Configuring Auto Cache Refresh for the CDN Acceleration Domain Name of a Bucket

To use the auto CDN cache refresh, you must create an IAM agency that grants OBS permission to view acceleration domain names and refresh the cache. If you already have such an agency, skip this step.

1. Log in to the management console and go to the Identity and Access Management page.
2. Choose Agencies from the navigation pane, and click Create Agency in the upper right corner.
   Figure 1 Creating an agency
   

3. Configure the parameters for CDN cache refresh as described in the following table. Retain the default settings for other parameters.

   Table 1 Parameters

   Parameter	Description
   Agency Name	The name of the agency to be created The agency name cannot be left blank.
   Agency Type	Selecting Cloud service grants permissions to an account or cloud service to operate resources within the account. In this example, you need to create an agency for auto CDN cache refresh, so select Cloud service here.
   Cloud Service	Select the cloud service you want to grant permissions to operate resources in your account. This parameter is mandatory when you set Agency Type to Cloud service. In this example, you need to create an agency for auto CDN cache refresh, so select Object Storage Service (OBS) here.

4. Click OK. In the Agency Created dialog box that is displayed, click Cancel. If the newly created agency appears in the agency list, the agency is created successfully.
5. Create a custom policy that grants CDN permissions to the agency.
   1. In the navigation pane of the IAM console, choose Permissions > Policies/Roles.
   2. On the Policies/Roles page, click Create Custom Policy in the upper right corner.
   3. On the Create Custom Policy page, configure the parameters as described below. Keep the default settings for other parameters.
      Figure 2 Configuring a custom policy
      
      • Policy Name: Enter a name that is easy to remember.
      • Select service: Select Content Delivery Network (CDN).
      • Actions: Under ReadOnly, select cdn:configuration:queryDomains, and under ReadWrite, select cdn:configuration:refreshCache.
      • Resources: Select All, which is the only option.
   4. Click OK. If the created custom policy appears in the list, it was created successfully.

6. Apply the created custom policy that grants CDN permissions to the agency.
   1. In the navigation pane of the IAM console, choose Agencies.
   2. Locate the agency created in 2 and click Authorize in the Operation column.
   3. On the Select Policy/Role page, select the custom policy created in 5 and click Next.
   4. On the Select Scope page, select All resources and click OK.
      

      To make sure the agency can work well, All resources is the only recommended option. In this policy, the All resources option means that OBS can use all resources under the account, including those in enterprise projects, region-specific projects, and global services, based on the assigned permissions.

   5. In the Information dialog box that is displayed, click OK.
   6. On the Finish page, click Finish.

After the acceleration domain name is configured and the CNAME record set has taken effect, you need to configure an auto cache refresh policy for CDN. This ensures that the cached data on CDN PoPs stays consistent with the data stored on the origin server (OBS).

1. Log in to OBS Console.
2. Click the name of the target bucket to go to the Objects page.
3. In the navigation pane, choose Basic Configurations > Domain Name Mgmt.
4. In the domain name list, locate the card of the domain name for which you want to configure auto cache refresh and click Configure on the right of Auto Cache Refresh. The Auto Cache Refresh dialog box is displayed.
5. In the displayed dialog box, configure related parameters.

   Table 2 Event trigger parameters

   Parameter	Description
   Auto Cache Refresh	Choose whether to enable auto cache refresh. If the switch is toggled on, auto cache refresh is enabled.
   Events	Events for which the auto cache refresh takes effect. OBS supports the following events: ObjectCreated: PUT, POST, COPY, and CompleteMultipartUpload ObjectCreated:Put: uploading objects using PUT ObjectCreated:Post: uploading objects using POST ObjectCreated:Copy: copying objects using COPY ObjectCreated:CompleteMultipartUpload: assembling parts in a multipart upload ObjectRemoved: deleting objects ObjectRemoved:Delete: deleting objects
   Prefix	You can specify a prefix to define a set of objects the auto cache refresh policy applies to. When any object with the specified prefix is updated, the policy is triggered, which ensures that the cached content on CDN PoPs stays consistent with the objects in the OBS bucket. If you configure a prefix, the auto refresh policy applies to the objects with the specified prefix. An example is given as follows: If the prefix is set to abc, the auto cache refresh policy applies to all objects whose names start with abc in the bucket, such as abcdef.txt, abc/def.txt, and abc/def/test.txt. If neither a prefix nor a suffix is configured, the auto cache refresh policy applies to all objects in the bucket. Multiple prefixes are not supported.
   Suffix	You can specify a suffix to define a set of objects the auto cache refresh policy applies to. When any object with the specified suffix is updated, the policy is triggered, which ensures that the cached content on CDN PoPs stays consistent with the objects in the OBS bucket. If you configure a suffix, the auto refresh policy applies to the objects with the specified suffix. An example is given as follows: If the suffix is set to abc.txt, the auto cache refresh policy applies to all objects whose names end with abc.txt in the bucket, such as 123abc.txt, test/123abc.txt, and test/test02/abc.txt. If neither a prefix nor a suffix is configured, the auto cache refresh policy applies to all objects in the bucket. Multiple suffixes are not supported.
   IAM Agency	To use the auto CDN cache refresh, you must create an IAM agency that grants OBS permission to view acceleration domain names and refresh the cache. For details, see Step 1: Create an Agency for Auto CDN Cache Refresh.

If auto cache refresh is enabled, you need to wait for a maximum of 5 minutes for the configuration to take effect after the CNAME status changes to Enabled.