You can create a CloudWatch alarm using a resource’s metric, and then add an action using the action’s dedicated Amazon Resource Name (ARN). You can add the action to any alarm state.
Eucalyptus currently only supports actions for executing Auto Scaling policies.
Enter the following command:
euwatch-put-metric-alarm [alarm_name] --unit Percent --namespace "AWS/EC2"
-- dimensions "InstanceId=[instance_id]" --statistic [statistic] --metric-name
[metric] --comparison-operator [operator] --threshold [value] --period
[seconds] --evaluation-periods [value] -- alarm-actions [action]
For example, the following triggers an Auto Scaling policy if the average CPUUtilization is less than 10 percent over a 24 hour period.
euwatch-put-metric-alarm test-Alarm --unit Percent --namespace "AWS/EC2"
-- dimensions "InstanceId=i-abc123" --statistic Average --metric-name CPUUtilization
--comparison-operator LessThanThreshold --threshold 10 --period 86400
--evaluation-periods 4 -- alarm-actions arn:aws:autoscaling::429942273585:scalingPolicy:
12ad560b-58b2-4051-a6d3-80e53b674de4:autoScalingGroupName/testgroup01:
policyName/testgroup01-pol01