**Example 1: To apply a target tracking scaling policy with a predefined metric specification** The following ``put-scaling-policy`` example applies a target tracking scaling policy with a predefined metric specification to an Amazon ECS service called web-app in the default cluster. The policy keeps the average CPU utilization of the service at 75 percent, with scale-out and scale-in cooldown periods of 60 seconds. The output contains the ARNs and names of the two CloudWatch alarms created on your behalf. Command: :: aws application-autoscaling put-scaling-policy --service-namespace ecs \ --scalable-dimension ecs:service:DesiredCount \ --resource-id service/default/web-app \ --policy-name cpu75-target-tracking-scaling-policy --policy-type TargetTrackingScaling \ --target-tracking-scaling-policy-configuration file://config.json This example assumes that you have a `config.json` file in the current directory with the following contents: :: { "TargetValue": 75.0, "PredefinedMetricSpecification": { "PredefinedMetricType": "ECSServiceAverageCPUUtilization" }, "ScaleOutCooldown": 60, "ScaleInCooldown": 60 } The command returns the following output: :: { "PolicyARN": "arn:aws:autoscaling:us-west-2:012345678910:scalingPolicy:6d8972f3-efc8-437c-92d1-6270f29a66e7:resource/ecs/service/default/web-app:policyName/cpu75-target-tracking-scaling-policy", "Alarms": [ { "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:TargetTracking-service/default/web-app-AlarmHigh-d4f0770c-b46e-434a-a60f-3b36d653feca", "AlarmName": "TargetTracking-service/default/web-app-AlarmHigh-d4f0770c-b46e-434a-a60f-3b36d653feca" }, { "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:TargetTracking-service/default/web-app-AlarmLow-1b437334-d19b-4a63-a812-6c67aaf2910d", "AlarmName": "TargetTracking-service/default/web-app-AlarmLow-1b437334-d19b-4a63-a812-6c67aaf2910d" } ] } For more information, see `Target Tracking Scaling Policies for Application Auto Scaling`_ in the *AWS Application Auto Scaling User Guide* .. _`Target Tracking Scaling Policies for Application Auto Scaling`: https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-target-tracking.html **Example 2: To apply a target tracking scaling policy with a customized metric specification** The following ``put-scaling-policy`` example applies a target tracking scaling policy with a customized metric specification to an Amazon ECS service called web-app in the default cluster. The policy keeps the average utilization of the service at 75 percent, with scale-out and scale-in cooldown periods of 60 seconds. The output contains the ARNs and names of the two CloudWatch alarms created on your behalf. Command: :: aws application-autoscaling put-scaling-policy --service-namespace ecs \ --scalable-dimension ecs:service:DesiredCount \ --resource-id service/default/web-app \ --policy-name cms75-target-tracking-scaling-policy --policy-type TargetTrackingScaling \ --target-tracking-scaling-policy-configuration file://config.json This example assumes that you have a `config.json` file in the current directory with the following contents: :: { "TargetValue":75.0, "CustomizedMetricSpecification":{ "MetricName":"MyUtilizationMetric", "Namespace":"MyNamespace", "Dimensions": [ { "Name":"MyOptionalMetricDimensionName", "Value":"MyOptionalMetricDimensionValue" } ], "Statistic":"Average", "Unit":"Percent" }, "ScaleOutCooldown": 60, "ScaleInCooldown": 60 } The command returns the following output: :: { "PolicyARN": "arn:aws:autoscaling:us-west-2:012345678910:scalingPolicy: 8784a896-b2ba-47a1-b08c-27301cc499a1:resource/ecs/service/default/web-app:policyName/cms75-target-tracking-scaling-policy", "Alarms": [ { "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:TargetTracking-service/default/web-app-AlarmHigh-9bc77b56-0571-4276-ba0f-d4178882e0a0", "AlarmName": "TargetTracking-service/default/web-app-AlarmHigh-9bc77b56-0571-4276-ba0f-d4178882e0a0" }, { "AlarmARN": "arn:aws:cloudwatch:us-west-2:012345678910:alarm:TargetTracking-service/default/web-app-AlarmLow-9b6ad934-6d37-438e-9e05-02836ddcbdc4", "AlarmName": "TargetTracking-service/default/web-app-AlarmLow-9b6ad934-6d37-438e-9e05-02836ddcbdc4" } ] } For more information, see `Target Tracking Scaling Policies for Application Auto Scaling`_ in the *AWS Application Auto Scaling User Guide*. .. _`Target Tracking Scaling Policies for Application Auto Scaling`: https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-target-tracking.html