PutMetricAlarm - Amazon CloudWatch
Request ParametersErrorsExamplesSee Also

PutMetricAlarm

Creates or updates an alarm and associates it with the specified metric, metric math expression, anomaly detection model, or Metrics Insights query. For more information about using a Metrics Insights query for an alarm, see Create alarms on Metrics Insights queries.

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 permission for all alarms with EC2 actions

  • The iam:CreateServiceLinkedRole permissions to create an alarm with Systems Manager OpsItem or response plan actions.

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

Each PutMetricAlarm action has a maximum uncompressed payload of 120 KB.

Cross-account alarms

You can set an alarm on metrics in the current account, or in another account. To create a cross-account alarm that watches a metric in a different account, you must have completed the following pre-requisites:

  • The account where the metrics are located (the sharing account) must already have a sharing role named CloudWatch-CrossAccountSharingRole. If it does not already have this role, you must create it using the instructions in Set up a sharing account in Cross-account cross-Region CloudWatch console. The policy for that role must grant access to the ID of the account where you are creating the alarm.

  • The account where you are creating the alarm (the monitoring account) must already have a service-linked role named AWSServiceRoleForCloudWatchCrossAccount to allow CloudWatch to assume the sharing role in the sharing account. If it does not, you must create it following the directions in Set up a monitoring account in Cross-account cross-Region CloudWatch console.

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

ActionsEnabled

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

Type: Boolean

Required: No

AlarmActions.member.N

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:

EC2 actions:

  • arn:aws:automate:region:ec2:stop

  • arn:aws:automate:region:ec2:terminate

  • arn:aws:automate:region:ec2:reboot

  • arn:aws:automate:region:ec2:recover

  • 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

  • arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Recover/1.0

Autoscaling action:

  • arn:aws:autoscaling:region:account-id:scalingPolicy:policy-id:autoScalingGroupName/group-friendly-name:policyName/policy-friendly-name

Lambda actions:

  • Invoke the latest version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name

  • Invoke a specific version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name:version-number

  • Invoke a function by using an alias Lambda function: arn:aws:lambda:region:account-id:function:function-name:alias-name

SNS notification action:

  • arn:aws:sns:region:account-id:sns-topic-name

SSM integration actions:

  • arn:aws:ssm:region:account-id:opsitem:severity#CATEGORY=category-name

  • arn:aws:ssm-incidents::account-id:responseplan/response-plan-name

Type: Array of strings

Array Members: Maximum number of 5 items.

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: No

AlarmDescription

The description for the alarm.

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1024.

Required: No

AlarmName

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

The name must contain only UTF-8 characters, and can't contain ASCII control characters

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: Yes

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.

Type: String

Valid Values: GreaterThanOrEqualToThreshold | GreaterThanThreshold | LessThanThreshold | LessThanOrEqualToThreshold | LessThanLowerOrGreaterThanUpperThreshold | LessThanLowerThreshold | GreaterThanUpperThreshold

Required: Yes

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.

Type: Integer

Valid Range: Minimum value of 1.

Required: No

Dimensions.member.N

The dimensions for the metric specified in MetricName.

Type: Array of Dimension objects

Array Members: Maximum number of 30 items.

Required: No

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

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: No

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.

Type: Integer

Valid Range: Minimum value of 1.

Required: Yes

ExtendedStatistic

The extended statistic for the metric specified in MetricName. When you call PutMetricAlarm and specify a MetricName, you must specify either Statistic or ExtendedStatistic but not both.

If you specify ExtendedStatistic, the following are valid values:

  • p90

  • tm90

  • tc90

  • ts90

  • wm90

  • IQM

  • PR(n:m) where n and m are values of the metric

  • TC(X%:X%) where X is between 10 and 90 inclusive.

  • TM(X%:X%) where X is between 10 and 90 inclusive.

  • TS(X%:X%) where X is between 10 and 90 inclusive.

  • WM(X%:X%) where X is between 10 and 90 inclusive.

For more information about these extended statistics, see CloudWatch statistics definitions.

Type: String

Required: No

InsufficientDataActions.member.N

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:

EC2 actions:

  • arn:aws:automate:region:ec2:stop

  • arn:aws:automate:region:ec2:terminate

  • arn:aws:automate:region:ec2:reboot

  • arn:aws:automate:region:ec2:recover

  • 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

  • arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Recover/1.0

Autoscaling action:

  • arn:aws:autoscaling:region:account-id:scalingPolicy:policy-id:autoScalingGroupName/group-friendly-name:policyName/policy-friendly-name

Lambda actions:

  • Invoke the latest version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name

  • Invoke a specific version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name:version-number

  • Invoke a function by using an alias Lambda function: arn:aws:lambda:region:account-id:function:function-name:alias-name

SNS notification action:

  • arn:aws:sns:region:account-id:sns-topic-name

SSM integration actions:

  • arn:aws:ssm:region:account-id:opsitem:severity#CATEGORY=category-name

  • arn:aws:ssm-incidents::account-id:responseplan/response-plan-name

Type: Array of strings

Array Members: Maximum number of 5 items.

