putMetricAlarm method

Future<void> putMetricAlarm({

required String alarmName,
required ComparisonOperator comparisonOperator,
required int evaluationPeriods,
bool? actionsEnabled,
List<String>? alarmActions,
String? alarmDescription,
int? datapointsToAlarm,
List<Dimension>? dimensions,
String? evaluateLowSampleCountPercentile,
String? extendedStatistic,
List<String>? insufficientDataActions,
String? metricName,
List<MetricDataQuery>? metrics,
String? namespace,
List<String>? oKActions,
int? period,
Statistic? statistic,
List<Tag>? tags,
double? threshold,
String? thresholdMetricId,
String? treatMissingData,
StandardUnit? unit,

})

Creates or updates an alarm and associates it with the specified metric, metric math expression, or anomaly detection model.

Alarms based on anomaly detection models cannot have Auto Scaling actions.

When this operation creates an alarm, the alarm state is immediately set to INSUFFICIENT_DATA. The alarm is then evaluated and its state is set appropriately. Any actions associated with the new state are then executed.

When you update an existing alarm, its state is left unchanged, but the update completely overwrites the previous configuration of the alarm.

If you are an IAM user, you must have Amazon EC2 permissions for some alarm operations:

The iam:CreateServiceLinkedRole for all alarms with EC2 actions
The iam:CreateServiceLinkedRole to create an alarm with Systems Manager OpsItem actions.

The first time you create an alarm in the AWS Management Console, the CLI, or by using the PutMetricAlarm API, CloudWatch creates the necessary service-linked rolea for you. The service-linked roles are called AWSServiceRoleForCloudWatchEvents and AWSServiceRoleForCloudWatchAlarms_ActionSSM. For more information, see AWS service-linked role.

May throw LimitExceededFault.

Parameter alarmName : The name for the alarm. This name must be unique within the Region.

Parameter comparisonOperator : The arithmetic operation to use when comparing the specified statistic and threshold. The specified statistic value is used as the first operand.

The values LessThanLowerOrGreaterThanUpperThreshold, LessThanLowerThreshold, and GreaterThanUpperThreshold are used only for alarms based on anomaly detection models.

Parameter evaluationPeriods : The number of periods over which data is compared to the specified threshold. If you are setting an alarm that requires that a number of consecutive data points be breaching to trigger the alarm, this value specifies that number. If you are setting an "M out of N" alarm, this value is the N.

An alarm's total current evaluation period can be no longer than one day, so this number multiplied by Period cannot be more than 86,400 seconds.

Parameter actionsEnabled : Indicates whether actions should be executed during any changes to the alarm state. The default is TRUE.

Parameter alarmActions : The actions to execute when this alarm transitions to the ALARM state from any other state. Each action is specified as an Amazon Resource Name (ARN).

Valid Values: arn:aws:automate:region:ec2:stop | arn:aws:automate:region:ec2:terminate | arn:aws:automate:region:ec2:recover | arn:aws:automate:region:ec2:reboot | arn:aws:sns:region:account-id:sns-topic-name | arn:aws:autoscaling:region:account-id:scalingPolicy:policy-id:autoScalingGroupName/group-friendly-name:policyName/policy-friendly-name | arn:aws:ssm:region:account-id:opsitem:severity

Valid Values (for use with IAM roles): arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Stop/1.0 | arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Terminate/1.0 | arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Reboot/1.0

Parameter alarmDescription : The description for the alarm.

Parameter datapointsToAlarm : The number of data points that must be breaching to trigger the alarm. This is used only if you are setting an "M out of N" alarm. In that case, this value is the M. For more information, see Evaluating an Alarm in the Amazon CloudWatch User Guide.

Parameter dimensions : The dimensions for the metric specified in MetricName.

Parameter evaluateLowSampleCountPercentile : Used only for alarms based on percentiles. If you specify ignore, the alarm state does not change during periods with too few data points to be statistically significant. If you specify evaluate or omit this parameter, the alarm is always evaluated and possibly changes state no matter how many data points are available. For more information, see Percentile-Based CloudWatch Alarms and Low Data Samples.

Valid Values: evaluate | ignore

Parameter extendedStatistic : The percentile statistic for the metric specified in MetricName. Specify a value between p0.0 and p100. When you call PutMetricAlarm and specify a MetricName, you must specify either Statistic or ExtendedStatistic, but not both.

