MQTT - Generic

4 min

Overview

The MQTT - Generic integration enables Litmus Edge (LE) to connect to an MQTT broker.

Supported versions

Compatible with MQTT Protocol version 3.1.0 and MQTT Protocol version 3.1.1

Supported communication

Outbound (Publish data from Edge to MQTT Broker) - Yes

Inbound (Subscribe data from MQTT Broker to Edge) - Yes

Configurations

Field	Details	Required
Name	Name of the connector instance.	Yes
Connection Type	Choose tcp for an unencrypted connection or ssl for a TLS-encrypted connection to the MQTT broker.	Yes
Hostname	DNS name of MQTT host.	Yes
Port	Port of MQTT host.	No
CA Certificate	CA certificate used to verify the server, in PEM format. Can also be installed in the system-wide certificate store.	Yes
Certificate	Client certificate for mutual TLS authentication with the MQTT broker. Paste the PEM-encoded certificate here.	Yes
Private key	Private key corresponding to the client certificate. Must match the Certificate field above.	Yes
Client ID	Client ID is required by MQTT server.	No
Username	Username for authenticating with the MQTT broker.	No
Password	Password for authenticating with the MQTT broker.	No
QoS	Quality of Service delivery guarantee: 0 = at most once, 1 = at least once, 2 = exactly once.	No
Parallel Publish Count	Number of messages published in parallel. Higher values increase throughput and resource usage.	Yes
Integration Topic	MQTT topic path where data is published.	Yes
Ping Timeout (seconds)	The time a client waits for a ping response from the broker after sending a PINGREQ message.	No
LWT topic	MQTT topic the broker publishes the Last Will message to if this client disconnects unexpectedly.	No
LWT payload	Message content published to the LWT topic on unexpected disconnection. Typically a status or alert string.	No
LWT payload type	Encoding of the LWT payload: string for plain text, base64 for binary data.	No
LWT QoS	QoS level for the Last Will message: 0 = at most once, 1 = at least once, 2 = exactly once.	No
LWT retained	When enabled, the broker retains the Last Will message and immediately delivers it to any new subscriber on that topic.	No
Throttling limit	Set a limit on the number of outbound messages per second. If sending data to a server that has restrictions on the rate of incoming messages, this ensures that no messages are lost.	No

Persistent storage configurations

Field	Details	Required
Persistent storage	If enabled, messages in the outbound queue are stored on disk. If there are interruptions in connection or power loss, messages are retained and eventually sent when the connection is restored.	No
Persistent storage size limit	Set the size limit for storing persisted data in GB.	No
Queue mode	Select the sequence of data transfer: FIFO or LIFO. Selecting FIFO (First In First Out) sends the earliest message first. Selecting LIFO (Last In First Out) sends the latest message first.	No