You can execute a scaling rule for a scaling group given the following conditions:
- The scaling group is active.
- The scaling group is not executing any scaling activity.
If no scaling activity is being executed for the scaling group, the scaling rule is executed directly without waiting for the cool-down time.
A successful return indicates that Auto Scaling will shortly execute the scaling activity, but does not mean the scaling activity will be successfully executed. Use the returned ScalingActivityID to check the status of the scaling activity.
- If the number of ECS instances to be added by the scaling rule plus the number of existing ECS instances in the group (Total Capacity) exceeds the MaxSize value, the Total Capacity is adjusted to the MaxSize value.
- If the number of existing ECS instances in the scaling group (Total Capacity) minus the number of ECS instances to be removed by the scaling rule is less than the MinSize value, the Total Capacity is adjusted to the MinSize value.
Up to 1,000 ECS instances are supported for auto scaling for all scaling groups in all regions. This restriction applies only to ECS instances that were automatically created, not those manually added.
On the Scaling group management page, click Manage next to the group to be managed.
Click Scaling rule on the left side, and then click Execute next to the scaling rule to be executed.