Symptoms

I use Alibaba Cloud Content Delivery Network (CDN) to accelerate the delivery of resources stored in an Object Storage Service (OSS) bucket. How is data transfer billed when CDN nodes retrieve resources from the OSS bucket?

Causes

When CDN nodes retrieve resources from OSS buckets, data transfer is billed based on the following rules:
  • When a CDN node retrieves resources from an OSS bucket, data is transmitted from the OSS bucket to the CDN node. In this case, Alibaba Cloud CDN does not charge fees but OSS does.
    Note
    • If the accelerated region is outside mainland China and an OSS bucket is used as the origin server, you are not charged for the data transferred from CDN nodes in the accelerated region to the origin server.
    • If the accelerated region is outside mainland China and an OSS bucket is used as the origin server, you are charged for the data transferred from CDN nodes in mainland China to the origin server.
    • If the accelerated region is in mainland China and an OSS bucket is used as the origin server, you are charged for the data transferred from CDN nodes outside mainland China to the origin server.
  • When the requested resources are already cached on the CDN node, data is transmitted from the CDN node to the client. In this case, OSS does not charge fees but Alibaba Cloud CDN does.

Example:

When a request is accelerated and redirected to OSS by the CDN node, data transfer is billed based on the amount of outbound traffic of Alibaba Cloud CDN generated by the acceleration service, and the amount of outbound traffic of OSS generated by the retrieval of the requested resource. For more information about the billing details of OSS, see Overview.