Auto Scaling:Manually configure instances for a scaling group

Manually add instances to a scaling group

The procedure for adding an instance varies by type. Follow these steps:

1. Log on to the Auto Scaling console.

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

3. Find the scaling group you want to manage and open its details page by doing one of the following:

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

   • In the Actions column, click View Details.

4. In the upper part of the details page, click the Instance Management tab.

5. Follow the appropriate steps for your instance type.

   ECS and ECI instances

   Considerations

   Before you manually add an ECS instance or ECI instance, note the following:

   • You can add ECI instances only to ECI-type scaling groups, and ECS instances only to ECS-type scaling groups.

   • A manually added instance's configuration, such as its instance type and image, does not need to match the active scaling configuration.

   • Adding an ECS instance or ECI instance to a scaling group triggers a scaling activity that runs immediately without a cooldown period. For more information, see cooldown period.

   • Manually adding an instance affects the group's instance count as follows:

     • The minimum and maximum instance counts of the scaling group do not change.

     • expected instance count (after adding) = expected instance count (before adding) + Number of manually added instances

     • Total number of instances in the group (before adding) + Number of manually added instances ≤ maximum instance count.

       Important

       The operation fails if adding the instances would cause the total instance count or the new expected instance count to exceed the maximum instance count.

       For example:

       Before adding instances	After adding instances
       Current scaling group configuration: minimum instance count: 1 maximum instance count: 6 expected instance count: 3 current number of instances: 2	You can add a maximum of 3 instances. The configuration changes as follows: minimum instance count: 1 maximum instance count: 6 expected instance count: 6 current number of instances: 5

   Procedure

   The following example shows how to manually add an ECS instance. Use the same steps to manually add an ECI instance.

   1. Find the Manually Added list.

   2. Click Add Existing Instance.

   3. In the Add Existing Instance dialog box, select the ECS instances to add, and then click Add.

      If you select You can hand over the management of the lifecycle for the ECS instance to the scaling group., the ECS instance is released when it is removed from the scaling group during a scale-in activity. You can manually add subscription instances to a scaling group, but you cannot enable the scaling group to manage the lifecycle of subscription instances.

      Warning

      Make sure that you have sufficient balance within your Alibaba Cloud account. Overdue payments in your Alibaba Cloud account will result in the suspension or release of pay-as-you-go and preemptible instances. For information about how the status of an ECS instance changes in the event of overdue payments, see Overdue payments.

      

      After the instances are added, you can view their information, such as progress and health status, in the Instances > Manually Added list.

   Managed instances

   Use Cloud Assistant to register non-Alibaba Cloud servers as Alibaba Cloud managed instances. After registration is complete, the servers can use various Alibaba Cloud services, such as Cloud Assistant, Auto Scaling, CloudOps Orchestration Service, and Alibaba Cloud DevOps. For more information, see Alibaba Cloud managed instances.

   1. Find the Managed Instance list.

   2. Click Add Instance.

   3. In the Add Managed Instance dialog box, select the instances that you want to manage, and then click Add.

      After the instances are added, you can view their information, such as ID, name, status, and join time, in the Managed Instance list.

View instances in a scaling group

After you manually add instances, you can view the added ECS instances, ECI instances, or managed instances in the scaling group.

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 a region.

4. Find the scaling group that you want to manage, and in the Actions column, click View Details.

5. In the upper part of the details page, click the Instance Management tab.

6. View the ECS instances, ECI instances, or managed instances in the scaling group.

   Instances are organized into lists based on their creation method:

   Automatically created instances

   The Auto Created list contains instances that the scaling group created automatically. If an automatically created ECS instance or ECI instance is identified as unhealthy, it is automatically removed from the scaling group and released.

   You can manually change the state of created ECS instances or ECI instances. For example, you can move an instance to the standby state, move it to the protection state, or remove it from the protection state. You can also manually remove an instance from the scaling group or release the instance. For more information, see Manually change the status of an instance and Manually remove or delete instances.

   Manually added instances

   The Manually Added list contains instances that you manually added to the scaling group. If a manually added ECS instance or ECI instance is not in the Running state, it is identified as unhealthy and automatically removed from the scaling group. Whether the instance is released upon removal depends on its lifecycle management setting:

   • If the instance lifecycle is not managed by the scaling group, the instance is only removed from the scaling group but not released.

