AWS::CloudWatch::LogAlarm

Creates or updates a log alarm. A log alarm evaluates the results of a CloudWatch Logs scheduled query against the configured threshold and comparison operator to determine its state.

When you create a log alarm, the operation creates a service-managed CloudWatch Logs scheduled query that runs the query string you provide on the schedule you configure. Each scheduled query execution returns one or more aggregated values determined by the AggregationExpression, and each aggregated value is compared against the alarm Threshold to determine the alarm state. The alarm uses M-out-of-N evaluation: if QueryResultsToAlarm out of the most recent QueryResultsToEvaluate query results breach the threshold, the alarm transitions to ALARM.

Log alarms support the alarm states (OK, ALARM, INSUFFICIENT_DATA). Configure transition actions using OKActions, AlarmActions, and InsufficientDataActions.

If you call this operation with the name of an existing log alarm, the operation replaces the previous configuration of that alarm.

Permissions

To create or update a log alarm, you must have the cloudwatch:PutLogAlarm permission. The IAM role specified in ScheduledQueryRoleARN must grant the CloudWatch Alarms service permission to execute scheduled queries on the specified log groups. If you set ActionLogLineCount, the role specified in ActionLogLineRoleArn must grant permission to retrieve log events for inclusion in alarm notifications.

Syntax

To declare this entity in your CloudFormation template, use the following syntax:

JSON

{
  "Type" : "AWS::CloudWatch::LogAlarm",
  "Properties" : {
      "ActionLogLineCount" : Integer,
      "ActionLogLineRoleArn" : String,
      "ActionsEnabled" : Boolean,
      "AlarmActions" : [ String, ... ],
      "AlarmDescription" : String,
      "AlarmName" : String,
      "ComparisonOperator" : String,
      "InsufficientDataActions" : [ String, ... ],
      "OKActions" : [ String, ... ],
      "QueryResultsToAlarm" : Integer,
      "QueryResultsToEvaluate" : Integer,
      "ScheduledQueryConfiguration" : ScheduledQueryConfiguration,
      "Tags" : [ Tag, ... ],
      "Threshold" : Number,
      "TreatMissingData" : String
    }
}

YAML

Type: AWS::CloudWatch::LogAlarm
Properties:
  ActionLogLineCount: Integer
  ActionLogLineRoleArn: String
  ActionsEnabled: Boolean
  AlarmActions: 
    - String
  AlarmDescription: String
  AlarmName: String
  ComparisonOperator: String
  InsufficientDataActions: 
    - String
  OKActions: 
    - String
  QueryResultsToAlarm: Integer
  QueryResultsToEvaluate: Integer
  ScheduledQueryConfiguration: 
    ScheduledQueryConfiguration
  Tags: 
    - Tag
  Threshold: Number
  TreatMissingData: String

Properties

ActionLogLineCount

The number of log lines from the most recent scheduled query execution to include in alarm action notifications. Valid range is 0 through 50. The default is 0, which means no log lines are included.

Required: No

Type: Integer

Minimum: 0

Maximum: 50

Update requires: No interruption

ActionLogLineRoleArn

The Amazon Resource Name (ARN) of an IAM role that CloudWatch assumes to retrieve log events for inclusion in alarm action notifications. Required when ActionLogLineCount is greater than 0.

Required: No

Type: String

Update requires: No interruption

ActionsEnabled

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

Required: No

Type: Boolean

Update requires: No interruption

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:

Amazon SNS actions:

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

Systems Manager actions:

arn:aws:ssm:region:account-id:opsitem:severity

Required: No

Type: Array of String

Update requires: No interruption

AlarmDescription

The description for the alarm.

Required: No

Type: String

Update requires: No interruption

AlarmName

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

Required: No

Type: String

Minimum: 1

Maximum: 255

Update requires: Replacement

ComparisonOperator

The arithmetic operation to use when comparing the aggregated query result and the threshold. The aggregated query result is used as the first operand. Valid values are GreaterThanThreshold, GreaterThanOrEqualToThreshold, LessThanThreshold, and LessThanOrEqualToThreshold.

Required: Yes

Type: String

Update requires: No interruption

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:

Amazon SNS actions:

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

Required: No

Type: Array of String

Update requires: No interruption

OKActions

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

Valid Values:

Amazon SNS actions:

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

Required: No

Type: Array of String

Update requires: No interruption

QueryResultsToAlarm

The number of query results, out of the most recent QueryResultsToEvaluate results, that must breach the threshold to trigger the alarm to transition to ALARM (the M in M-of-N evaluation). Must be less than or equal to QueryResultsToEvaluate.

Required: Yes

Type: Integer

Update requires: No interruption

QueryResultsToEvaluate

The number of most recent scheduled query results to evaluate against the threshold (the N in M-of-N evaluation). Valid range is 1 through 100.

Required: Yes

Type: Integer

Update requires: No interruption

ScheduledQueryConfiguration

The configuration of the underlying CloudWatch Logs scheduled query, including the query string, log groups, schedule, aggregation expression, and the ARN of the managed scheduled query.

Required: Yes

Type: ScheduledQueryConfiguration

Update requires: No interruption

Tags

A list of key-value pairs to associate with the alarm. You can use tags to categorize and manage your alarms.

Required: No

Type: Array of Tag

Maximum: 50

Update requires: No interruption

Threshold

The value to compare with the aggregated query result.

Required: Yes

Type: Number

Update requires: No interruption

TreatMissingData

Sets how this alarm is to handle missing data points. Valid values are breaching, notBreaching, ignore, and missing. If this parameter is omitted, the default behavior of missing is used.

Required: No

Type: String

Update requires: No interruption

Return values

Ref

Fn::GetAtt

Arn

Property description not available.