CDNcaches

CDNcaches are caching components used within content delivery networks to store copies of web content at distributed edge locations, with the goal of reducing latency and origin-server load. By serving content from geographically closer servers, CDNcaches typically provide faster responses and lower bandwidth usage, especially during traffic surges.

Operation typically follows a simple edge-to-origin workflow. When a user requests a resource, the edge cache checks its local store. If a valid copy is present (a cache hit), the resource is served directly. If not (a cache miss), the edge fetches the content from the origin or another cache, stores the response according to the configured time-to-live, and serves it to the user. This behavior is governed by caching policies and the configured cache keys.

Caching policy and control rely on HTTP headers and CDN-specific rules. Cache-Control, Max-Age, and Vary influence whether a response is cacheable and under what conditions it may be served. Some CDNcaches support advanced features such as stale-while-revalidate or edge-side dynamic caching to extend usefulness for dynamic content. Cache invalidation can be performed by purging, by updating resource URLs (cache busting), or by conditional revalidation using If-Modified-Since or If-None-Match.

Impact and considerations include significant performance gains and reduced origin load, balanced against privacy and security concerns. Edge caching may affect cookie handling, TLS termination, and cache integrity, making correct cache-key design, HTTPS configuration, and cache purging practices important to avoid stale data or inadvertent data leakage.

Common use cases cover static assets, media files, software updates, and other content with high request volume that benefits from edge delivery.