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: No

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 Namespace, Dimensions, Period, Unit, Statistic, or ExtendedStatistic parameters. Instead, you specify all this information in the Metrics array.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: No

Metrics.member.N

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 Namespace, MetricName, Dimensions, Period, Unit, 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.

Type: Array of MetricDataQuery objects

Required: No

Namespace

The namespace for the metric associated specified in MetricName.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Pattern: [^:].*

Required: No

OKActions.member.N

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). Valid values:

EC2 actions:

  • arn:aws:automate:region:ec2:stop

  • arn:aws:automate:region:ec2:terminate

  • arn:aws:automate:region:ec2:reboot

  • arn:aws:automate:region:ec2:recover

  • 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

  • arn:aws:swf:region:account-id:action/actions/AWS_EC2.InstanceId.Recover/1.0

Autoscaling action:

  • arn:aws:autoscaling:region:account-id:scalingPolicy:policy-id:autoScalingGroupName/group-friendly-name:policyName/policy-friendly-name

Lambda actions:

  • Invoke the latest version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name

  • Invoke a specific version of a Lambda function: arn:aws:lambda:region:account-id:function:function-name:version-number

  • Invoke a function by using an alias Lambda function: arn:aws:lambda:region:account-id:function:function-name:alias-name

SNS notification action:

  • arn:aws:sns:region:account-id:sns-topic-name

SSM integration actions:

  • arn:aws:ssm:region:account-id:opsitem:severity#CATEGORY=category-name

  • arn:aws:ssm-incidents::account-id:responseplan/response-plan-name

Type: Array of strings

Array Members: Maximum number of 5 items.

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: No

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 1. 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.

Type: Integer

Valid Range: Minimum value of 10.

Required: No

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.

Type: String

Valid Values: SampleCount | Average | Sum | Minimum | Maximum

Required: No

Tags.member.N

A list of key-value pairs to associate with the alarm. You can associate as many as 50 tags with an alarm. To be able to associate tags with the alarm when you create the alarm, you must have the cloudwatch:TagResource permission.

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.

To use this field to set tags for an alarm when you create it, you must be signed on with both the cloudwatch:PutMetricAlarm and cloudwatch:TagResource permissions.

Type: Array of Tag objects

Required: No

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.

Type: Double

Required: No

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.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: No

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

Note

Alarms that evaluate metrics in the AWS/DynamoDB namespace always ignore missing data even if you choose a different option for TreatMissingData. When an AWS/DynamoDB metric has missing data, alarms that evaluate that metric remain in their current state.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Required: No

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 are creating an alarm based on a metric math expression, you can specify the unit for each metric (if needed) within the objects in the Metrics array.

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 unpredictably.

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.

Type: String

Valid Values: Seconds | Microseconds | Milliseconds | Bytes | Kilobytes | Megabytes | Gigabytes | Terabytes | Bits | Kilobits | Megabits | Gigabits | Terabits | Percent | Count | Bytes/Second | Kilobytes/Second | Megabytes/Second | Gigabytes/Second | Terabytes/Second | Bits/Second | Kilobits/Second | Megabits/Second | Gigabits/Second | Terabits/Second | Count/Second | None

Required: No

Errors

For information about the errors that are common to all actions, see Common Errors.

LimitExceeded

The quota for alarms for this customer has already been reached.

HTTP Status Code: 400

Examples

Static Threshold Alarm

The following example creates an alarm that notifies an SNS group when the CPUUtilization of a certain instance goes over 40% for three out of four periods.

Sample Request

{
    "Namespace": "AWS/EC2",
    "MetricName": "CPUUtilization",
    "Dimensions": [
        {
            "Name": "InstanceId",
            "Value": "i-1234567890abcdef0"
        }
    ],
    "AlarmActions": [
        "arn:aws:sns:us-west-1:123456789012:my_sns_topic"
    ],
    "ComparisonOperator": "GreaterThanThreshold",
    "DatapointsToAlarm": 3,
    "EvaluationPeriods": 4,
    "Period": 60,
    "Statistic": "Average",
    "Threshold": 40,
    "AlarmDescription": "CPU Utilization of i-1234567890abcdef0 with 40% as threshold",
    "AlarmName": "Instance i-1234567890abcdef0 CPU Utilization"
}

Metric Math Function Alarm

The following example retrieves three metrics that each track a different type of connection error to a custom service. These error counts are first summed in one expression, then divided by total connection attempts in another expression. The alarm goes to the ALARM state if the error rate is over 3% for two consecutive periods, and notifies two different SNS groups.

