Creates or updates a policy for an existing Application Auto Scaling scalable target. Each scalable target is identified by service namespace, a resource ID, and a scalable dimension, and a scaling policy applies to a scalable target that is identified by those three attributes. You cannot create a scaling policy without first registering a scalable target with RegisterScalableTarget.
To update an existing policy, use the existing policy name and set the parameters you want to change. Any existing parameter not changed in an update to an existing policy is not changed in this update request.
You can view the existing scaling policies for a service namespace with DescribeScalingPolicies. If you are no longer using a scaling policy, you can delete it with DeleteScalingPolicy.