We suggest you using several origins to improve failure-resistance of your service (only for IP-
format origins, up to 3 IPs). Please ensure that your origin is configured to accept HTTP requests from CDN servers with CDN Resource primary CNAME as a Host header.
Round-robin algorithm is used by CDN while choosing an origin to pull the content from. If one of origins becomes unavailable, CDN will automatically requests content from other available origins.
Note! If all origins are available but a specific file becomes unavailable, CDN will not request this file from other origins but return an error to an end user.