Cache Consistency and Purging Across CDNs
Synopsis Caches remain consistent across providers only when cache keys, HTTP caching headers, immutable assets, purge methods, and deployment order express the same policy. Operational controls must detect partial propagation and provider-specific behavior before stale content reaches a wider audience. Purpose and scope Multi-CDN changes cache behavior because different networks fetch, store, and expire objects using different rules and clocks. The goal is that users receive the same bytes for the same URL regardless of the serving CDN and that changes reach users in a controlled and explainable way. The guidance applies to static assets and dynamic responses that allow caching. It also covers the surrounding systems that push and purge content. ...