CDN back-to-origin traffic refers to when a user requests to access content located on a CDN (Content Delivery Network) node. If the content is not cached on the node or the cached content has expired, the CDN will send a request to the origin server to obtain the original content, and transmit the content back to the CDN node through the network, and finally deliver it to the user. The amount of data transmission involved in this process is back-to-source traffic.
The main function of CDN is to cache content on nodes closer to users and provide fast and stable content transmission services. Back-to-origin traffic means that when the cache is invalid or missing, the CDN needs to obtain content from the origin server and then distribute it to users, which increases the load on the origin server and network bandwidth consumption.
The amount of back-to-origin traffic is related to factors such as cache hit rate, content update frequency, and distribution of user requests. Under normal circumstances, CDN will try to reduce the generation of return-to-origin traffic through technical means such as intelligent routing to improve overall performance and save costs.
