A cooldown period is a temporary lockout interval following a successful scaling event initiated by an event-triggered task in a scaling group. This mechanism prevents additional scaling requests initiated by other event-triggered tasks during the cooldown window, thereby regulating scaling frequency.
Overview
A cooldown period defines the minimum required waiting time between two consecutive scaling events triggered by event-triggered tasks. During this period, any new scaling requests from event-triggered tasks will be automatically rejected.
When a cooldown period is configured, Auto Scaling rejects only scaling requests from event-triggered tasks. Scaling requests from manual execution of scheduled tasks or adjustments to the expected/minimum/maximum instance count are unaffected and can proceed normally.
Classification
Default Cooldown Time (Seconds): specifies the default cooldown period of scaling groups.
Cooldown Time: specifies the cooldown period of simple scaling rules that are defined in event-triggered tasks. If you do not configure this parameter, the value of the Default Cooldown Time (Seconds) parameter is automatically used.
Applicable scope
The cooldown period feature is applicable to scaling operations that are triggered by event-triggered tasks of the system monitoring type.
Calculation rules
Start time: After a scaling operation is triggered, the cooldown period begins when the last instance is added to or removed from the scaling group. If no instance is added to or removed from the scaling group after a scaling operation is triggered, the cooldown period does not begin.
You can configure the Default Cooldown Time (Seconds) and Cooldown Time parameters at the same time. In this case, the value of the Cooldown Time parameter takes priority.
ImportantDisabling and re-enabling a scaling group resets the cooldown period, so the first scaling operation afterward is not restricted by the previous cooldown period.
Configure a cooldown period
Configure the Default Cooldown Time (Seconds) parameter of a scaling group
Modify the Default Cooldown Time (Seconds) parameter of an existing scaling group
Log on to the Auto Scaling console.
In the left-side navigation pane, click Scaling Groups.
In the top navigation bar, select the region where Auto Scaling is activated.
On the Scaling Groups page, find the scaling group whose Default Cooldown Time (Seconds) parameter you want to modify and click Details in the Actions column to go to the scaling group details page. In the Instance Scaling Overview section, click the
icon to open the Edit Instance Scaling Overview dialog box. Modify the Default Cooldown Time (Seconds) parameter based on your business requirements.
Click OK.
Configure the Default Cooldown Time (Seconds) parameter when you create a scaling group
When you create a scaling group on the Create by Form tab, you can configure the Default Cooldown Time (Seconds) parameter based on your business requirements, as shown in the following figure.
For information about how to create a scaling group, see Create a scaling group of the ECS type or Create a scaling group of the Elastic Container Instance type.
Configure the Cooldown Time parameter of a simple scaling rule
Modify the Cooldown Time parameter of an existing simple scaling rule
Log on to the Auto Scaling console.
In the left-side navigation pane, click Scaling Groups.
In the top navigation bar, select the region where Auto Scaling is activated.
On the Scaling Groups page, find the scaling group whose simple scaling rule you want to manage and click Details in the Actions column to go to the scaling group details page.
Choose . Find the scaling rule that you want to manage and click Edit in the Actions column to open the Edit Scaling Rule dialog box.
Modify the Cooldown Time parameter based on your business requirements.
Click OK.
Configure the Cooldown Time parameter when you create a simple scaling rule
When you create a simple scaling rule, you can configure the Cooldown Time parameter based on your business requirements, as shown in the following figure.
For more information about how to create a scaling rule, see Configure scaling rules.
References
For information about how to modify the default cooldown period of a scaling group by calling an API operation, see ModifyScalingGroup.
For information about how to modify the cooldown period of a simple scaling rule by calling an API operation, see ModifyScalingRule.