Manually Expanding Resources

Expand resources by manually adding instances to an AS group, removing instances from an AS group, or changing the expected number of instances.

If the AS group is enabled and has no scaling action being performed, and the number of instances is less than the maximum number of instances, you can manually add instances to the AS group.

Before adding instances to an AS group, ensure that the following conditions are met:

• The instances are not in other AS groups.
• The VPC of the instances to be added to the AS group must be the same as the VPC of the AS group.
• The AZ of the instances must be within the AZ of the AS group.
• After instances are added, the total number of instances is less than or equal to the maximum number of instances allowed.
• A batch operation can be performed on a maximum of 10 instances at a time.

To add instances to an AS group, perform the following steps:

1. Under Computing, click Auto Scaling.
2. Click the AS group name on the AS Groups tab.
3. On the Instances tab, click Add.
4. Select the instances to be added and click OK.

Removing instances from an AS group

You can remove an instance from an AS group, update the instance or rectify the instance fault, and add the instance to the AS group again. The instance removed out of the AS group does not carry application traffic any more.

For example, you can modify the AS configuration for an AS group at any time. However, the AS group does not allow the update of an instance that is running. In such an event, terminate the instance and replace it in the AS group. Alternatively, remove the instance out of the AS group, update the instance software, and add the instance to the AS group again.

Restrictions on instance removal are as follows:

• The AS group does not have a scaling action that is being performed, the instances are enabled, and the total number of instances after removal is not less than the minimum number of instances allowed.
• Instances manually added to an AS group can only be removed, and cannot be removed and deleted.
• A batch operation can be performed on a maximum of 10 instances at a time.

To remove an instance from an AS group, perform the following steps:

1. Under Computing, click Auto Scaling.
2. Click the AS group name on the AS Groups tab.
3. On the Instances tab, locate the row containing the target instance and click Remove or Remove and Delete in the Operation column.
4. To delete multiple instances from an AS group, select the check boxes in front of them and click Remove or Remove and Delete.

To delete all instances from an AS group, select the check box on the left of Instance Name and click Remove or Remove and Delete.

Changing the expected number of instances

Manually change the expected number of instances to add or reduce the number of instances in an AS group for expanding resources.

For details, see section Modifying an AS Group.