Guides

A cache key decides whether two requests may reuse the same stored response. A typical CDN starts with the request scheme, host, path, and query string. It may also include selected headers or cookies. The Vary response header is the HTTP mechanism that tells a cache which request headers selected a representation. The safe goal is simple: requests that should receive the same bytes should share a key, while requests that require different bytes must not collide. A key that is too narrow can expose the wrong response. A key that is too broad creates many variants, lowers the cache hit ratio , and increases origin traffic. ...

No. Hetzner does not provide a native content delivery network. Hetzner’s Object Storage FAQ explicitly says that Object Storage is not a CDN and recommends placing a third-party CDN in front of it for large-scale global delivery. Hetzner can still be the origin. A CDN can fetch files from Hetzner Object Storage, a cloud server, a dedicated server, or a load-balanced application and cache suitable responses at its edge locations. ...

Multi-CDN is a strategy that uses more than one CDN at the same time. Instead of relying on a single provider, traffic flows through multiple networks and is steered to whichever one works best at that moment. This approach improves reach, resilience, and sometimes cost efficiency. If you are unfamiliar with the basics of CDNs, see the Top 10 Questions About CDNs first. 1. What is a Multi-CDN and how does it differ from a single CDN? A single CDN depends on one provider’s network of points of presence . A Multi-CDN combines the reach of several providers, switching between them based on performance, location, or availability. The result is fewer single points of failure and a smoother experience for global audiences. ...

Content Delivery Networks , or CDNs, keep much of the modern web running smoothly. They are behind faster page loads, fewer outages, and safer browsing experiences. If you have wondered how they work or whether you should use one, here are the ten questions people ask most - with answers in plain language. For more advanced strategies that combine multiple providers, see the Top 10 Questions About Multi-CDN . 1. What is a CDN and how does it work? A CDN is a network of servers in many locations. It stores copies of website content on those servers so they can be delivered from a place closer to the visitor. Instead of every request going back to the main origin server, a CDN routes the visitor to the nearest edge server. The shorter the journey, the faster the response. ...

Caching is one of the simplest ways to improve delivery. A cache saves a copy of a response so it can be served without a round trip to the origin . The core control surface is the Cache-Control header and the time-to-live (TTL ). Freshness and validation determine when a cache can reuse a stored response and when it must contact the origin. Quick answers max-age sets freshness for private and shared caches. s-maxage overrides max-age in a shared cache such as a CDN. It does not change the browser’s freshness lifetime. Vary tells a cache which request headers selected the response. Each meaningful value can create a separate representation. Vary: * prevents normal reuse because the cache cannot prove that a later request is equivalent. no-cache allows storage but requires validation before reuse. no-store prohibits storage. Freshness vs validation A cache serves a response when it is fresh. Freshness comes from an explicit lifetime such as max-age or from an older Expires date. After freshness ends, a cache either revalidates or fetches again. ...