Auto Scaling:Apply an automatic snapshot policy to ECS instances

Step 1: Grant permissions to the OOS RAM role

You must have the required permissions to execute OOS templates. Executing the O&M operations defined in ACS-ESS-LifeCycleApplyAutoSnapshotPolicy involves resources from Elastic Compute Service (ECS) and Auto Scaling.

1. Log on to the Resource Access Management (RAM) console.

2. Create a permission policy.

   1. In the navigation pane on the left, click Permission Management > Access Policies.

   2. Click Create Access Policy.

   3. On the Create Policy page, click the JSON tab, enter the following policy content, and then click OK.

      {
          "Version": "1",
          "Statement": [
              {
                  "Action": [
                      "ecs:DescribeDisks",
                      "ecs:ApplyAutoSnapshotPolicy",
                      "ecs:DescribeInstances"
                  ],
                  "Resource": "*",
                  "Effect": "Allow"
              },
              {
                  "Action": [
                      "ess:CompleteLifecycleAction"
                  ],
                  "Resource": "*",
                  "Effect": "Allow"
              }
          ]
      }

   4. In the Create Policy dialog box, enter a name for the policy.

      The policy name is ESSHookPolicyForApplyAutoSnapshotPolicy.

      Note

      If you need to modify the policy content, click Cancel to continue editing the permission policy.

   5. Click OK.

3. Attach the permission policy to the OOSServiceRole RAM role.

   1. In the navigation pane on the left, click Identity Management > Roles.

   2. Find OOSServiceRole and click Add Permissions in the Actions column.

      Grant the required permissions to the OOSServiceRole RAM role.

   3. On the Grant Permission page, configure the settings and click OK.

      The following table describes the parameters used in this tutorial. Use the default values for any parameters not mentioned.Basic Information

      Parameter	Description
      Grant Scope	Select Alibaba Cloud Account.
      Policies	Add the custom policy ESSHookPolicyForApplyAutoSnapshotPolicy.

Step 2: Create a lifecycle hook and trigger a scale-out

1. Log on to the Auto Scaling console.

2. In the navigation pane on the left, click Scaling Groups.

3. In the top navigation bar, select a region.

4. Find the scaling group that you want to manage and open its details page in one of the following ways:

   • In the Scaling Group Name/ID column, click the ID of the scaling group.

   • In the Actions column, click Details.

5. Create a lifecycle hook for the scale-out event.

   1. At the top of the page, click the Event and adhesive hook tab.

   2. Click Create Lifecycle Hook.

   3. Configure the lifecycle hook and click OK.

      The following table describes the parameters used in this tutorial. Use the default values for any parameters not mentioned.

      Parameter	Description
      Name	Enter ESSHookForApplyAutoSnapshotPolicy.
      Scaling Activity Type	Select Scale-Out.
      Timeout Period	Enter an appropriate timeout period, for example, 300 seconds. Note The timeout period is the maximum time allowed for the custom action to complete. If the action does not finish within this period, it fails. Set a timeout that is long enough for your action to run successfully.
      Default Execution Policy	Select Continue.
      Send Notification When Lifecycle Hook Takes Effect	Configure the template as follows: Notification Method: Select OOS Template. OOS Template Type: Select Public Templates. Public Template: Select ACS-ESS-LifeCycleApplyAutoSnapshotPolicy. The execution parameters for ACS-ESS-LifeCycleApplyAutoSnapshotPolicy are as follows: autoSnapshotPolicyId: Enter the ID of your automatic snapshot policy. OOSAssumeRole: Select OOSServiceRole. In Step 1, you granted this RAM role the required permissions to manage ECS and Auto Scaling resources. OOS assumes this role to acquire these permissions.

6. Trigger a scale-out event.

   In this tutorial, we manually execute a scaling rule to trigger the scale-out event. You can also use other methods, such as scheduled or event-triggered tasks.

   Note

   Lifecycle hooks are triggered when you execute a scaling rule, but they are not triggered when you manually add or remove existing ECS instances from a scaling group.

   1. At the top of the page, click the Scaling Rules and Event-triggered Tasks tab.

   2. On the Scaling Rules tab, click Create Scaling Rule.

   3. Configure the scaling rule and click OK.

      The following table describes the parameters used in this tutorial. Use the default values for any parameters not mentioned.

      Parameter	Description
      Rule Name	Enter Add1.
      Rule Type	Select Simple Scaling Rule.
      Operation	Set to add 1 instance.

   4. In the list of scaling rules, find the Add1 rule and click Actions in the Recurrently column.

   5. Click OK.

   After the scaling rule is executed, one ECS instance is automatically created. The lifecycle hook ESSHookForApplyAutoSnapshotPolicy in the scaling group then suspends the ECS instance and simultaneously notifies the OOS service to execute the O&M operations defined in ACS-ESS-LifeCycleApplyAutoSnapshotPolicy.

7. Verify that the automatic snapshot policy is applied to the new ECS instance.

   1. At the top of the page, click the Instance Management tab.

   2. Find the newly created ECS instance and click its ID in the ECS Instance ID/Name column.

   3. On the Instance Details page, click the Block Storage tab.

   4. Find the cloud disk, and in the Actions column, click Set Snapshot Policy.

      • The figure below shows that an automatic snapshot policy is enabled for the cloud disk. This policy corresponds to the Automatic Snapshot Policy ID set when the lifecycle hook was created, which is the expected behavior when you use the public template ACS-ESS-LifeCycleApplyAutoSnapshotPolicy.

      • If the ECS instance was created but the automatic snapshot policy was not applied, go to the OOS console to check the task execution status.

(Optional) Step 3: View the OOS execution status

1. Log on to the OOS console.

2. In the navigation pane on the left, choose Automated Tasks > Task Execution Management.

3. Find the execution based on the start time and click Details in the Actions column.

4. On the execution details page, view the execution information.

   For example, you can view the execution ID and status in the Basic Information section. You can also click a task node in the Task Execution section to view details for that step. For more information, see View the details of an execution.

   Note

   If an execution fails, the execution details page displays an error message.