MQTT 3.1.1

MQTT 3.1.1 implementation in MAPS Messaging.

Features

• QoS 0, 1, 2
• Retained messages
• Last Will and Testament (LWT)
• Clean / Persistent sessions

Quick Start

protocols:
  mqtt:
    version: "3.1.1"
    port: 1883

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Configuration (3.1.1)

Fields below map to the common MQTT configuration (MqttConfigDTO). Properties specific to MQTT 5 (e.g., topic aliases, receive maximum) do not apply to 3.1.1.

Field	Type	Default	Description
maximumSessionExpiry	long (s)	86400	Upper bound for session expiry; 3.1.1 uses clean session semantics, but MAPS enforces an internal cap for persistence windows.
maximumBufferSize	long (bytes)	10485760	Max per-connection buffer before backpressure.
strictClientId	boolean	false	Enforce spec-compliant client IDs (reject empty/invalid).

Example with guards

protocols:
  mqtt:
    version: "3.1.1"
    port: 1883
    maximumBufferSize: 1048576       # 1 MiB
    maximumSessionExpiry: 86400
    strictClientId: true