Auto Scaling:Automatically add or remove the private IP addresses of ECS instances to or from the IP address whitelist of a PolarDB cluster

Procedure

In this example, a public OOS template named ACS-ESS-LifeCycleModifyPolarDBIPWhitelist is used to show how to automate the addition of instance IP addresses to the IP address whitelist of a PolarDB cluster during a scale-out event. Perform the following steps:

Step 1: Grant a RAM role the permissions on OOS

You must have the permissions to execute OOS templates. The ACS-ESS-LifeCycleModifyPolarDBIPWhitelist template includes ECS, Auto Scaling, and PolarDB resources that are required to perform O&M tasks.

1. Log on to the RAM console.

2. Create a policy.

   1. In the left-side navigation pane, choose Permissions > Policies.

   2. Click Create Policy.

   3. On the Create Policy page, click the JSON tab, configure parameters based on your business requirements, and then click OK.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Name	Enter ESSHookPolicyForPolarDBWhitelist.
      Policy document	Enter the following content: { "Version": "1", "Statement": [ { "Action": [ "ecs:DescribeInstances" ], "Resource": "*", "Effect": "Allow" }, { "Action": [ "polardb:DescribeDBClusterAccessWhitelist", "polardb:ModifyDBClusterAccessWhitelist" ], "Resource": "*", "Effect": "Allow" }, { "Action": [ "ess:CompleteLifecycleAction" ], "Resource": "*", "Effect": "Allow" } ] }

3. Attach the policy to the OOSServiceRole RAM role.

   1. In the left-side navigation pane, choose Identities > Roles.

   2. Find OOSServiceRole and click Grant Permission in the Actions column.

      Add the required permissions for the OOSServiceRole RAM role that is assumed by OOS to complete the authorization.

   3. In the Grant Permission panel, configure Resource Scope and Policy. After you complete the configuration, click Grant permissions.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Resource Scope	Set the value to Account.
      Policy	Select the following custom policy: ESSHookPolicyForPolarDBWhitelist.

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

1. Log on to the Auto Scaling console.

2. In the left-side navigation pane, click Scaling Groups.

3. In the top navigation bar, select the region where Auto Scaling is activated.

4. Find a scaling group and use one of the following methods to go to the scaling group details page:

   • Click the ID of the scaling group in the Scaling Group Name/ID column.

   • Click Details in the Actions column.

5. Create a lifecycle hook.

   1. In the upper part of the scaling group details page, click the Lifecycle Hook tab.

   2. Click Create Lifecycle Hook.

   3. Configure parameters based on your business requirements and click OK.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Name	Enter ESSHookForAddPolarDBWhitelist.
      Scaling Activity	Select Scale-out Event.
      Timeout Period	Configure Timeout Period based on your business requirements. In this example, set the value to 300. Unit: seconds. Note The timeout period is the period of time during which you can perform custom operations on instances. If the timeout period is shorter than the period of time that is required to perform custom operations, the operations may fail. We recommend that you estimate the period of time that is required to perform custom operations on instances and configure Timeout Period based on your estimations.
      Default Execution Policy	Select Continue.
      Send Notification When Lifecycle Hook Takes Effect	Configure the following parameters for the template: Select OOS Template. Select Public Templates. Select ACS-ESS-LifeCycleModifyPolarDBIPWhitelist. In the ACS-ESS-LifeCycleModifyPolarDBIPWhitelist public template, you must also configure the following parameters: dbClusterId: Enter the ID of the PolarDB cluster. modifyMode: Select Append. This value applies to the scale-out event during which Auto Scaling adds the private IP addresses of your ECS instances to the IP address whitelist of the PolarDB cluster. OOSAssumeRole: Select OOSServiceRole. In Step 1, OOSServiceRole is granted the permissions on the ECS, Auto Scaling, and PolarDB resources. OOS obtains the preceding permissions after it assumes the RAM role.

6. Trigger a scale-out event.

   In this example, a scale-out event is manually triggered by executing a scaling rule. You can also trigger scale-out events by using scheduled or event-triggered tasks.

   Note

   If scaling events are triggered when you manually execute scaling rules, lifecycle hooks take effect. However, lifecycle hooks do not take effect when you manually add or remove ECS instances to or from a scaling group.

   1. In the upper part of the page that appears, click the Scaling Rules and Event-triggered Tasks tab.

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

   3. In the Create Scaling Rule dialog box, configure parameters based on your business requirements and click OK.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Rule Name	Enter Add1.
      Rule Type	Select Simple Scaling Rule.
      Operation	Set the value to Add 1 Instances.

   4. On the Scaling Rules page, find the Add1 scaling rule and click Execute in the Actions column.

   5. In the Execute Scaling Rule message, click OK.

   After the scaling rule is executed, Auto Scaling adds one ECS instance to the scaling group. However, the ECS instance enters the Pending Add state because of the ESSHookForAddPolarDBWhitelist lifecycle hook that is in effect. During the timeout period of the lifecycle hook, Auto Scaling notifies OOS to execute the O&M tasks that are defined in the ACS-ESS-LifeCycleModifyPolarDBIPWhitelist public template.

Step 3: Check the IP address whitelist of the PolarDB cluster

1. Log on to the PolarDB console.

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

3. Search for the desired PolarDB cluster and click the ID in the Cluster ID/Name column.

4. In the left-side navigation pane, choose Settings and Management > Cluster Whitelists.

   • If the private IP address of the ECS instance is added to the IP address whitelist of the PolarDB cluster, the ACS-ESS-LifeCycleModifyPolarDBIPWhitelist public template takes effect.

   • If the ECS instance is created but its private IP address is not added to the IP address whitelist of the PolarDB cluster, go to the OOS console to view the execution of the O&M tasks. For more information, see Step 4: (Optional) View the OOS execution.

Step 4: (Optional) View the OOS execution

1. Log on to the OOS console.

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

3. Find the execution task by time and click Details in the Actions column.

4. On the execution details page that appears, view the related information.

   For example, in the Basic Information section, you can view the execution ID and status. In the Execution Steps and Results section, you can click a task node to view the execution details. For more information, see View the details of an execution.

   Note

   If the execution fails, an error message is displayed on the execution details page.

Common errors and troubleshooting