Content delivery networks (CDN) accelerate content distribution to end users by sending files from various other nodes (caching servers). Caching server networks resolve a variety of issues related to the quality and speed at which content is delivered to geographically distributed users and alleviate the workload on your primary server.
How It Works
When a user requests a file for the first time, that file is downloaded from the primary server to the CDN cache. For subsequent requests, this file will be sent to the user directly from the caching server.
Files are updated according to the cache settings. By default, a cache's lifetime is 24 hours. This means that every 24 hours, the CDN communicates with the source and checks to see if any cached files have been updated or changed. If they have, then the CDN downloads the latest version from the primary server.
Files that are not requested for an extended period of time are automatically deleted from the caching server. If a new request comes in, then the file is once again downloaded from the primary server.
|CDN resource||A set of parameters that let content sources refer to domains, from which users distribute content cached on a CDN provider's servers|
|CDN provider||The caching servers and software and hardware platform provided by a partner to accelerate content distribution|
|Content origin||The location where a CDN retrieves content. This is defined by a domain name or IP address|
|Default domain||A domain name, such as *.selcdn.net, that is created by default for every CDN resource. This allows content to be distributed over a CDN without a personal domain|
|Personal domain||A custom-defined domain name. Content can be distributed from this domain over a CDN|