Event-Driven Architecture (2 of 3) – Broker Topology

• Useful when you don’t need orchestration of events
• The events are distributed across components (broadcasting)
• It has four main components:
• Initiating event: The event that starts the flow sent to the broker.
• Event broker: Processes the event and announces it to the system.
• Event Processor: Accepts events from the broker and sends the result as an event.
• Processing event: An event sent to the broker or reaches the final interested party.
• The event processor should always advertise its result.
• Pros: responsiveness, scalability, performance, decoupled event processors, fault tolerance
• Cons: workflow control, recoverability, a restart of transactions, error handling, possible data inconsistency
• Products used: RabbitMQ, ActiveMQ, HornetQ, Kafka, etc.)