How to ensure flawless site work in case of endless torrent of requests from several Points of Presence coming to the origin servers? One of the most reliable methods is origin shielding.
What is CDN origin shielding?
This is one of the latest CDN technologies, a service that readdresses end-users’ request from customer origin server to another point of presence and a secondary PoP serving for failover situations. It decreases the load on origin server by getting the requests from a special data center also called “shield” usually located near your origin. Thus, multiple data centers of the network do not have to request the same data from origin.
The main idea of this server is to make the client receive fewer requests for content from the CDN, because similar requests are de-duplicated, and content is served from CDN cache. When Origin Shielding is activated, CDN will send a request for content from customer’s origin server if the shield PoP does not have this content requested before. Even in this case less load and bandwidth are exploited from your origin. Besides, origin shielding can also help to save on origin egress costs considerably.
How to configure the “Shield PoP”
If your provider supports such function, Origin Shielding may be customized and configured by an admin user within an Origin Pull Policy. Besides, many supply various tools for testing network performance from a certain point of presence (PoP) to the original server (for instance, Barometer from Highwinds). Due to that function, you can figure up an optimal origin for the most effective PoP for your origin.
As a rule, CDN companies offer only one PoP that can serve as the shield on the network. Requests are sent back to the origin server, which protects the origin from numerous requests for the same content from different locations.