This topic describes how to remove an Elastic Compute Service (ECS) instance from the Standby state. After the ECS instance is removed from the Standby state, the ECS instance enters the In Service state and resumes to provide services.

Background information

You can remove an ECS instance from the Standby state by using one of the following methods:
  • Synchronously remove the ECS instance from the Standby state: Auto Scaling receives and handles the request to remove the ECS instance from the Standby state in the backend. If your scaling group contains a large amount of resources, the synchronization operation takes a long time, which may causes timeout errors. In this case, we recommend that you asynchronously remove the ECS instance from the Standby state.
  • Asynchronously remove the ECS instance from the Standby state: A scaling activity is immediately triggered after you select the Asynchronously Remove from Standby option in the Auto Scaling console. You can view the result of the scaling activity on the Scaling Activities tab. Compared with the synchronous operation, the asynchronous operation brings a better interactive experience to users.
After an ECS instance in a scaling group is removed from the Standby state:
  • The ECS instance enters the In Service state.
  • If the scaling group to which the ECS instance is added is associated with a Server Load Balancer (SLB) instance, the default weight of the ECS instance as the backend server of the SLB instance is 50 when the ECS instance is attached to the SLB instance again.
  • When the ECS instance is stopped or restarted, the health check status of the instance is updated.
  • When a scale-in activity is triggered in the scaling group, Auto Scaling can remove the ECS instance from the scaling group.
    Note If the lifecycle of the ECS instance that is removed from the Standby state is managed by the scaling group, Auto Scaling releases the ECS instance. If the lifecycle of the ECS instances is not managed by the scaling group, the ECS instance can still run as expected. For information about how to manage the lifecycle of ECS instances, see ECS instance lifecycle in a scaling group.

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 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. Select the source of an ECS instance.
    • To select an ECS instance that is automatically created, click the Auto Created tab.
    • To select an ECS instance that is manually added, click the Manually Added tab.
  7. Remove an ECS instance from the Standby state by using one of the following methods.
    • Find the ECS instance that you want to remove from the Standby state and click Remove from Standby in the Actions column.
    • Select one or more ECS instances that you want to remove from the Standby state and click Remove from Standby in the lower part of the Instances page.
  8. In the Remove from Standby dialog box, select a method to remove the ECS instance from the Standby state.
    • Synchronously remove the ECS instance from the Standby state: Click OK.
    • Asynchronously remove the ECS instance from the Standby state: Select Asynchronously Remove from Standby, and then click OK.

      On the Scaling Rules and Activities tab, click Scaling Activities and view whether the instance is removed from the Standby state.