NGINX caching is a feature of the NGINX web server that stores copies of requested content in a cache, allowing faster retrieval for future requests. This can significantly improve performance, reduce the load on backend servers, and enhance the overall user experience by delivering content quickly.
Here’s how it works:
Key Concepts of NGINX Caching:
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Cache Layer: When a user requests content (e.g., a webpage or image), NGINX checks if that content is stored in its cache. If it is, the cached version is served (a "cache hit"). If not, NGINX fetches the content from the backend server, delivers it to the user, and then stores it in the cache (a "cache miss").
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Expiration and Purging: Cached content can be set to expire after a specific time (e.g., 1 hour, 24 hours) or purged manually. This ensures that users always receive fresh content without overwhelming the server.
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Types of Caching:
- Static Content Caching: This includes files that don’t change frequently, such as CSS, JavaScript, and images.
- Dynamic Content Caching: NGINX can also cache dynamically generated content (like HTML from PHP applications) to improve performance for frequently visited pages.
Benefits of NGINX Caching:
- Improved Load Times: Cached responses are served much faster than fetching them from the backend, reducing the time users wait for pages to load.
- Reduced Server Load: By serving cached content, NGINX reduces the number of requests to the backend, freeing up server resources for other tasks.
- Lower Bandwidth Consumption: Since cached responses are delivered directly from the server’s cache, there's less data that needs to be transferred from backend servers.
