Alibaba Cloud CDN quick start

Add domain name and origin server

1. Configure domain name

   To enable acceleration for your domain name, add it to Alibaba Cloud CDN as an Domain Name to Accelerate. This allows Alibaba Cloud CDN to identify and accelerate requests for the domain.

   Add a domain name

   1. Log on to the CDN console.

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

   3. Click Add Domain Name. Configure Region, Domain Name to Accelerate, and Business Type. You can leave the other parameters at their default values.

   Note

   • An Domain Name to Accelerate is the domain name you add to Alibaba Cloud CDN for acceleration. It is also the domain name that end users access. In this example, enter www.example.com.

   • www.example.com and example.com are two different domain names. If you want to accelerate both domain names, you must add www.example.com and example.com separately in the CDN console and configure a CNAME record for each. You cannot point the CNAME record of an apex domain directly to the CDN CNAME address of a subdomain.

   • For Region, select an acceleration region that suits your business needs. This example uses Chinese Mainland Only. If the acceleration region includes the Chinese mainland, the domain name requires an ICP filing to be accessible.

   • For Business Type, select a type that fits your use case. This example uses Image and Small File.

   • When Region is set to Global (Excluding the Chinese Mainland), you can enable the Global Resource Plan. When enabled, your domain name leverages more POP resources but has limited feature support. For more information, see Features supported after the Global Resource Plan is enabled. Evaluate this feature carefully before enabling it.

2. Q: Considerations for a unified accelerated domain name

   When you configure a unified accelerated domain name, consider the following:

   1. Business type selection: Select 'Image and Small File' to optimize for static resource acceleration.

   2. Shared cache: If multiple accelerated domain names serve identical content from the origin server, enable shared cache to improve the cache hit ratio.

   3. HTTPS support: To support HTTPS access, you must configure a separate SSL certificate for each accelerated domain name.

   4. Origin host header settings: Set the origin host header to the origin's actual domain name to prevent host header mismatches.

   5. Domain name addition rules: Add each domain name as a separate accelerated domain name in Alibaba Cloud CDN. For example, www.example.com and example.com are two different domain names and must be added as accelerated domain names and configured with CNAME records separately in the CDN console.

3. Verify domain ownership

   Alibaba Cloud CDN requires domain ownership verification to confirm that you own the domain name. You can skip this step if you have already verified the domain or if no verification prompt appears.

   Verify domain ownership

   Important

   Do not close the verification tab until the verification is complete.

   DNS record verification (Recommended)

   1. On the verification tab of the Add Domain Name page, click Method 1: DNS Settings to obtain the host record and record value.

      Go to your DNS provider and add a TXT record. Set Host to verification and Value to the verification value displayed on the page. After you configure the record, select Configured and click Verify to complete the domain ownership verification.

   2. Add a TXT record at your DNS provider. The following example shows how to add a TXT record in Alibaba Cloud DNS. The process is similar for other DNS providers, such as Tencent Cloud or Xinnet.

      Configure a TXT record

      2. Log on to the Alibaba Cloud DNS console.

      3. On the Public Zone page, find the root domain name example.com of your accelerated domain name and click DNS Records in the Actions column.

      4. Click Add Record. Set Type to TXT. Enter the Host and Value provided by Alibaba Cloud CDN in Step 1. You can leave the other parameters at their default values.

      2. Click OK to add the record.

      Note

      For more information about the definitions of and differences between root domains and subdomains, see Domain name basics.

   3. Wait for the TXT record to take effect. Then, return to the verification tab in the CDN console and click Verify to complete the verification.

      If the "Verification failed" message appears, check whether your TXT record is correctly configured and try again after the DNS record takes effect.

      Check whether the TXT record has taken effect

      Use the following method to check if the TXT record for the accelerated domain name www.example.com is correct and has taken effect:

      Windows

      Open Command Prompt and run the nslookup -type=TXT verification.example.com command. Check the TXT result to confirm that the DNS record is correct and has taken effect.

      The following code provides a sample command output.

      C:\Users\xxx> nslookup -type=TXT verification.example.com
      Server:  UnKnown
      Address:  fd00:1::1
      DNS request timed out.
          timeout was 2 seconds.
      Non-authoritative answer:
      verification.example.com    text =
              "verify_0xxx...xxxff22"

      macOS/Linux

      In the terminal, run the nslookup -type=TXT verification.example.com command. Check the TXT result to confirm that the DNS record is correct and has taken effect.

