Help Center/ Object Storage Service/ User Guide/ Domain Name Management/ Accessing a Bucket Using a CDN Acceleration Domain Name
Updated on 2025-08-26 GMT+08:00

Accessing a Bucket Using a CDN Acceleration Domain Name

Scenarios

More and more companies in various industries use OBS to store static resource files such as images, videos, and software packages, and use OBS as the storage source for websites, forums, apps, and games. These static resources can be obtained by accessing OBS through URLs. Generally, files are stored in only one region. If you access OBS far away from the region where files are stored, the response speed may be slow. In scenarios where frequent access is required, accessing OBS to obtain files consumes a large amount of traffic.

To improve the speed and stability for accessing static resource files, you can use CDN acceleration. If you have configured a user-defined domain name for a bucket, you can directly enable CDN acceleration for the domain name. If you have not configured a user-defined domain name for the bucket, you can configure a CDN acceleration domain name.

CDN acceleration applies to the following scenarios:

  • Website acceleration

    When static resources (such as images and files) on portals, e-commerce platforms, or user-generated content (UGC) apps are accessed by large or globally distributed user bases, CDN acceleration can make the responses faster.

  • Download acceleration

    CDN acceleration enables higher bandwidth and faster transmission, which reduces the time required for downloading files from websites, game clients, or app stores.

  • On-demand service acceleration

    In scenarios, such as online education and video sharing, that offer video on demand (VOD) and audio on demand (AOD) services, CDN acceleration can minimize playback buffering.

For details, see Application Scenarios.

Billing

CDN acceleration is billed once it is enabled. For details, see CDN Pricing Details. In addition, OBS provides pull traffic packages with discounts, so that you can spend less on traffic incurred by CDN acceleration.

Principles

Accessing OBS without CDN acceleration: Files are stored in only one region. Therefore, when a client accesses OBS far away from the region, the response speed may be slow.

Accessing OBS with CDN acceleration: When a client initiates a request, CDN searches for the CDN PoP that responds the fastest to the domain name and checks whether the CDN PoP has already cached the data requested by the client.

  • If cached, the CDN PoP returns the data to the client.
  • If not, the CDN PoP pulls the data from OBS, returns the data to the client, and caches the data on itself.

The CDN acceleration service can speed up response and improve user experience at low costs.

The following explains how a client accesses OBS without and with CDN acceleration.

Figure 1 shows the process of accessing OBS directly from clients without CDN acceleration.

Figure 1 Process of obtaining data from OBS

When a client initiates a request, CDN searches for the CDN PoP that responds the fastest to the domain name and detects that the requested data is not cached on the PoP. Then, the CDN PoP pulls the data from OBS, returns the data to the client, and caches the data on itself. Figure 2 shows the request process.

Figure 2 Accessing OBS with CDN acceleration (without cached data on the CDN PoP)

When a client initiates a request, CDN searches for the CDN PoP that responds the fastest to the domain name and detects that the requested data is cached on the PoP. Then, the CDN PoP returns the data to the client, without pulling data from OBS. Figure 3 shows the request process.

Figure 3 Accessing OBS with CDN acceleration (with cached data on the CDN PoP)

Constraints

Only buckets whose version is 3.0 or later support CDN acceleration. To check the version of a bucket, go to OBS Console, click the bucket name to go to the Overview page, and find the version in the Basic Information area.

Configuring an Acceleration Domain Name

You can only use OBS Console to configure acceleration domain names.

To configure an acceleration domain name on OBS Console, perform the following steps:

  1. Bind an acceleration domain name to the bucket.
  2. Add a CNAME record set to map the acceleration domain name to the default domain name of the bucket.

Enabling Acceleration for a User-Defined Domain Name

You can use OBS Console to enable acceleration for a user-defined domain name that has been configured for the bucket.

To enable acceleration, perform the following steps:

  1. Enable acceleration for the bound user-defined domain name.
  2. Add a CNAME record set to map the acceleration domain name to the default domain name of the bucket.