https://aws.amazon.com/blogs/mt/how-to-enable-amazon-cloudwatch-alarms-to-send-repeated-notifications/
1️⃣
CloudWatch alarm is triggered and goes into the ALARM state.2️⃣
CloudWatch alarm sends the first alarm notification to the associated SNS alarm actions.3️⃣
CloudWatch Alarms service sends an alarm state change event which triggers the EventBridge rule.4️⃣
With a match event, the EventBridge rule invokes the Step Function target.5️⃣
Once the Step Function starts execution, it first enters a Wait state.6️⃣
The Step Function enters the Lambda Invocation task. The Lambda invocation task:▫️
Checks if the alarm has the specific tag key and value (e.g., RepeatedAlarm:true). If not, the function exits▫️
Checks the alarm’s current state by performing a DescribeAlarms API with the alarm name.▫️
Publishes the existing alarm’s status returned from the DescribeAlarms API call to all the SNS topics subscribed on the alarm▫️
Returns the alarm’s current state together with the original received event back to the Step Function.7️⃣
The Choice state checks the alarm state returned by the Lambda function and directs the workflow to go back to the Wait state if the alarm state is ‘ALARM’ otherwise it ends the step function’s execution.8️⃣
The repeated notification for an alarm within the workflow above stops when:▫️
The alarm transitions to a non-ALARM state.▫️
The alarm is deleted.▫️
A specific tag is removed from the alarm.#CloudWatch