      [root@xxx ~]# nslookup -type=TXT verification.example.com
      Server:		 xxx.xxx.xxx.xxx
      Address:	 xxx.xxx.xxx.xxx#53
      Non-authoritative answer:
      verification.example.com	text = "verify_xxx981c5ebff22"
      Authoritative answers can be found from:

      Note

      • In the nslookup command, the record type is TXT. The domain name to verify is your original domain name with the hostname replaced by verification. For example, if your accelerated domain name is www.example.com, the domain name you need to verify is verification.example.com.

      • A new TXT record typically starts propagating immediately. Modifications to an existing record take effect after its time to live (TTL) expires.

      • If the nslookup command is not installed on your Linux system, run yum install bind-utils on CentOS or apt-get install dnsutils on Ubuntu to install it.

   File verification

   1. On the verification page, click Method 2: Verification File.

      Follow the on-screen instructions to complete the file verification: download the verification.html file, upload it to the root directory of your origin server (ensure it is accessible at http://example.com/verification.html), and then click Verify to complete the domain ownership verification.

   2. Click verification.html to download the verification file.

   3. Upload the verification file to the root directory of your origin server, such as your ECS, OSS, CVM, COS, or EC2 instance. For example, if your accelerated domain name is www.example.com, upload the file to the root directory of example.com.

   4. After you confirm that the file is accessible at http://example.com/verification.html, click Verify.

      Alibaba Cloud CDN accesses the http://example.com/verification.html file on your server for verification.

      • If the content of the file matches the expected verification value, the verification is successful.

      • If the verification fails, make sure that the file URL is accessible and that you uploaded the correct file.

4. Configure origin server information

   An origin server is a web server that hosts your application content. When a cache miss occurs, a CDN node retrieves the requested resource from the origin server.

   Configure origin server information

   1. After you configure the business information for the domain name, click Add Origin Server in the Origin Servers section.

   2. In the dialog box that appears, select the type of origin server and enter its address.

   3. Enter the Port based on your origin server's settings. By default, port 80 for HTTP is used.

      In the Add Origin Server dialog box, select an Origin Info type (OSS Domain, IP, Site Domain, or Function Compute Domain). Set the Priority (0-127, lower values are higher) and Weight (1-100). For example, you can set a primary origin's priority to 20 and a backup's to 30. For Port, you can use the default HTTPS port 443 or a custom port from 1 to 65535. After you complete the configuration, click OK.

   Note

   • This example uses the IP address 10.10.10.1 to configure the origin server.

     • To accelerate resources in OSS, select OSS Domain for Origin Info.

     • To accelerate resources deployed on an ECS instance, select IP for Origin Info and enter the public IP address of the ECS instance.

     • If your resources are on a server that cannot be accessed by IP address, select Site Domain for Origin Info and enter the domain name of the origin server. The origin domain name cannot be the same as the accelerated domain name. Otherwise, a DNS resolution loop occurs.

     • To accelerate resources in Function Compute, select Function Compute Domain for Origin Info, and then select the region and domain name based on your Function Compute resources.

   • If your origin server hosts multiple websites, you must also configure an origin host header.

   • For more information about origin server parameters, see Configure an origin server.

   • For best practices for using Alibaba Cloud CDN with OSS, see Accelerate access to OSS resources by using Alibaba Cloud CDN.

5. Verify accelerated domain name

   After you add the accelerated domain name, we recommend that you test it on a local machine first. This allows you to switch DNS records without impacting production traffic. After you verify that the accelerated domain name is working correctly, point its DNS record to the CNAME address.

   Note

   Simulated access incurs standard CDN charges. For more information, see Billing components.

   Verify the accelerated domain name

   1. Obtain the CNAME address of the accelerated domain name.

      1. Log on to the CDN console.

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

      3. On the Domain Names page, copy the CNAME address that corresponds to the accelerated domain name.

         Note

         Copy the CNAME address only when its status is Normal.

         In the domain name list on the Domain Names page, the corresponding CNAME address (for example, xxx.alikunlun.com) is displayed in the CNAME column.

   2. Obtain the IP address that corresponds to the CNAME. In a command-line interface such as CMD, PowerShell, or Terminal, run the nslookup command to query the CNAME address for its corresponding IP addresses. Example:

      nslookup www.example.com.w.kunlunle.com 

      nslookup www.example.com.w.kunlunle.com
      Server:         100.100.XX.XX
      Address:        100.100.XX.XX#53
      Non-authoritative answer:
      www.example.com.w.kunlunle.com	canonical name = xxx.p.kunlunle.com.
      Name:   xxx.p.kunlunle.com
      Address: 117.XX.XX.214
      Name:   www.example.com.w.kunlunle.com
      Address: 2408:XXXX:1:3::3fa

   3. Modify the hosts file on your local computer.

      Add an entry that maps the IP address obtained in the previous step to the accelerated domain name in the local hosts file. The IP address must come before the accelerated domain name. Do not reverse the order. The following example uses the IP address 117.XX.XX.214, obtained from the preceding nslookup command.

