Alibaba Cloud CDN and Object Storage Service (OSS) bill you separately when Alibaba Cloud CDN accelerates content that is stored in an OSS bucket. This topic describes the fee items that each service charges, how each data flow between clients, CDN points of presence (POPs), and an OSS bucket is priced, and which resource plans offset those fees.
Billable items
Alibaba Cloud CDN and OSS meter only their own resources, and the rates of the two services differ. For rates, see Alibaba Cloud CDN pricing and OSS pricing.
The following table lists the fee items that apply when your origin server is an OSS bucket. This topic explains only how data transfer is charged. For the metering rules of the other fee items, see the Billing overview topic of the service that charges them.
Billable item | Description |
Alibaba Cloud CDN service fee | Outbound data transfer is charged in most cases. In specific cases, other items such as the fee for each HTTPS request for static content may also apply. For details, see Billing overview. |
OSS service fee | Data storage fee is charged in most cases. In specific cases, other items such as OSS requests may also apply. For details, see Billing overview. |
How data transfer is charged
Three data flows occur when your origin server is an OSS bucket. Each flow follows a different billing rule.
Data flow | Direction | Charged by | Fee item |
Flow 1 | CDN POPs to clients | Alibaba Cloud CDN | Outbound data transfer |
Flow 2 | CDN POPs to OSS (origin fetch request) | None | — |
Flow 3 | OSS to CDN POPs (content returned during an origin fetch) | OSS | Back-to-origin traffic |
The following figure shows the data flows between clients, CDN POPs, and an OSS bucket.
An origin fetch consists of Flow 2 and Flow 3. Alibaba Cloud CDN charges for neither direction of an origin fetch, whereas OSS meters the content that it returns to CDN POPs in Flow 3. The OSS rate for Flow 3 is not fixed: the traffic can be free of charge, priced at a preferential rate, or priced at the standard rate. For the conditions of each rate, see OSS pricing for data returned to CDN POPs.
For Alibaba Cloud CDN rates for Flow 1, see Alibaba Cloud CDN pricing. For OSS rates for Flow 3, see OSS pricing - Data transfer to CDN.
OSS pricing for data returned to CDN POPs
The rate that OSS applies to the back-to-origin traffic in Flow 3 depends on two factors: where the CDN POP and the OSS bucket are located, and which origin server type is configured in the Alibaba Cloud CDN console. The following table lists the resulting rates.
Location of the CDN POP and the OSS bucket | Origin server type in the CDN console | OSS rate for back-to-origin traffic |
Both outside the Chinese mainland | — | Free of charge. |
The CDN POP, the OSS bucket, or both in the Chinese mainland | OSS domain (recommended) | Preferential pricing. OSS identifies the traffic as back-to-origin traffic from Alibaba Cloud CDN. |
The CDN POP, the OSS bucket, or both in the Chinese mainland | Origin domain name | Standard pricing. OSS identifies the traffic as outbound data transfer over the Internet. |
(Recommended) To qualify for preferential pricing, set the origin server type to OSS Domain when you Add Origin Server in the Alibaba Cloud CDN console. For instructions on using an OSS bucket as the origin server, see Accelerate the retrieval of resources from an OSS bucket.
If you set the origin server type to Origin Domain Name by mistake, OSS meters this traffic as outbound data transfer over the Internet and the preferential rate no longer applies.
Resource plans
Alibaba Cloud CDN resource plans offset Alibaba Cloud CDN fees, and OSS resource plans offset OSS fees. Purchase the plan for each service separately. Usage beyond the quota of a plan is billed on a pay-as-you-go basis.
Resource plan | Fee that it offsets |
Outbound data transfer from CDN POPs to clients (Flow 1). | |
Alibaba Cloud CDN plan for HTTPS requests for static content | HTTPS requests for static content. |
Back-to-origin traffic that OSS returns to CDN POPs (Flow 3). | |
Storage capacity of Standard locally redundant storage (LRS). |