Introduction

EMQX (opens new window) is an Open-source MQTT (opens new window) broker with a high-performance real-time message processing engine, powering event streaming for IoT devices at massive scale.

As the most scalable MQTT broker, EMQX can help you connect any device, at any scale. Move and process your IoT data anywhere.

Benefits

• Massive Scale (opens new window): Scale to 100 million concurrent MQTT connections with a single EMQX 5.0 cluster.
• High Performance: Move and process millions of MQTT messages per second in a single broker.
• Low Latency: Guarantee sub-millisecond latency in message delivery with the soft real-time runtime.
• Fully MQTT 5.0 (opens new window): 100% compliant with MQTT 5.0 and 3.x standard for better scalability, security, and reliability.
• High Availability: Achieve high availability and horizontal scalability through a masterless distributed architecture.
• Cloud-Native & K8s (opens new window): Easy to deploy on-premises or in public clouds with Kubernetes Operator and Terraform.

Features List

Below is a brief/incomplete feature list, highlighting the features EMQX provides.

Connectivity

• Full MQTT v3.1, v3.1.1 and v5.0 protocol specification support
  • QoS 0, QoS 1, QoS 2 message support
  • Persistent conversation and offline message support
  • Retained message support
  • Last Will message support
  • Shared subscription support
  • $SYS/ system topic support
• MQTT supports 4 transport protocols
  • TCP
  • TLS
  • WebSocket
  • QUIC (Experimental)
• HTTP message publishing interface support
• Gateways
  • CoAP
  • LwM2M
  • MQTT-SN
  • Stomp
  • GB/T 32960 (Enterprise edition)
  • JT/T 808 (Enterprise edition)

Add more features to MQTT:

• Delayed Publish
• Auto subscription
• Topic rewrite

Security

• Authentication based on username/password supported using built-in database, Redis, MySQL, PostgreSQL, and MongoDB as data sources, and HTTP Server to provide authentication services
• Authentication based JWT supported using JWKs
• Enhanced Authentication for MQTT 5.0
• PSK authentication
• Access control (Authorization) based on Client ID, IP address, and username supported using built-in database, Redis, MySQL, PostgreSQL, and MongoDB as data sources, and HTTP Server to provide authorization services
• Client blacklist

Scalability

• Multi-server node cluster (Cluster)
• Support manual cluster and auto cluster discovery(dns、etcd、k8s), see sreate clster
• Multi-server node bridge (Bridge)

Data Integration

• SQL syntax data integrations to extract, filter, enrich, and transform MQTT messages or internal events to formats expected by users and send them to external data platforms
• Supports data bridging with other brokers or IoT platforms using MQTT(such as EMQX Cloud (opens new window), AWS IoT Core, Azure IoT Hub)
• Supports integration with other apps using WebHook

Reliability

• Overload protection
• Message rate limit
• Connection rate limit

Observability

• Client online status query
• Cluster status and metrics query
• Integration with Prometheus/StatsD
• Automatic network partition healing
• Online log based tracing]
• Erlang runtime tracing tools

Extensibility

• Plugins
• Hooks
• gRPC hook extension
• gRPC protocol extension