Java Message Broker

The most popular open source messaging and integration patterns server from the Apache Software Foundation, providing enterprise-class messaging capabilities with full Java Message Service compliance alongside support for multiple wire protocols and cross-language clients. The broker supports flexible deployment configurations including standalone, network of brokers with store-and-forward routing, master-slave replication for high availability, and shared storage failover. Protocol support includes OpenWire for native Java and C++ clients with high-performance serialization, AMQP 1.0 for interoperability across Python, Ruby, .NET, and JavaScript, STOMP for text-based messaging with WebSocket support for browsers, and MQTT for lightweight IoT connectivity. Message persistence options include KahaDB, a file-based append-only store optimized for fast recovery, JDBC persistence for database-backed storage, and LevelDB for memory-mapped storage. Transaction support includes local and XA transactions for distributed coordination. Destination features include queues for point-to-point messaging, topics for publish-subscribe, durable subscribers, composite destinations, virtual topics, and wildcard destination matching. The web console provides a browser-based interface for monitoring queue depths, browsing messages, and viewing statistics. Advanced features include message groups for ordered processing, scheduled delivery for future-dated messages, and dead letter strategies.