Event Types By David Boyne
Event Types By David Boyne
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When building EDA applications, it’s important to know the different types of events you can publish, each has their own trade-offs.
Notification Events
- Minimal information
- Less risk of data being out of sync
- Consumers often need to fetch data
- Increases architecture coupling (callback for info)
- Producer/Consumer contracts kept minimum
- Lower risk of breaking contracts
Event-Carried State Transfer
- Enriched events (stateful)
- Higher risk of data being out of sync
- Consumers have the data
- Decreases architecture coupling
- Producer/consumer contracts more coupled
- Higher risks of breaking contracts
Delta events
- Stores difference between old/new
- Examples seen in change data capture events
- Can reduce complex in consumers needing to figure out what has changed
Domain Events
- Events that raised in the same bounded context
- Some folks reference these as internal events raised in bounded context
- Some folks reference these as business “important” events.
- People also refer to “integration” events. These are events used for integrations.
Extra Resources
- Best practices to design your events in event-driven applications - A talk I gave in 2022 around event design and trade-offs to consider.
- What do you mean by “Event Driven?” - Martin Fowler dives into event-driven architecture and talks about the different types of events
- The Event-Carried State Transfer Pattern - A great blog post on what ESCT is
- The event notification pattern - A great blog post on what notification events are
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Want to work together?
If you're interested in collaborating, I offer consulting, training, and workshops. I can support you throughout your event-driven architecture journey, from design to implementation. Feel free to reach out to discuss how we can work together, or explore my services on EventCatalog.
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