AWS Lambda: Identifying cold starts
Is there a clear way to identify "cold starts"? Either in runtime in the Lambda itself, or via the logs? I know that cold starts are characterized by longer runtimes, which I can actually see, but I'm looking for a clear cut way. I'm using Node.js if that matters.
Update: There are two good answers below, for two use cases: - Identifying the cold start as the lambda runs. - Identifying the cold start from the CloudWatch log.