Enable edge computing

1. Log on to the DCDN console.

2. In the navigation pane on the left, click EdgeRoutine.

3. If you are using EdgeRoutine for the first time, you must first create a subdomain.

   1. On the EdgeRoutine page, click Create Subdomain.

      

   2. In the Create Subdomain dialog box, enter a subdomain name.

      Note

      • A subdomain acts as a repository for all your routines. The subdomain cannot be changed once it is created.

      • The subdomain is a unique identifier for each user and forms part of the routine ID.

      • The name must contain only lowercase letters, digits, and hyphens (-), and must be at least two characters long, for example, subdomain-name.

   3. Click OK.

4. On the EdgeRoutine page, click Create Routine.

   

   Parameter	Description
   Routine Name	Enter a name for the routine. Note The name can contain lowercase letters, digits, and hyphens (-). The name cannot be less than 2 characters in length. Example: routine-name. The routine name cannot be modified after it is created.
   Description	(Optional) A description of the routine.
   Specification	The maximum CPU time for a single routine execution, excluding I/O wait time for network responses. The maximum runtime is 120 seconds, and the available memory is 128 MB. Fees vary based on the selected specification. The 50 ms specification is selected by default. For more information, see Billing of EdgeRoutine. CPU Time Slice for Individual Requests: 5 ms CPU Time Slice for Individual Requests: 50 ms (Default) CPU Time Slice for Individual Requests: 100 ms

5. After creating the routine, click Details in the Actions column to open its details page. Each environment (production, staging, and optional canary) has an independent configuration that you can modify.

   Parameter	Description
   Routine Specifications	The maximum CPU time for a single routine execution, excluding I/O wait time for network responses. The maximum runtime is 120 seconds, and the available memory is 128 MB. The 50 ms specification is selected by default. CPU Time Slice for Individual Requests: 5 ms CPU Time Slice for Individual Requests: 50 ms (Default) CPU Time Slice for Individual Requests: 100 ms
   Domain Name Whitelist	Specifies the domains that can be associated with this routine. Wildcard domains are supported. By default, the domain name whitelist is empty, allowing any domain to be associated with the routine. Note For example, if you add example.com to the whitelist, only requests from example.com can trigger this routine. Requests from other domains are rejected by the routine.

A routine requires a domain to serve as an entry point for client requests. You can use a domain accelerated by Alibaba Cloud CDN or DCDN. After you create and configure the routine, you must associate your or DCDN domain with it. Client requests to this domain will then trigger the routine. The procedure varies depending on the console where your domain is hosted.

1. Log on to the DCDN console.

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

3. On the Domain Names page, find the target domain name and click Configure.

4. In the navigation pane on the left for the domain, click EdgeRoutine.

5. On the EdgeRoutine page, enable the feature and configure the Routine ID.

   

   Parameter	Description
   Routine ID	The unique identifier for each routine. The format is routine-name.subdomain. Note In the navigation pane on the left of the DCDN console, click EdgeRoutine. You can find the ID of the corresponding routine on the Function page.
   Trigger Mode	Requests to the or DCDN domain trigger the routine. Two modes are available: Redirect: Requests to the or DCDN domain are fully handled by the routine. You can write your own code to directly respond to the client, read from the cache by using the Cache API, or fetch content from the origin. Bypass: Requests to the or DCDN domain only trigger the routine execution, and then proceed with the regular or DCDN configuration to redirect to origin. This mode is suitable for scenarios such as authentication or logging.
   Redirect to Origin if Error Occurs	Yes: If a routine execution fails, the point of presence (POP) forwards the client request to the origin server of the or DCDN domain. This allows you to implement fallback and disaster recovery mechanisms on your origin server. No: If a routine execution fails, the POP returns a 5xx status code directly to the client. Note The first time you use a routine, we recommend that you set the Redirect to Origin if Error Occurs parameter to No. You can use the HTTP 5xx status code that is returned to troubleshoot issues. If an exception occurs, you are charged for the number of back-to-origin requests. The percentage of abnormal back-to-origin requests is very low and can be ignored.

1. Log on to the DCDN console.

2. In the navigation pane on the left, click EdgeRoutine.

3. Select the routine that you created and click Details.

4. On the Details page, select the Code tab to develop your EdgeRoutine in JavaScript. The editor includes a default "Hello World" example.

5. After writing the code, click Release to Staging Environment. You can then use any of the provided staging environment IP addresses to map in your local hosts file for testing and debugging the routine.

   Note

   To test, modify the hosts file on your local machine to map the domain to one of the provided staging IP addresses. For example: 10.10.10.10 example.com. Replace the IP address with one of the provided IPs and the domain name with the or DCDN domain associated with the routine.