When Alibaba Cloud CDN accelerates the delivery of static resources to a user, it retrieves the resources from the origin server and caches them on the CDN edge node that is nearest to the user. When the resources are requested again, the CDN edge node directly returns the cached resources to the user. This accelerates content delivery. All the edge nodes of Alibaba Cloud CDN are equipped with a caching system. When a user or an origin server interacts with an edge node, the caching system responds to user requests or processes responses from the origin server. For example, the caching system specifies a time-to-live (TTL) for cached resources or rewrites back-to-origin requests.

Related features

The following table describes the operations that you can perform on a domain name by using the caching feature.
Feature Description
Add a cache expiration rule Allows you to configure cache expiration rules for static resources in a specified directory or with specified file extensions. In each cache expiration rule, you can set a TTL for the cached static resources and a priority for the rule. CDN edge nodes cache and expire static resources based on the cache expiration rules.
Create a cache expiration rule for HTTP status codes Allows you to set a TTL for HTTP status codes that are returned to requests for resources in a specified directory or with specified file extensions.
Create a custom HTTP response header Allows you to customize HTTP response headers for expired resources.
Create a custom error page Allows you to customize an error page for a specific HTTP status code.
Create a URI rewrite rule Allows you to rewrite URIs in requests and perform 302 redirects to redirect the requests to the destination URIs.
Custom cache keys Allows you to set a cache key for a type of request that is destined for the same resource file. This can help you save the cache space and reduce the number of requests redirected to the origin server.
Configure CORS Allows you to implement cross-origin resource sharing (CORS) by using custom HTTP response headers.

Best practices

For more information about how to configure Alibaba Cloud CDN by using WordPress, see Accelerate content delivery for infographic and video websites.