      Windows

      1. Go to the C:\Windows\System32\drivers\etc directory and open the hosts file by using a text editor, such as Notepad, with administrator permissions.

      2. Edit the hosts file. The file content may be similar to the following:

         # localhost name resolution is handled within DNS itself.
         # 127.0.0.1       localhost
         # ::1             localhost

         Add the obtained IP address and the accelerated domain name to the end of the file. Example:

         117.XX.XX.214   www.example.com

      3. Save the changes. After you finish editing, select File > Save or press Ctrl+S.

      4. (Optional) Flush the DNS cache to ensure that the DNS changes take effect immediately.

         Open Command Prompt with administrator permissions, enter the following command, and then press Enter:

         ipconfig /flushdns

      macOS

      1. Open Terminal and run the following command to open the hosts file with administrator permissions.

         sudo vim /etc/hosts

      2. Edit the hosts file. The file content may be similar to the following:

         ##
         # Host Database
         #
         # localhost is used to configure the loopback interface
         # when the system is booting.  Do not change this entry.
         ##
         127.0.0.1   localhost
         255.255.255.255 broadcasthost
         ::1         localhost

         Add the obtained IP address and the accelerated domain name to the end of the file. Example:

         117.XX.XX.214   www.example.com

      3. Save the changes and exit.

         Press the Esc key to exit insert mode, then type :wq and press Enter to save the file and exit Vim.

      4. (Optional) Flush the DNS cache to ensure that the DNS changes take effect immediately.

         In Terminal, enter the following command and press Enter:

         sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

   4. Test whether the accelerated domain name is accessible.

      After you modify the hosts file, open a browser and access the accelerated domain name to test connectivity. You can view the test results by using the browser's developer tools.

      • If the IP address in the Remote Address field matches the one you added to your hosts file, the configuration is successful. You can then proceed to configure the CNAME record with your DNS provider. Open the Network panel in your browser's developer tools, select the request entry that corresponds to the accelerated domain name, and go to the Headers panel. In the General section, confirm that the Status Code is 200 OK and check the IP address displayed in the Remote Address field.

      • If the IP address in the Remote Address field does not match the IP address you added to the hosts file, the configuration is incorrect. Check whether the IP address in the hosts file is the correct IP address of the CNAME.

      After you can access the accelerated domain name, you can perform other verification tests on your local machine if needed.

Recommended Configurations

After you configure the domain name and origin server, click Next to go to the Recommended Configurations page.

The Recommended Configurations section provides four configurations, Improve cache hit ratio, Improve access performance, Cost control, and Improve access security, to quickly improve the cache hit ratio, access performance, and security of your CDN.

You can configure features based on your business needs or skip this step. You can access this page again later by clicking Quick Configuration in the Action column on the Domain Names page.

Q: Hotlink protection and bandwidth limiting for CDN-to-OSS

When your CDN fetches images from OSS, use the following quick configuration settings to enable hotlink protection and control bandwidth costs:

1. Hotlink protection: In the 'Improve Access Security' section of quick configuration, set up Referer-based hotlink protection with a whitelist of your allowed domain names. Alternatively, use an IP blacklist to block malicious IPs. This prevents unauthorized use of your resources.

2. Bandwidth limiting: In the 'Prevent Excessive Costs' section of quick configuration, set a bandwidth threshold. If this threshold is exceeded, a capping rule is triggered that takes the accelerated domain name offline to control traffic and costs. The domain automatically comes back online after the unblocking period ends.

3. Configure CNAME

Configure a CNAME record to point your domain name to the nearest CDN point of presence (POP) to route user requests through Alibaba Cloud CDN for acceleration.

A CNAME record is a type of DNS record that maps one domain name to another. For more information, see Introduction to CNAME records.

Resource prefetch

After you add a domain name to CDN, you can prefetch popular static resources to CDN POPs. This provides faster access for first-time visitors by serving content directly from the cache.

1. Log on to the CDN console.

2. In the navigation pane on the left, click Purge and Prefetch.

3. On the Purge/Prefetch tab, set the operation type to Prefetch.

4. In the input box, enter the full URL of each file to prefetch. Enter one URL per line. Prefetching directories is not supported. For example: https://www.example.com/install/package.zip.

5. Click Submit.

6. On the operation records tab, view the details and progress of your purge or prefetch tasks. A task is complete when its progress reaches 100%.

Step 5: Verify Alibaba Cloud CDN caching

After completing these steps, you have configured Alibaba Cloud CDN to accelerate your website.