   • If the instance lifecycle is managed by the scaling group, the instance is removed from the scaling group and released.

   You can manually change the state of created ECS instances or ECI instances. For example, you can move an instance to the standby state, move it to the protection state, or remove it from the protection state. You can also manually remove an instance from the scaling group or release the instance. For more information, see Manually change the status of an instance and Manually remove or delete instances.

   Managed instances

   The Managed Instance list contains the managed instances that have been added to an ECS-type scaling group. Managed instance IDs start with mi-. Unlike other Alibaba Cloud instances, managed instances do not support lifecycle hooks, load balancer association, or health checks.

   The scaling group does not manage the lifecycle of a managed instance after it is added. You can only manually remove the managed instance from the scaling group. When removed, the managed instance is not released.

   Note

   For information about how to manage managed instances by using Auto Scaling, see Monitor and automatically scale ECS instances and non-Alibaba Cloud instances.

Manually remove or delete instances

Considerations

You can remove or delete instances from a scaling group if it is in the Enable state and has no ongoing scaling activities. Before you proceed, note the following:

• Removing or deleting an ECS instance or ECI instance triggers a scale-in activity that runs immediately, bypassing the cooldown period. For more information, see cooldown period.

• The operation fails if removing or deleting the instances causes the total number of instances in the scaling group to fall below the minimum instance count.

• Managed instances can only be removed from a scaling group; they are not released upon removal.

• Successfully triggering a scaling activity does not guarantee that the activity will execute successfully. To view the execution result, see View scaling activity details.

Procedure

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 a region.

4. Find the scaling group that you want to manage, and in the Actions column, click View Details.

5. In the upper part of the details page, click the Instance Management tab.

6. Navigate to the list that contains the instances.

   • To select an automatically created ECS instance or ECI instance, go to the Auto Created list.

   • To select a manually added ECS instance or ECI instance, go to the Manually Added list.

   • To select a manually added managed instance, go to the Managed Instance list.

7. Manually remove or delete the instances.

   Action	Steps
   Manually remove ECS or ECI instances	For a single instance: Find the instance that you want to remove. In the Actions column, click > Remove from Scaling Group. For multiple instances: Select the instances that you want to remove, and at the bottom of the list, click Remove from Scaling Group.
   Manually remove managed instances	For a single instance: Find the instance that you want to remove. In the Actions column, click Remove from Scaling Group. For multiple instances: Select the instances that you want to remove, and at the bottom of the list, click Remove from Scaling Group.
   Manually delete ECS or ECI instances	For a single instance: Find the instance that you want to delete. In the Actions column, click >Delete Instance. For multiple instances: Select the instances that you want to delete, and at the bottom of the list, click Delete Instance. Note Deleting an instance removes it from the scaling group and releases it. Whether a manually added ECS instance or ECI instance can be deleted depends on its lifecycle management setting. For more information, see Manually added instances.

8. Choose whether to select Modify Expected Number of Instances (selected by default), and then click OK.

   • If you select Modify Expected Number of Instances, the expected instance count decreases by the number of instances removed.

   • If you do not select Modify Expected Number of Instances, the expected instance count remains unchanged after the instances are removed.

   Note

   When you manually remove or delete an ECS instance or ECI instance, you can also select the Automatically Disassociate The Instance From CLB (formerly SLB) And RDS instances option. If you select this option, the instance is automatically removed from the associated vServer groups or default server groups, and its IP address is removed from the RDS access whitelist.

Related topics

• You can manually adjust the status of instances, such as ECS instances, ECI instances, or managed instances, in a scaling group to meet your business needs. For example, you can manually change the state of an ECS instance in a scaling group to Stopped. During a scale-out activity, Auto Scaling starts stopped instances before it creates new ones. For more information, see Manually change the status of an instance.

• You can associate scaling groups with load balancer instances to distribute traffic across multiple instances in the scaling groups. This improves the service availability of your application. For more information, see Attach or detach load balancers.

• After you associate a scaling group with an RDS instance, the private IP addresses of ECS instances added to the scaling group are automatically added to the RDS instance's access whitelist. This allows for private network communication between the ECS instances and the RDS instance. For more information, see Add or remove RDS instances.