Dynamic Content Delivery Network:Enable edge computing

1. Log on to the DCDN console.

2. In the left-side navigation pane, click EdgeRoutine.

3. The first time you use EdgeRoutine, create a subdomain.

   1. On the EdgeRoutine page, click Create Subdomain.

      

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

      Note

      • A subdomain is a repository in which all routines that you create reside. After you create a subdomain, you cannot modify the name of the subdomain.

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

      • You cannot modify a subdomain after you create the subdomain. The name can contain lowercase letters, digits, and hyphens (-). The name must be at least 2 characters in length. Example: subdomain-name.

   3. Click OK.

4. On the EdgeRoutine page, click Create Routine. The following table describes the parameters.

   

   Parameter	Description
   Routine Name	Enter a routine name. 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. Enter a description for the routine.
   Specification	Select the maximum CPU time slice for a single execution of a routine. The I/O time to wait for network responses is not included. The fees vary based on routine specifications. For more information, see Billing rule. 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 you create the routine, click Details in the Actions column to configure the routine in different environments. Routine settings are independent across environments. You can modify the routine settings in the production environment, staging environment, and canary release environment. For more information, see Canary release environment (optional). The following table describes the parameters.

   Parameter	Description
   Routine Specifications	The maximum CPU time slice for a single execution of a routine. The I/O time to wait for network responses is not included. Maximum Real Time: 120s. Memory: 128 MB. 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	Domain names that can be associated with the routine. Wildcard domain names are supported. By default, the domain name whitelist is empty. This indicates that any domain name can be associated with the routine. Note For example, if you set the Domain Name Whitelist parameter to example.com, only requests from example.com can trigger the routine. Requests from other domain names do not trigger the routine.

A routine requires a domain name to provide services to the client. The domain name can be a CDN-accelerated domain name or a DCDN-accelerated domain name. After you create and configure a routine, you need to associate DCDN-accelerated domain names with the routine. The routine is triggered by requests from the domain name that is associated with the routine. Log on to the console of the service to which your domain name is added.

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 domain name whose acceleration region you want to change and click Configure.

4. In the left-side navigation pane, click EdgeRoutine.

5. On the EdgeRoutine page, configure the Routine ID parameter. The following table describes the parameters.

   

   Parameter	Description
   Routine ID	The routine ID is a unique identifier for each routine. Format: routine name.subdomain. Note In the left-side navigation pane of the DCDN console, click EdgeRoutine. You can view the ID of the routine on the Function page.
   Trigger Mode	Select a mode in which requests that want to access the DCDN-accelerated domain name trigger the routine. The following modes are supported: Redirect: Requests that want to access the DCDN-accelerated domain name are processed by the routine. You can write the code in the routine to process requests. The routine can return the requested content to clients, read the cache by calling the Cache API, or redirect requests to the origin server by sending fetch requests. Bypass: Requests that want to access the DCDN-accelerated domain name trigger the routine. The routine processes the requests, settings that are configured in the DCDN console are executed, and then requests are redirected to the origin server. This trigger mode is suitable for scenarios such as authentication or log tracking.
   Redirect to Origin if Error Occurs	Yes: When the routine throws an exception, the point of presence (POP) forwards the request to the origin server of the DCDN-accelerated domain name by using the URL that is requested by the client. The origin server processes the request. This ensures business continuity and disaster recovery. No: When the routine throws an exception, an HTTP 5xx status code is returned 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 left-side navigation pane, click EdgeRoutine.

3. Find the routine that you created and click Details in the Actions column.

4. On the Details page, click the Code tab to develop a routine by using JavaScript. In the sample code, the HelloWorld script is used.

5. After you write the code, click Publish to Test Environment. You can associate an IP address of the staging environment that is provided on the page with the machine that you use to debug the routine.

   Note

   You can add the IP address of the staging environment and the domain name that is associated with the routine to the hosts file of your on-premises machine. For example, add 10.10.10.10 and example.com to the hosts file of your on-premises machine. Replace the IP address with the IP address that is provided in the preceding figure, and replace the domain name with the DCDN-accelerated domain name that is associated with the routine.