MQTT-BROKER

MQTT pub/sub message routing server.

Definition

MQTT broker key features: Topic-based routing, QoS levels (0 At Most Once, 1 At Least Once, 2 Exactly Once), Retained messages, Last Will Testament, Persistent Sessions, Shared Subscriptions (MQTT v5), Authentication (PSK, TLS X.509, OAuth2), Authorization (per-topic ACLs), Clustering. Capacity: EMQX ~10M clustered connections, AWS IoT Core ~100M+. MQTT v5 adds Properties, Reason Codes, Topic Aliases for bandwidth reduction.

Origin

MQTT specification created IBM 1999 by Andy Stanford-Clark and Arlen Nipper ; standardised OASIS MQTT v3.1.1 2014 ; MQTT v5 published 2019 ; ISO/IEC 20922 published 2016.

Example in context

A smart city deploys HiveMQ Cloud MQTT v5 broker for 250000 sensors ; QoS 1 for metrics, persistent sessions for reconnections, $200/month for 100M messages.

Related terms

• MQTT Sparkplug B — IIoT payload profile.