Parameter insufficientDataActions : The actions to execute when this alarm transitions to the INSUFFICIENT_DATA state from any other state. Each action is specified as an Amazon Resource Name (ARN).

Valid Values (for use with IAM roles): >arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Stop/1.0 | arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Terminate/1.0 | arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Reboot/1.0

Parameter metricName : The name for the metric associated with the alarm. For each PutMetricAlarm operation, you must specify either MetricName or a Metrics array.

If you are creating an alarm based on a math expression, you cannot specify this parameter, or any of the Dimensions, Period, Namespace, Statistic, or ExtendedStatistic parameters. Instead, you specify all this information in the Metrics array.

Parameter metrics : An array of MetricDataQuery structures that enable you to create an alarm based on the result of a metric math expression. For each PutMetricAlarm operation, you must specify either MetricName or a Metrics array.

Each item in the Metrics array either retrieves a metric or performs a math expression.

One item in the Metrics array is the expression that the alarm watches. You designate this expression by setting ReturnData to true for this object in the array. For more information, see MetricDataQuery.

If you use the Metrics parameter, you cannot include the MetricName, Dimensions, Period, Namespace, Statistic, or ExtendedStatistic parameters of PutMetricAlarm in the same operation. Instead, you retrieve the metrics you are using in your math expression as part of the Metrics array.

Parameter namespace : The namespace for the metric associated specified in MetricName.

Parameter oKActions : The actions to execute when this alarm transitions to an OK state from any other state. Each action is specified as an Amazon Resource Name (ARN).

Parameter period : The length, in seconds, used each time the metric specified in MetricName is evaluated. Valid values are 10, 30, and any multiple of 60.

Period is required for alarms based on static thresholds. If you are creating an alarm based on a metric math expression, you specify the period for each metric within the objects in the Metrics array.

Be sure to specify 10 or 30 only for metrics that are stored by a PutMetricData call with a StorageResolution of

If you specify a period of 10 or 30 for a metric that does not have sub-minute resolution, the alarm still attempts to gather data at the period rate that you specify. In this case, it does not receive data for the attempts that do not correspond to a one-minute data resolution, and the alarm might often lapse into INSUFFICENT_DATA status. Specifying 10 or 30 also sets this alarm as a high-resolution alarm, which has a higher charge than other alarms. For more information about pricing, see Amazon CloudWatch Pricing.

An alarm's total current evaluation period can be no longer than one day, so Period multiplied by EvaluationPeriods cannot be more than 86,400 seconds.

Parameter statistic : The statistic for the metric specified in MetricName, other than percentile. For percentile statistics, use ExtendedStatistic. When you call PutMetricAlarm and specify a MetricName, you must specify either Statistic or ExtendedStatistic, but not both.

Parameter tags : A list of key-value pairs to associate with the alarm. You can associate as many as 50 tags with an alarm.

Tags can help you organize and categorize your resources. You can also use them to scope user permissions by granting a user permission to access or change only resources with certain tag values.

If you are using this operation to update an existing alarm, any tags you specify in this parameter are ignored. To change the tags of an existing alarm, use TagResource or UntagResource.

Parameter threshold : The value against which the specified statistic is compared.

This parameter is required for alarms based on static thresholds, but should not be used for alarms based on anomaly detection models.

Parameter thresholdMetricId : If this is an alarm based on an anomaly detection model, make this value match the ID of the ANOMALY_DETECTION_BAND function.

For an example of how to use this parameter, see the Anomaly Detection Model Alarm example on this page.

If your alarm uses this parameter, it cannot have Auto Scaling actions.

Parameter treatMissingData : Sets how this alarm is to handle missing data points. If TreatMissingData is omitted, the default behavior of missing is used. For more information, see Configuring How CloudWatch Alarms Treats Missing Data.

Valid Values: breaching | notBreaching | ignore | missing

Parameter unit : The unit of measure for the statistic. For example, the units for the Amazon EC2 NetworkIn metric are Bytes because NetworkIn tracks the number of bytes that an instance receives on all network interfaces. You can also specify a unit when you create a custom metric. Units help provide conceptual meaning to your data. Metric data points that specify a unit of measure, such as Percent, are aggregated separately.

If you don't specify Unit, CloudWatch retrieves all unit types that have been published for the metric and attempts to evaluate the alarm. Usually, metrics are published with only one unit, so the alarm works as intended.

However, if the metric is published with multiple types of units and you don't specify a unit, the alarm's behavior is not defined and it behaves predictably.

