Glossary · System coordination, integration and orchestration
Event broker
Also known as: message broker, event streaming platform
German: Event Broker
In software architecture, an event broker is middleware that receives events from producers and delivers them to interested consumers, typically through publish-subscribe topics, decoupling producers from consumers in time, location and number.
- System integration
In one sentence
An event broker receives events from producers and delivers them to subscribed consumers, decoupling them in time, location and number.
Example
Edge gateways publish machine states to topics on an MQTT broker; the MES, the energy dashboard and the maintenance system each subscribe to the topics they need.
How it applies
- Architecture: Event brokers support event-driven integration: producers don't need to know consumers, and new consumers can be added without changing producers. MQTT brokers and log-based streaming platforms are common examples.
- Engineering: Define topic structure, message schemas, delivery guarantees (at most once, at least once), retention and access rights. With at-least-once delivery, consumers must tolerate duplicates.
- Documentation: A topic catalog listing topics, payload schemas, producers, consumers and owners is essential. Document how the broker is secured and what happens to events when a consumer is offline.
Event broker vs. integration broker
An event broker distributes events with little processing. An Integration broker typically also transforms messages and orchestrates exchanges between applications. Many plant architectures combine an event broker for machine data with an integration broker for business messages.