How to Fix: AWS cloudwatch failed to execute action. Error: ""

The error 'Failed to execute action arn:$policy_arn Received error: ''' occurs when AWS CloudWatch is unable to trigger an Amazon ECS (Fargate) autoscaling policy due to a missing or invalid IAM policy. This issue affects users who have set up cloudwatch alarms to scale their ECS clusters based on specific metrics, resulting in the inability to execute actions and receive notifications.

This error can be frustrating because it prevents users from receiving alerts and taking corrective action when their ECS cluster is experiencing issues. However, by following the steps outlined below, you should be able to resolve this issue and ensure that your cloudwatch alarms are triggering correctly.

💡 Why You Are Getting This Error

• The primary reason for this error is a missing or invalid IAM policy attached to the CloudWatch alarm. This can occur when the policy is not properly configured or if there are issues with the ARN (Amazon Resource Name) of the policy.
• Alternatively, the issue might be due to the AWS account having insufficient permissions or the CloudWatch logs not being able to read the IAM policy.

🔧 Proven Troubleshooting Steps

🎯 Final Words

By following these steps, you should be able to resolve the 'Failed to execute action arn:$policy_arn Received error: ''' issue and ensure that your cloudwatch alarms are triggering correctly. If you continue to experience issues, it may be helpful to consult with an AWS support specialist or seek additional assistance from a qualified IT professional.