messagingbroker

A messaging broker is a software component that mediates the exchange of messages between producers and consumers. It decouples senders and receivers, enabling asynchronous communication, load leveling, and resilience.

It typically hosts message stores (queues and topics) and provides routing, persistence, delivery guarantees, and protocol translation. Producers publish messages to the broker, which stores them and forwards them to one or more consumers according to configured routing rules. Consumers establish subscriptions and receive messages, possibly in order and with durable delivery. Brokers support multiple messaging models, most commonly point-to-point (queues) and publish-subscribe (topics). Routing can be based on queues, topics, routing keys, or content filtering, and messages may be transformed or enriched by the broker.

Key features include durability, at-least-once or exactly-once delivery, acknowledgments, transactions, security (authentication, authorization, encryption), and high availability through clustering or replication. Brokers often support multiple protocols (for example AMQP, MQTT, STOMP, JMS) and can integrate with external systems via bridges or adapters.

Common use cases are decoupled microservices, background task processing, event-driven architectures, enterprise integration, and data pipelines for streaming or ETL. Operational considerations include monitoring, scaling, message retention, and failure recovery.

Examples of popular messaging brokers include RabbitMQ, Apache ActiveMQ, IBM MQ, and Apache Kafka (as a distributed log-based system). See also message queue, publish-subscribe pattern, event bus.