This topic describes how to manually add an Elastic Compute Service (ECS) instance or elastic container instance to a scaling group. You can add existing ECS instances or elastic container instances to a scaling group to fully use existing computing resources.

Prerequisites

The following table describes the requirements that the ECS instances or elastic container instances must meet to be manually added to a scaling group.
Item Prerequisites
ECS instances or elastic container instances to be added to the scaling group
  • The instances reside in the same region as the scaling group.
  • The instances are not added to other scaling groups.
  • The instances are in the Running state.
  • The network type of the instances is classic network or Virtual Private Cloud (VPC). Take note of the following items:
    • If the network type of the scaling group is classic network, only ECS instances or elastic container instances of the classic network type can be added to the scaling group.
    • If the network type of the scaling group is VPC, only ECS instances or elastic container instances in the same VPC as the scaling group can be added to the scaling group.
Scaling group
  • The scaling group is in the Enabled state.
  • The scaling group has no scaling activities in progress.

Background information

The active scaling configuration of a scaling group does not affect whether ECS instances or elastic container instances can be manually added to the scaling group. You can manually add ECS instances or elastic container instances without waiting for the cooldown period to expire. For more information about the cooldown time feature, see Cooldown time.

Auto Scaling attempts to create sufficient ECS instances or elastic container instances based on your configurations. However, if the instance inventory is insufficient or the sum of the instances to be added and the existing instances in the scaling group exceeds the maximum number of instances specified for the scaling group, the number of actually created instances may be less than the value that you specified. In these cases, check the configuration of the scaling group to troubleshoot the issue. If the issue persists, submit a ticket.

Procedure

In this example, ECS instances are used to show how to manually add instances to a scaling group. You can refer to this procedure to manually add elastic container instances to a 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 a scaling group and go to the details page of the scaling group. You can use one of the following methods to go to the details page:
    • Click the ID of the scaling group in the Scaling Group Name/ID column.
    • Click Details in the Actions column of the scaling group.
  5. In the upper part of the page, click the Instances tab.
  6. Click the Manually Added tab.
  7. Click Add Existing Instance.
  8. In the Add Existing Instance dialog box, select available ECS instances in the left-side list, click the Move icon to add the selected ECS instances to the right-side list, and then click Add.
    If you select Enable the scaling group to manage the instance lifecycle, ECS instances that are manually added to the scaling group will be removed and released during scale-in activities. Subscription instances can be manually added to a scaling group, but their lifecycle cannot be managed by the scaling group.
    Warning Make sure that you have sufficient balance in your account. If you have overdue payments in your account, pay-as-you-go and preemptible instances are stopped or released. For information about status changes of ECS instances in a scaling group due to overdue payments, see Overdue payments.
    After you manually add the ECS instances, you can view the added ECS instances and the information about the instances on the Manually Added tab.