The Outbox Pattern
Today I learned about the Outbox Pattern. The Outbox Pattern solves a common problem. Consider a system that charges a payment, processes an order, and then sends an email. The payment, order-processing, and email-sending all happen in a database transaction— if any of them fails, we roll back. A question: when the payment and order succeed, do we wait for the email to send before deciding that the transaction succeeded? What it the email-sending fails; do we roll back the payment and order? ...