HiveMQ

HiveMQ is a Java-based MQTT broker implementing the full MQTT 3.x and MQTT 5 specifications. The Community Edition provides a solid foundation for IoT pilots and embedded applications, while the Enterprise platform adds horizontal clustering, high availability, and dedicated support for large-scale deployments.

What it does

HiveMQ brokers messages between MQTT clients using a publish-subscribe pattern. It handles connection management, topic routing, QoS enforcement, and message persistence. The broker supports standard MQTT features including retained messages, last will and testament, and persistent sessions.

Key features

• Full MQTT 3.1, 3.1.1, and 5.0 protocol support
• WebSocket transport for browser-based clients
• TLS/SSL encryption and certificate-based authentication
• Plugin system for custom authentication and authorization
• Extension SDK for protocol adapters and custom logic
• Built-in metrics and monitoring hooks

Deployment options

HiveMQ Community Edition runs as a standalone Java application or Docker container. The Enterprise edition adds Kubernetes operators and cloud-managed deployment options. Minimum requirements are modest for CE (Java 11+, 512MB RAM), while Enterprise clusters scale to millions of concurrent connections.

Limitations

• Community Edition lacks built-in clustering; high availability requires Enterprise licensing
• Java runtime dependency adds memory overhead compared to native brokers like Mosquitto
• Enterprise features like the Control Center and professional support carry significant licensing costs
• Plugin development requires Java knowledge, limiting extensibility for teams without JVM expertise
• HiveMQ Edge (protocol gateway) is a separate product with its own deployment model