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Hi Adam,
we have a business constraint that a value should not drop below 0. The value is calculated on the fly based on a set of entries. We offer a JAX-RS endpoint to allow adding entries but if the account drops below 0. Imagine just a basic bank account where you have 50€ and you can book as long you have enough funds on your account.
Some clients started to replay their POST requests and dropped below 0€ because of race conditions,
because when the request was posted they had enough funds. How can you prevent that? Obviously, we told the clients to stop that, but we want to protect the business constraints on our side, too.
Love from Essen, DE