Tuesday, February 8, 2011

Comment on: RESTful SOA or Domain-Driven Design - A Compromise?

I find this talk by Vaughn Vernon very encouraging and it fits nicely into what we are trying to achieve.
It is very clear and educational and should be made basic training at our site.

It actually fils a gap very nicely as to how our target architecture may be implemented, and more importanlty; why it should behave as as described. The Continual Aggregate Hub and restaurant is really a macro description of how such domain systems may cooperate in a pipeline, and how they can share a document (this is how we store Aggregates) storage.

In in the migrate to the cloud I am talking about ´Cooperating federated systems´; and this is exactly what I observe Vernon is talking about in his presentation. I especially like the Domain Event (page 19 and 34), it is the implementation of what I have called the ´Lifecyle´. Maybe lifecycle is not a good word, but it chosen to illustrate what drives behavior on the domain objects, between and within, these loosely coupled systems (they have separate bounded contexts).

The Domain Event Publisher (page 37) is the Process-state and handling of the CDH, and it is relaxed so that subscribing Modules may consume at a pace they wish. The Event logger is also an important aspect of it so that re-running event is possible. (illustrated nicely at page 39-).

We have very interesting performance results (over 50.000 aggregates pr second) from a Proof of Concept on Continual Aggregate Hub running it in a grid.

(BTW: The real essence is not RESTful or not. Other service implementations and protocols will also do)

1 comment:

  1. Thanks for your positive feedback. Glad you enjoyed the presentation and can benefit from the concepts. True, the DDD patterns can be applied outside a REST environment, and they often are.