Too Long; Didn't Read
When a Lambda function invocation crashes due to an uncaught application error, for example, AWS may automatically retry the same request. This auto-retry happens when the function is invoked: Asynchronously by any type of requester by an event source mapping, such as data streams from DynamoDB or Kinesis. In some cases, it’s just pointless to retry if the first request failed, it has zero chance of succeeding in subsequent attempts. Retrying could also lead to unwanted side-effects if our code is not idempotent.