JavaScript Cloud Native Development Cookbook

How it works...

This recipe builds on recipes that we have already covered. We submit an order domain object using database-first Event Sourcing, and we have a query function to retrieve the current status of the order. The listener function is the most interesting part of this recipe. It listens for the reservation-violation events and performs a compensating action. In this case, the compensation is simply to change the status to cancelled. Compensating actions can be arbitrarily complex and are specific to a given service. For example, a service may need to reverse a complex calculation, while accounting for intermediate changes and triggering cascading changes as well. The audit trail provided by Event Sourcing and a micro event store ...