AWS CloudFormation: What is causing resources creation to be cancelled and how to debug?


I have no idea how to debug this cloudformation template from

I do not think this is datomic related, I think it’s something wrong with the cf template (since it is 2 years old now).

I follow the directions and everything goes smoothly, but when I check the cloudformation it results in failing with the following in the events, but doesn’t offer any helpful reasons as to why it failed. How do I get more information in CF so it will let me find out what’s wrong with my template?


I know nothing about Datomic, but the error in the event log posted is the following:

The other errors are Resource creation cancelled which are triggered after the initial error is raised and the automatic rollback of all updated/updating resources is initiated.

Beyond knowing that the A separate request to update this alarm is in progress error was raised on your DatomicMemIndexMB resource of type AWS::CloudWatch::Alarm, there is no more information available from CloudFormation. The implementation of the AWS::CloudWatch::Alarm resource is proprietary to AWS, so you can’t determine what this error exactly means in any further detail. However, if there’s something obvious such as an existing CloudWatch alarm already named DatomicMemIndexMB or if you’re trying to create/update two CloudFormation stacks at the same time, that’s probably the cause of this specific error.

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