When you need to transfer data over long distances, transfer acceleration provides end-to-end acceleration for uploads and downloads, using a global network of access points and intelligent routing. It addresses issues such as high latency and network instability during cross-region data transfers, significantly improving transfer speeds and user experience.
How it works
Transfer acceleration resolves network latency and instability common in long-distance access to Object Storage Service (OSS) through intelligent access point selection. When you access a bucket through an acceleration endpoint, the system automatically routes the request to the nearest Alibaba Cloud access point. Data then travels at high speed over Alibaba Cloud's optimized internal network to the target bucket's region.
By shortening the "first mile" from the user to the Alibaba Cloud network, transfer acceleration avoids routing data over long, congested internet paths. For example, consider a user in Japan accessing a bucket in the Chinese mainland. A request to the bucket's public endpoint would travel the entire distance through the complex, multi-hop public internet. In contrast, a request to the acceleration endpoint connects the user to a local Alibaba Cloud access point in Japan. The data then travels directly to the bucket in the Chinese mainland through Alibaba Cloud's dedicated global backbone network. This approach significantly reduces the transmission distance on the unstable public network, improving transfer stability and speed.
Two types of acceleration endpoints are provided for different compliance requirements:
Global acceleration endpoint:
oss-accelerate.aliyuncs.com, which enables intelligent acceleration across all regions.Acceleration endpoint for regions outside the Chinese mainland:
oss-accelerate-overseas.aliyuncs.com, which uses access points located outside the Chinese mainland. Use it when you map a domain without an ICP filing to a bucket in Hong Kong (China) or another overseas region by using a CNAME record.
Enable access through transfer acceleration
Step 1: Enable transfer acceleration
After you enable transfer acceleration, the bucket's original endpoints, such as the public endpoint, remain fully functional. This lets your application choose the optimal access method based on user location and network conditions.
Go to the Buckets page and click the name of the target bucket.
In the left-side navigation pane, click .
Turn on the Transfer Acceleration toggle, read the prompt in the dialog box that appears, then click OK.
Step 2: Verify access
Choose a verification method based on the bucket's access control list (ACL) settings.
Public-read or public-read-write buckets
Access the object directly through its URL in a browser. For example, https://example-bucket.oss-accelerate.aliyuncs.com/dest.jpgaccesses the dest.jpg file in the example-bucket Bucket.
Private buckets
To access a private bucket, you must include signature information in the object URL. The following steps show how to obtain a signed URL for an object from the console. For detailed information about how to generate signatures, see Signature Version 4 (recommended).
Go to the Buckets page and click the name of the target bucket.
In the Actions column for the target object, click View Details.
Click Copy Object URL and replace the public endpoint in the URL with the acceleration endpoint.
Access the modified URL in your browser.
Step 3: Test the performance
The following test compares the download speed of an object from a bucket in the China (Hangzhou) region to an ECS instance in the Japan (Tokyo) region using ossutil.
Before you start, install and configure ossutil 2.0.
Without acceleration
ossutil cp oss://example-bucket/ossutil-2.1.2-mac-arm64.zip ossutil-2.1.2-mac-arm64.zip -e oss-cn-hangzhou.aliyuncs.comThe download time is as follows:
Success: Total 1 object, size 9281195 B, Download done:(1 files, 9281195 B), avg 8.733 MiB/s 1.013983(s) elapsedWith acceleration
ossutil cp oss://example-bucket/ossutil-2.1.2-mac-arm64.zip ossutil-2.1.2-mac-arm64.zip -e oss-accelerate.aliyuncs.comThe download time is as follows:
Success: Total 1 object, size 9281195 B, Download done:(1 files, 9281195 B), avg 20.155 MiB/s 0.440160(s) elapsed
Apply in production
Best practices
Combine CDN with Transfer Acceleration: A multilayer acceleration architecture
You can configure both CDN acceleration and transfer acceleration simultaneously. By setting the CDN Origin to the acceleration endpoint, you create a dual-layer acceleration system that combines CDN edge caching with transfer acceleration. The CDN serves user requests from the nearest cache, while transfer acceleration optimizes the CDN's origin-fetch path. This architecture is ideal for globally distributed static assets, achieving full-path optimization for both cache hits and origin fetches.
Optimize large file transfers: Combine multipart transfer with acceleration
For transferring gigabyte- or terabyte-scale files over long distances, combine transfer acceleration with multipart upload and resumable download. Transfer acceleration optimizes the network path quality, while multipart operations improve concurrency and fault tolerance. Together, they significantly reduce the risk of timeouts and boost overall transfer efficiency.
Cost optimization: Implement a smart endpoint selection strategy
Implement an endpoint strategy tailored to different user groups and access scenarios. For users in the same region or with good network conditions, use the Public Endpoint to save on acceleration costs. For cross-region users or those with poor network quality, use the acceleration endpoint to improve their experience. We recommend developing an endpoint selection strategy based on your user distribution, business-criticality, and cost budget.
Fault tolerance strategies
Endpoint fallback mechanism
Your application should include an endpoint fallback mechanism that automatically switches to the public endpoint if the acceleration endpoint becomes unavailable. This ensures business continuity. Transfer acceleration and the public endpoint are independent of each other. A failure in one does not affect the other, which provides redundancy for your application.
Handling list operations
The acceleration endpoint supports only third-level domain access that includes the bucket name. Therefore, it cannot be used to list buckets. You must use the public endpoint for management operations, such as listing buckets, and use the acceleration endpoint for data operations, such as uploads and downloads. This approach separates management traffic from data traffic.
Quotas and limitations
Protocol support: The acceleration endpoint supports API access only over HTTP and HTTPS. Non-HTTP/HTTPS protocols, such as RTMP, are not supported.
Propagation time: Changes to enable or disable transfer acceleration take up to 30 minutes to propagate across the entire network.
Secure transmission: To ensure data security, the backend may use HTTPS for internal data transmission. As a result, if a client requests a file over HTTP, the access log might still record the request as HTTPS.
Billing
When you access OSS through transfer acceleration, you incur additional charges for accelerated upload and download traffic. For details, see Transfer acceleration fees.