This topic describes how to switch an Elastic Compute Service (ECS) instance to the Standby state. If you do not need to use an ECS instance for the moment, you can switch the instance to the Standby state. After an ECS instance is switched to the Standby state, the load balancing weight of the ECS instance changes to zero. If an ECS instance is in the Standby state, Auto Scaling neither checks its health status nor releases it.

Background information

After an ECS instance is switched to the Standby state:
  • If a Server Load Balancer (SLB) instance is attached to the scaling group to which the ECS instance belongs, the load balancing weight of the ECS instance changes to zero.
  • The ECS instance stays in the Standby state until you manually remove it from the Standby state.
  • Auto Scaling stops managing the lifecycle of the ECS instance. You must manually manage the lifecycle of the ECS instance.
  • If a scale-in activity is triggered, Auto Scaling skips this ECS instance when selecting the ECS instances to remove.
  • When the ECS instance is stopped or restarted, its health check status remains unchanged.
  • To release the ECS instance, you must first remove it from the scaling group.
  • If you delete the scaling group, the ECS instance is removed from the Standby state and released.
  • You can stop the ECS instance or modify its configurations. For example, you can perform the following operations:

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. You can use either of the following methods to open the details page of a scaling group.
    • In the Scaling Group Name/ID column, click a scaling group name.
    • Click Manage in the Actions column corresponding to a scaling group.
  5. In the left-side navigation pane, click ECS Instances.
  6. Select the source of the ECS instance.
    • To select an automatically created ECS instance, click the Auto Created tab.
    • To select a manually added ECS instance, click the Manually Added tab.
  7. Switch one or more ECS instances to the Standby state.
    • To switch a single ECS instance to the Standby state, find the target ECS instance and choose More > Switch to Standby State in the Actions column.
    • To switch multiple ECS instances to the Standby state at the same time, select the target ECS instances and click Switch to Standby State under the ECS instance list.
  8. Click OK.