All Products
Search

This Product

    CDN:Accelerate a web portal using CDN

    Document Center

    CDN:Accelerate a web portal using CDN

    Last Updated:Mar 06, 2026

    Web portals commonly display static resources such as images, text, and videos. If your website primarily contains small image files, select Image and Small File as the business type. If your website contains many video and audio resources, select VOD. This tutorial uses testcdn.top as an example to demonstrate how to use Alibaba Cloud CDN to accelerate the delivery of Image and Small File resources stored in Object Storage Service (OSS).

    Prerequisites

    Before you begin, make sure that you have:

    • An activated CDN service. See Activate CDN

    • A stable origin server -- either an Elastic Compute Service (ECS) instance or an OSS bucket. See Create an ECS instance or Create a bucket

    • A registered domain name with DNS managed through Alibaba Cloud DNS

    Performance benchmark

    A network probe performed with Application Real-Time Monitoring Service (ARMS) compared an OSS resource URL against a CDN-accelerated domain name. CDN acceleration improved delivery speed by approximately 35%.

    The results of each network probe may vary depending on network conditions.

    Step 1: Add an accelerated domain name

    1. Log on to the CDN console.

    2. In the left-side navigation pane, click Domain Names.

    3. On the Domain Names page, click Add Domain Name.

    4. Configure the domain settings: > Important: > - The first time you add an accelerated domain name, verify its ownership. See Verify the ownership of a domain name. > - If the acceleration region includes the Chinese mainland, the accelerated domain name must have an ICP filing.

      Parameter Value
      Region Global (Excluding the Chinese Mainland)
      Domain Name to Accelerate images.testcdn.top
      Business type Image and Small File
      Resource group Default

    5. Click Add Origin Server and configure the origin:

      Parameter Value
      Origin Info OSS Domain
      Domain Name Select the domain name for Internet access
      Priority Primary
      Weight 10
      Port 80

    6. Read and agree to the Compliance Warranty Regarding Cross-border Data Transfers, click Next, and then click Back to Domain Management.

    Step 2: Configure a CNAME record

    After adding the domain, point your DNS to the CDN-assigned CNAME so that traffic routes through CDN edge nodes.

    1. On the Domain Names page in the CDN console, find the domain name you added and copy its CNAME value.

    2. Log on to the Alibaba Cloud DNS console.

    3. On the Public Zone page, find the root domain testcdn.top and click Settings in the Actions column.

    4. Click Add Record and configure:

      Parameter Value
      Record Type CNAME
      Hostname images
      Query Source Default
      Record Value The CNAME copied in step 1
    DNS propagation typically takes a few minutes but can take up to 48 hours depending on your DNS provider and TTL settings. During propagation, some users may still reach the origin directly.

    Step 3: Verify the setup

    After DNS propagation completes, verify that CDN is serving your content:

    1. Open a browser and navigate to a resource on the accelerated domain, for example:

         https://images.testcdn.top/example-image.png

    2. Check the HTTP response headers. A successful CDN setup includes headers such as Via or X-Cache indicating a cache hit or miss from a CDN edge node.

    3. Alternatively, use curl to inspect the response headers: Look for CDN-specific headers in the output to confirm that the request was processed by CDN.

         curl -I https://images.testcdn.top/example-image.png

    Troubleshooting

    403 error when accessing accelerated resources

    If you receive a 403 error after completing the setup, the most likely cause is that your OSS bucket has private access permissions. CDN cannot fetch content from a private bucket without explicit authorization.

    To fix this:

    1. In the CDN console, go to the Domain Names page, find images.testcdn.top, and click Manage.

    2. Click the Origin Fetch tab.

    3. In the Alibaba Cloud OSS Private Bucket Access section, turn on the Status switch.

    4. Set Type to Bucket in the Same Account.

    5. Access the resource again and confirm that it loads normally.

    Enabling private bucket origin fetch allows CDN to authenticate requests to your OSS bucket. This keeps the bucket private while still serving content through CDN.

    Clean up resources

    If you set up this tutorial as a learning exercise, delete the resources that you no longer need:

    1. In the CDN console, go to Domain Names, find the accelerated domain name, disable it first, and then delete it.

    2. In the Alibaba Cloud DNS console, remove the CNAME record you added.

    3. If the OSS bucket was created solely for this tutorial, delete it.

    Next steps