Architecture, distribution and integration
Event distribution / streaming integration
Producers, topics and consumers of an event stream: who publishes what, who subscribes, and the contracts between them.
ddn@1New DDN source
Why use it?
Streaming systems fail on contracts, not on brokers; the diagram is where the contract gets reviewed.
When it helps
Designing or auditing event-driven integration.
How to read it
- Topics are the joints: everything else attaches to them.
- Consumers read at their own pace — the diagram shows subscriptions, not delivery guarantees.
What you need
- The event types
- Producers and consumers per topic
- Schema/contract owners
Things to check
- Do not draw point-to-point links around the broker — it hides the coupling the topics create.
- Do not leave the schema owner off a topic.
Scope of this diagram
Integration documentation; no throughput, ordering or replay semantics are modeled.
Work with the converted example
- Open the viewer and select
diagram. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.