An introduction to event-driven architecture
Event-driven architecture (EDA) is a paradigm that revolves around consuming streams of events, or data in motion, instead of consuming static states.
What I define by a static state is the data stored in a relational database table or other types of data stores, like a NoSQL documents store. That data is dormant in a central location and waiting for actors to consume and mutate it. It is stale between every mutation and the data (a record, for example) represents a finite state.
On the other hand, data in motion is the opposite: you consume the ordered events and determine the change in state that each event brings.
What is an event? People often interchange the words event, message, and command. Let’s try to clarify this:
- A message is a piece of data that represents something.
- A message can be an object, a JSON string, bytes, or anything else your system can interpret.
- An event is a message that...
