This topic describes how to modify the information about an origin server in the Alibaba
Cloud Content Delivery Network (CDN) console.
Background information
Notice When you modify the information about an origin server, if you set Origin Information to OSS Domain, IP, or Site Domain, you can specify a custom port that redirects requests to the origin server. If you
specify a custom port, Alibaba Cloud CDN redirects only HTTP requests to origin servers.
Alibaba Cloud CDN supports the following types of origin server: Object Storage Service
(OSS) endpoints, IP addresses of origin servers, domain names of origin servers, and
Function Compute domain names. If you set Origin Info to IP or Site Domain, you can
specify one or more IP addresses or domain names and set the priority for each IP
address or domain name.
Note Layer-4 health checks are performed on origin servers. Port 80, port 443, and custom
ports of origin servers are probed. Probes are sent every 2.5 seconds. If an origin
server fails three consecutive probes, the system marks the origin server as unavailable.
Alibaba Cloud CDN supports switchover between primary and secondary origin servers.
If multiple origin servers are configured, Alibaba Cloud CDN redirects requests to
the origin server whose Priority is Primary. If the primary origin server fails three consecutive probes, Alibaba Cloud CDN forwards
requests to the origin server whose Priority is Secondary. If the primary origin server passes a subsequent health check, the system marks
the origin server as available and restores the priority of this origin server to
primary. If you set the same priority for all origin servers, Alibaba Cloud CDN automatically
redirects requests to the origin servers based on the round robin scheme.