Workflow Actions
AWS: Update ASG Configuration Values
Updates Auto Scaling Group settings such as minimum size, maximum size, desired capacity, or launch template version as needed.
Availability
Description
Premium. This action is a Premium Workflow Action, billed separately from your PagerDuty plan. In the workflow action picker, this action appears as Auto Scaling: Update Auto Scaling Group.
Update Auto Scaling Group (ASG) configuration values such as min size, max size, desired capacity, or launch template. Only the fields you provide are changed; others are left unchanged. This action is useful for:
- Temporarily bumping max size during instance rotation so the ASG can launch a replacement before the old instance is terminated
- Scaling up desired capacity during a load incident (often combined with Describe Auto Scaling Groups to read current values first)
- Updating the launch template version for rolling updates or remediation
- Automating capacity changes in runbooks based on incident or prior-step outputs
Instructions
- If you have not done so, follow the instructions to Create an Incident Workflow.
- When the instructions prompt you to add actions, select this action.
- Enter the following Inputs and click Save.
- Continue following instructions to Publish the Workflow.
- When the action runs, you will see the Outputs listed below.
Inputs
Field References
Fields with the {+} icon accept Field References, which can be useful for referencing incident data or outputs created in prior workflow steps. To add Field References, click {+}, or enter {{, and select relevant fields. Refer to the Field References article for more information.
| Name | Description |
|---|---|
| Integration | Select a Workflow Integration or click New AWS Connection to establish a new one. |
| Auto Scaling Group Name | The name of the Auto Scaling Group to update. |
| AWS Region | The AWS region where the Auto Scaling Group is located. If left blank, the action uses us-east-1 as the default. |
| Minimum Size | (Optional.) New minimum size. Omit to leave unchanged. |
| Maximum Size | (Optional.) New maximum size. Omit to leave unchanged. |
| Desired Capacity | (Optional.) New desired capacity. Omit to leave unchanged. |
| New Launch Template | (Optional.) Launch template to switch to. Can include Launch Template ID, Launch Template Name, and Version. Omit to leave the current launch template unchanged. |
Outputs
| Name | Description |
|---|---|
| ASG Name | The Auto Scaling Group that was updated. |
| Applied | JSON object of the values that were sent (minSize, maxSize, desiredCapacity, launchTemplate) for auditability. |
| Result | Whether the action succeeded: Success or Failed. |
| Result Summary | Brief description of what the action did or if it failed. |
| Error | Error message, if the action failed. |
Tips
- Partial Updates: Only include inputs you want to change; omitting Minimum Size, Maximum Size, Desired Capacity, or New Launch Template leaves those settings unchanged.
- Instance Rotation: For rotate-instance workflows, use Describe Auto Scaling Groups and a Logic step first to compute the new max size, then pass it into this action's Maximum Size input.