MQTT

RabbitMQ is a message broker that allows clients to connect over different open and standardized protocols such as AMQP, HTTP, STOMP, MQTT, MQTT over WebSockets and STOMP over WebSockets.

MQ Telemetry Transport is a publish-subscribe pattern-based "lightweight" messaging protocol. The protocol is often used in the IoT (Internet of Things) world of connected devices. It is designed for built-in systems, mobile phones, and other memory and bandwidth sensitive applications.

CloudAMQP does recommend the AMQP protocol in favor of the MQTT protocol.

MQTT provides an asynchronous communications protocol; the sender and receiver of the message do not need to interact with the message queue, the topic, at the same time. Messages placed onto the topic are stored until the recipient retrieves them or the messages time out. MQTT is for good use by bandwidth-sensitive applications.

MQTT protocol on RabbitMQ

The MQTT plugin is available on all plans.

The MQTT plugin needs to be enabled on dedicated plans. Activate the plugin from the Plugin page. The port used for MQTT is 1883 (8883 for TLS wrapped MQTT). Use the same default username and password as for AMQP. When signing in, add the vhost to the username. The vhost is the same as the username for shared plans:
vhost:username

QoS 1 is supported (if you are setting QoS 2, it will downgrade to QoS 1).

Learn more about MQTT for RabbitMQ in the official documentation: RabbitMQ MQTT Plugin

Language-specific documentation can be found here: Ruby, Python, NodeJS, Java, GO, .NET, NodeMCU (Lua), PHP.

Example when using mosquitto and TLS on shared instances:

//Subscribe
mosquitto_sub -h hostname -d -t topic -u my_vhost:my_username -P my_password -c -i test1 -q 1 --cafile /usr/local/etc/openssl/cert.pem -p 8883

//Publish
mosquitto_pub -h hostname -d -m message -t topic -u my_vhost:my_username -P password

If you have any questions, please feel free to contact support@cloudamqp.com for further assistance.