申倬豪

AWS lambda requires that users should write [idempotent functions](https://aws.amazon.com/premiumsupport/knowledge-center/lambda-function-idempotent/). However, some functions in `aws-node-mongodb-atlas` do not ensure idempotence. For example, [`performQuery()`](https://github.com/serverless/examples/blob/72b9dbd10b80875969e2a015a8743324379ab92c/aws-node-mongodb-atlas/handler.js#L69) may insert more than one pet into the DynamoDB...

Bug : create_order is not idempotent

1

AWS uses retry to perform fault tolerance. To ensure correctness under retry, functions should be idempotent (AWS lambda requires that users should write [idempotent functions](https://aws.amazon.com/premiumsupport/knowledge-center/lambda-function-idempotent/). However, the function [`create_order`](https://github.com/aws-samples/aws-serverless-ecommerce-platform/blob/f504690fbbb9ff0335723bdc231bca97fb1a5db2/orders/src/create_order/main.py#L273-L284) is...