Sample Request

{
    "AlarmActions": [
        "arn:aws:sns:us-west-1:123456789012:my_sns_topic",
        "arn:aws:sns:us-west-1:123456789012:my_other_sns_topic"
    ],
    "ComparisonOperator": "GreaterThanThreshold",
    "EvaluationPeriods": 3,
    "Threshold": 40,
    "AlarmDescription": "MyService Aggregate Connection Error Rate (Alarm at 3%)",
    "AlarmName": "MyService Connection Error Rate",
    "Metrics": [
        {
            "MetricStat": {
                "Metric": {
                    "MetricName": "ConnectionsFailed",
                    "Namespace": "MyService"
                },
                "Period": 60,
                "Stat": "Sum"
            },
            "Id": "m1",
            "ReturnData": "False"
        },
        {
            "MetricStat": {
                "Metric": {
                    "MetricName": "ConnectionsDropped",
                    "Namespace": "MyService"
                },
                "Period": 60,
                "Stat": "Sum"
            },
            "Id": "m2",
            "ReturnData": "False"
        },
        {
            "MetricStat": {
                "Metric": {
                    "MetricName": "RequestsThrottled",
                    "Namespace": "MyService"
                },
                "Period": 60,
                "Stat": "Sum"
            },
            "Id": "m3",
            "ReturnData": "False"
        },
        {
            "MetricStat": {
                "Metric": {
                    "MetricName": "ConnectionAttempts",
                    "Namespace": "MyService"
                },
                "Period": 60,
                "Stat": "Sum"
            },
            "Id": "m4",
            "ReturnData": "False"
        },
        {
            "Id": "error_total",
            "Expression": "m1+m2+m3",
            "ReturnData": "False"
        },
        {
            "Id": "error_rate",
            "Expression": "(error_total/m4)*100",
            "ReturnData": "true",
            "Label": "Total Connection Error Rate"
        }
    ]
}

Anomaly Detection Model Alarm

The following example sets an alarm on an anomaly detection model. The Id of m1 is assigned to the CPUUtilization metric of an instance. t1 is the anomaly detection model function for that metric, and uses 3 standard deviations to set the width of the band. The setting of ThresholdMetricId is t1 and the ComparisonOperator is LessThanLowerOrGreaterThanUpperThreshold, specifying that the alarm goes to alarm state when the metric value is outside the anomaly model band in either direction for two consecutive evaluation periods.

Sample Request

{
    "AlarmActions": [
        "arn:aws:sns:us-west-1:123456789012:my_sns_topic",
        "arn:aws:sns:us-west-1:123456789012:my_other_sns_topic"
    ],
    "AlarmName": "MyAlarmName",
    "AlarmDescription": "This alarm uses an anomaly detection model",
    "Metrics": [
        {
            "Id": "m1",
            "ReturnData": true,
            "MetricStat": {
                "Metric": {
                    "MetricName": "CPUUtilization",
                    "Namespace": "AWS/EC2",
                    "Dimensions": [
                        {
                            "Name": "instanceId",
                            "Value": "i-1234567890abcdef0"
                        }
                    ]
                },
                "Stat": "Average",
                "Period": 60
            }
        },
        {
            "Id": "t1",
            "Expression": "ANOMALY_DETECTION_BAND(m1, 3)"
        }
    ],
    "EvaluationPeriods": 2,
    "ThresholdMetricId": "t1",
    "ComparisonOperator": "LessThanLowerOrGreaterThanUpperThreshold"
}

Metrics Insights query alarm

The following example sets an alarm on an Metrics Insights query.

Sample Request

{
    "AlarmActions": [
        "arn:aws:sns:us-west-1:123456789012:my_sns_topic",
        "arn:aws:sns:us-west-1:123456789012:my_other_sns_topic"
    ],
    "AlarmName": "MetricsInsightsAlarm",
    "AlarmDescription": "This alarm uses a Metrics Insights query",
    "Metrics": [
        {
            "Id": "m1",
            "Expression": "SELECT AVG(CPUUtilization) FROM SCHEMA("AWS/EC2", InstanceId)",
            "Period": 60,
            "Label": "Average CPUUtilization query"
        }
    ],
    "EvaluationPeriods": 1,
    "Threshold": 65,
    "ComparisonOperator": "GreaterThanThreshold"
}

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: