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Set priorities for origin sites

Last Updated: Aug 08, 2019


Alibaba Cloud CDN supports three types of back-to-origin domains: OSS back-to-origin domain, IP address domain, and custom domain. Also, multiple IP addresses and custom domains are supported. If multiple origin sites exist, you can configure back-to-origin priorities for them.

When the back-to-origin type is IP address domain or custom domain, you can set multiple origin sites and configure their priorities. You can set the priority to primary or backup, where primary is prior to backup.

All back-to-origin traffic is directed to the origin site with the highest priority. If an origin site fails the health check three consecutive times, all traffic is directed to the origin site with a lower priority. If the origin site passes the health check, it is marked as Available again and its priority is reclaimed. If all origin sites have the same back-to-origin priority, CDN round-robin applies.

Origin site health check: A Layer-4 health check is automatically conducted on origin sites every five seconds.

Scenario: Primary/backup origin site switchover


  1. Go to the Domain Names page, select the target domain name, and click Configure.
  2. Choose Basic Configuration > Origin Information, click Modify and set the origin site type, address, and port. The supported back-to-origin ports include port 80, port 443, and custom ports.

    • If you select an IP address domain or origin-site domain, the traffic is billed based on the Internet traffic pricing plan.

    • If you select an OSS domain, namely, from CDN to OSS, the traffic is billed based on the internal network traffic pricing plan. For more information, seeOSS Pricing

    • If you select an origin-site domain and set an OSS domain, the traffic is billed based on the Internet traffic pricing plan.

      Back-to-origin basic configuration

  3. After configuring the preceding settings, click Confirm.

    Note:The multi-origin priority setting is only applicable to the IP address and origin-site domains. You can select origin site types and set the priorities as needed. The origin site setting cannot be applied to live streaming acceleration.

Set custom ports

After activating the whitelist, you can set a custom port. The range of supported port numbers is 0 to 65535.

  • You cannot set a custom port when your static or dynamic protocol is set to Follow.
  • If you set the back-to-origin protocol to Use Request Protocol for Back-to-Origin through the API, make sure that the back-to-origin protocol and custom port are working properly.
  • If you use a port to set a back-to-origin protocol (HTTP or HTTPS) and a custom port, the port configuration prevails over the console configuration.