I have the following Cloudwatch alarm set on my instances:
aws cloudwatch put-metric-alarm \
--alarm-name stop-when-idle \
--namespace AWS/EC2 \
--metric-name CPUUtilization \
--statistic Maximum \
--period 300 \
--evaluation-periods 3 \
--threshold 10 \
--comparison-operator LessThanThreshold \
--unit Percent \
--dimensions "Name=InstanceId,Value=$INSTANCE_ID" \
--alarm-actions arn:aws:automate:$AWS_REGION:ec2:stop
However, it recently failed to run; it triggered successfully, and two seconds later attempted to run the stop action, but it says:
Failed to execute action arn:aws:automate:us-east-1:ec2:stop. Received error: ""
Looking at the full details, I see:
{
"alarmName": "stop-when-idle",
"alarmType": "MetricAlarm",
"timestamp": "2023-03-16T07:01:07.187Z",
"historyItemType": "Action",
"historySummary": "Stop EC2 Instance 'i-REDACTED' failed",
"historyData": {
"actionState": "Failed",
"stateUpdateTimestamp": 1678950065929,
"notificationResource": "arn:aws:automate:us-east-1:ec2:stop",
"publishedMessage": null,
"error": null
}
}
With no error listed. What can I do to figure out why this didn't work?