Create an alarm that uses a warm-up period
Create a metric alarm or log alarm with a warm-up period to delay evaluation after creation. For more information about warm-up periods, see Alarm warm-up periods.
Set the warm-up period with the WarmUpConfiguration
parameter on the PutMetricAlarm API. Log alarms
use the PutLogAlarm API.
Creating a warm-up alarm with the Amazon CLI
The following examples create and manage alarms with warm-up periods.
Example Create a metric alarm with a 30-minute warm-up period
This alarm uses default early-termination behavior: it ends warm-up and begins to evaluate as soon as enough data fills the evaluation window.
aws cloudwatch put-metric-alarm \ --alarm-name MyServiceStartupAlarm \ --metric-name CPUUtilization \ --namespace AWS/EC2 \ --statistic Average \ --period 300 \ --evaluation-periods 1 \ --threshold 80 \ --comparison-operator GreaterThanThreshold \ --dimensions Name=InstanceId,Value=i-1234567890abcdef0 \ --warm-up-configuration '{"WarmUpPeriodDurationInMinutes":30}'
Example Wait the entire warm-up period before evaluating
Set OnlyStartEvaluatingAfterWarmUpPeriodEnds to
true to prevent evaluation until the full warm-up
duration elapses. The alarm waits the full 60 minutes before it evaluates,
even if data arrives sooner.
aws cloudwatch put-metric-alarm \ --alarm-name MyServiceStartupAlarm \ --metric-name CPUUtilization \ --namespace AWS/EC2 \ --statistic Average \ --period 300 \ --evaluation-periods 1 \ --threshold 80 \ --comparison-operator GreaterThanThreshold \ --dimensions Name=InstanceId,Value=i-1234567890abcdef0 \ --warm-up-configuration '{"WarmUpPeriodDurationInMinutes":60,"OnlyStartEvaluatingAfterWarmUpPeriodEnds":true}'
Example Change the warm-up period while the alarm is warming up
You can update the warm-up configuration while the alarm is still in its warm-up period. This example sets the warm-up duration to 45 minutes.
aws cloudwatch put-metric-alarm \ --alarm-name MyServiceStartupAlarm \ --metric-name CPUUtilization \ --namespace AWS/EC2 \ --statistic Average \ --period 300 \ --evaluation-periods 1 \ --threshold 80 \ --comparison-operator GreaterThanThreshold \ --dimensions Name=InstanceId,Value=i-1234567890abcdef0 \ --warm-up-configuration '{"WarmUpPeriodDurationInMinutes":45}'
Note
After the warm-up period ends, you can update the warm-up configuration. However, the update does not start a new warm-up period. The alarm continues to evaluate normally.
View the warm-up configuration
Use the DescribeAlarms API to retrieve an alarm's warm-up configuration.
aws cloudwatch describe-alarms \ --alarm-names MyServiceStartupAlarm
During warm-up, the alarm state remains
INSUFFICIENT_DATA and the evaluation state is
IN_WARM_UP.