, NGINX promptly serves the content from the cache, bypassing the backend server.

  3. Cache Miss: In the event of a cache miss (when content isn’t in the cache), NGINX forwards the request to the backend server for retrieval.

  4. Cache Population: After obtaining the content from the backend, NGINX caches a copy for potential future requests

  5. Content Delivery: NGINX then delivers the requested content to the client.

  6. Cache Expiry and Invalidation: Cached content may have a predefined expiry, prompting NGINX to revalidate it with the backend. Additionally, content can be deliberately invalidated if it’s deemed obsolete.

Types of NGINX Caching

  1. Proxy Cache: This variant caches responses from a proxied server, proving invaluable for content from upstream servers like application servers.

  2. FastCGI Cache: When NGINX serves as a FastCGI proxy, it caches responses from FastCGI applications.

  3. Static File Cache: NGINX adeptly caches static files (e.g., images, CSS, JavaScript) for swift direct delivery without backend involvement.

  4. HTTP Caching Directives: NGINX supports HTTP caching directives, encompassing headers like Cache-Control and Expires, to regulate how browsers and intermediaries cache content.

Optimizing Performance with NGINX Caching

Implementing NGINX caching yields substantial enhancements in web application performance. It alleviates the strain on backend servers, leading to expedited response times for clients. However, meticulous configuration is imperative to avert inadvertent caching of dynamic content and ensure timely refreshment of stale content.

In summary, NGINX caching is a pivotal facet of web performance optimization, leveraging NGINX’s robust capabilities to enhance user experience and website efficiency. By intelligently storing and serving frequently accessed content, it significantly reduces server load and improves response times. With prudent configuration, NGINX caching can be a powerful tool in optimizing web applications.