Overview

When a user requests content on an acceleration domain name, and the content is not cached on CDN PoPs, CDN PoPs will pull the content from the origin server. You can set origin parameters based on your needs to speed up access.

CDN Origin Pull Principle

An end user initiates a request when visiting a website. DNS resolution points the URL requested by the client (such as a browser) to the acceleration domain name.
The CDN PoP searches the cache. If the resource has been cached on the CDN PoP, the PoP returns the resource to the client.
The CDN PoP initiates a pull request to the origin server based on the origin pull policy of the domain name if the requested resource is not cached on the PoP.
The origin server returns the requested resource to the PoP based on the requested URL and parameters.
The PoP returns the resource to the client. It also caches the resource for future requests from clients.

Supported Configuration Items

You can modify origin settings of a domain name that is in the Enabled or Configuring state and is not locked or banned.

Function	Description
Origin Protocol	You can configure the request protocol used by CDN for origin pull.
Origin SNI	If your origin server IP address is bound to multiple domains and CDN visits the origin server using HTTPS, you can set the SNI to specify the domain to be visited by CDN during origin pull.
Origin URL Rewriting	If the URLs of origin pull requests do not match the origin server URLs, you can rewrite the request URLs to improve the origin pull hit ratio.
Advanced Origins	You can configure advanced origins to allow CDN to pull content from different origin servers based on different resource types or paths.
Range Requests	You can allow CDN to pull large files from the origin server by range and return ranges to users, speeding up distribution and reducing bandwidth consumption.
Redirect from Origin	If your origin server uses a 301/302 redirect, you can enable redirect from origin to cache the redirected resources on CDN PoPs for accelerated distribution.
ETag Verification	If your resources on the origin server remain unchanged and you do not want CDN to pull the resources after the cache expires, you can enable ETag verification.
Origin Response Timeout	You can adjust the origin response timeout based on the features and service scenarios of your origin server.
Origin Request Headers	You can rewrite headers in users' request URLs for origin pull.