CloudWatch Alarm Actions Missing

What this rule checks

Detects CloudWatch Alarms without alarm actions or missing-data handling.

How to fix it

1. 1Add AlarmActions (SNS, Lambda, SSM) for state-change notifications
2. 2Set TreatMissingData to define behaviour for missing data points

import { Duration } from 'aws-cdk-lib';
import { Alarm, Metric } from 'aws-cdk-lib/aws-cloudwatch';

new Alarm(this, 'QueueDepthAlarm', {
  metric: new Metric({
    namespace: 'AWS/SQS',
    metricName: 'ApproximateNumberOfMessagesVisible',
    period: Duration.minutes(5),
  }),
  threshold: 100,
  evaluationPeriods: 1,
});

import { Duration } from 'aws-cdk-lib';
import { Alarm, Metric, TreatMissingData } from 'aws-cdk-lib/aws-cloudwatch';
import { SnsAction } from 'aws-cdk-lib/aws-cloudwatch-actions';
import { Topic } from 'aws-cdk-lib/aws-sns';

const topic = new Topic(this, 'AlarmTopic');
const alarm = new Alarm(this, 'QueueDepthAlarm', {
  metric: new Metric({
    namespace: 'AWS/SQS',
    metricName: 'ApproximateNumberOfMessagesVisible',
    period: Duration.minutes(5),
  }),
  threshold: 100,
  evaluationPeriods: 1,
  treatMissingData: TreatMissingData.NOT_BREACHING,
});
alarm.addAlarmAction(new SnsAction(topic));

CDK Insights pinpoints the exact file and line in your CDK source for every finding, so you can jump straight to the fix.

Affected resource types

Intentional? Suppress this finding

Sometimes a flag is deliberate — a genuinely public endpoint, say. You can dismiss cloudwatch-alarm-actions-missing and the reason is kept in the report, not silently hidden.

In .cdk-insights.json:

{
  "ignoreRules": [
    { "id": "cloudwatch-alarm-actions-missing", "reason": "Why this is intentional" }
  ]
}

Or inline in your CDK code:

Validations.of(scope).acknowledge({
  id: 'cdk-insights::cloudwatch-alarm-actions-missing',
  reason: 'Why this is intentional',
});

Use the rule ID cloudwatch-alarm-actions-missing shown above — not the CDK-* ID from SARIF / GitHub code scanning. To dismiss every finding on one construct instead, use ignorePaths. Suppression docs →

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