We recommend omitting Unit so that you don't inadvertently specify an incorrect unit that is not published for this metric. Doing so causes the alarm to be stuck in the INSUFFICIENT DATA state.

Implementation

Future<void> putMetricAlarm({
  required String alarmName,
  required ComparisonOperator comparisonOperator,
  required int evaluationPeriods,
  bool? actionsEnabled,
  List<String>? alarmActions,
  String? alarmDescription,
  int? datapointsToAlarm,
  List<Dimension>? dimensions,
  String? evaluateLowSampleCountPercentile,
  String? extendedStatistic,
  List<String>? insufficientDataActions,
  String? metricName,
  List<MetricDataQuery>? metrics,
  String? namespace,
  List<String>? oKActions,
  int? period,
  Statistic? statistic,
  List<Tag>? tags,
  double? threshold,
  String? thresholdMetricId,
  String? treatMissingData,
  StandardUnit? unit,
}) async {
  ArgumentError.checkNotNull(alarmName, 'alarmName');
  _s.validateStringLength(
    'alarmName',
    alarmName,
    1,
    255,
    isRequired: true,
  );
  ArgumentError.checkNotNull(comparisonOperator, 'comparisonOperator');
  ArgumentError.checkNotNull(evaluationPeriods, 'evaluationPeriods');
  _s.validateNumRange(
    'evaluationPeriods',
    evaluationPeriods,
    1,
    1152921504606846976,
    isRequired: true,
  );
  _s.validateStringLength(
    'alarmDescription',
    alarmDescription,
    0,
    1024,
  );
  _s.validateNumRange(
    'datapointsToAlarm',
    datapointsToAlarm,
    1,
    1152921504606846976,
  );
  _s.validateStringLength(
    'evaluateLowSampleCountPercentile',
    evaluateLowSampleCountPercentile,
    1,
    255,
  );
  _s.validateStringLength(
    'metricName',
    metricName,
    1,
    255,
  );
  _s.validateStringLength(
    'namespace',
    namespace,
    1,
    255,
  );
  _s.validateNumRange(
    'period',
    period,
    1,
    1152921504606846976,
  );
  _s.validateStringLength(
    'thresholdMetricId',
    thresholdMetricId,
    1,
    255,
  );
  _s.validateStringLength(
    'treatMissingData',
    treatMissingData,
    1,
    255,
  );
  final $request = <String, dynamic>{};
  $request['AlarmName'] = alarmName;
  $request['ComparisonOperator'] = comparisonOperator.toValue();
  $request['EvaluationPeriods'] = evaluationPeriods;
  actionsEnabled?.also((arg) => $request['ActionsEnabled'] = arg);
  alarmActions?.also((arg) => $request['AlarmActions'] = arg);
  alarmDescription?.also((arg) => $request['AlarmDescription'] = arg);
  datapointsToAlarm?.also((arg) => $request['DatapointsToAlarm'] = arg);
  dimensions?.also((arg) => $request['Dimensions'] = arg);
  evaluateLowSampleCountPercentile
      ?.also((arg) => $request['EvaluateLowSampleCountPercentile'] = arg);
  extendedStatistic?.also((arg) => $request['ExtendedStatistic'] = arg);
  insufficientDataActions
      ?.also((arg) => $request['InsufficientDataActions'] = arg);
  metricName?.also((arg) => $request['MetricName'] = arg);
  metrics?.also((arg) => $request['Metrics'] = arg);
  namespace?.also((arg) => $request['Namespace'] = arg);
  oKActions?.also((arg) => $request['OKActions'] = arg);
  period?.also((arg) => $request['Period'] = arg);
  statistic?.also((arg) => $request['Statistic'] = arg.toValue());
  tags?.also((arg) => $request['Tags'] = arg);
  threshold?.also((arg) => $request['Threshold'] = arg);
  thresholdMetricId?.also((arg) => $request['ThresholdMetricId'] = arg);
  treatMissingData?.also((arg) => $request['TreatMissingData'] = arg);
  unit?.also((arg) => $request['Unit'] = arg.toValue());
  await _protocol.send(
    $request,
    action: 'PutMetricAlarm',
    version: '2010-08-01',
    method: 'POST',
    requestUri: '/',
    exceptionFnMap: _exceptionFns,
    shape: shapes['PutMetricAlarmInput'],
    shapes: shapes,
  );
}

putMetricAlarm method

Implementation

CloudWatch class