What is the index of CDN hit rate? What are the general indicators of traffic hit rate and request hit rate?

The hit rate of CDN refers to the probability of hitting the cache when users visit.

When a user accesses a domain name using a CDN, the request will be resolved to a CDN node. At this point:

If the content requested by the user has been cached on the CDN node, it will be returned directly. (This counts as a hit in the cache)

If the corresponding content is not cached on the CDN node, it will immediately go to the source station to get it, and then return it to the visitor, and cache the content on the node. (So there is no cache hit)

To sum up, the higher the cache hit rate, the fewer times it returns to the source, and the better the acceleration effect.