The solution I went with was to add a System aggregate root that could maintain a list of the current Facility names. When creating a new Facility, I use the System aggregate (only one System as a global object / singleton) as a factory for it. If the given facility name already exists, then it … Read more
When integrating BCs, you have a few options. The reason that calling out to an external BC is discouraged is because it requires for both BCs to be operational at the same time. However, this is often quite acceptable and is simpler than the alternative. An alternative is to have the Game BC subscribe to … Read more
I think what you really meant to ask was regarding ‘Multiple Aggregates in one transaction‘. I don’t believe there is anything wrong with using multiple repositories to fetch data in a transaction. Often during a transaction an aggregate will need information from other aggregates in order to make a decision on whether to, or how … Read more
I wouldn’t say that it’s an anti-pattern since an anti-pattern is supposed to be a pattern in the first place (a recognizable, widespread way of doing things) and I don’t know of any “Repository-in-the-Domain-object” pattern. However, it’s certainly bad practice IMO because your BankAccount domain object mixes 3 responsibilities : Its natural and legitimate responsibility … Read more
I am one of the original authors of Kafka. Kafka will work very well as a log for event sourcing. It is fault-tolerant, scales to enormous data sizes, and has a built in partitioning model. We use it for several use cases of this form at LinkedIn. For example our open source stream processing system, … Read more