If you change the acceleration region, the back-to-origin traffic may increase and the hit rate may decrease.
When the acceleration region is changed from mainland China to global, CDN nodes outside mainland China are added, and these nodes have not cached the resources from your origin server. Therefore, when you access these new nodes, they can only retrieve resources from your origin server. This results in an increase in the back-to-origin traffic in a short period of time. At the same time, the overall node hit rate is reduced.
If the back-to-origin traffic increases, you must pay attention in real time to check whether your origin server can withstand the increased back-to-origin traffic. Alibaba Cloud CDN L2 nodes can greatly minimize the back-to-origin traffic. However, to prevent possible risks, we recommend that you pay attention to the pressure on your origin server after you change the acceleration region. If an issue occurs, submit a ticket.