Open source message broker
RabbitMQ is an open-source message-broker software (sometimes called message-oriented middleware) that originally implemented the Advanced Message Queuing Protocol (AMQP) and has since been extended with a plug-in architecture to support Streaming Text Oriented Messaging Protocol (STOMP), MQ Telemetry Transport (MQTT), and other protocols.
Written in Erlang, the RabbitMQ server is built on the Open Telecom Platform framework for clustering and failover. Client libraries to interface with the broker are available for all major programming languages. The source code is released under the Mozilla Public License.
Since November 2020, there are commercial offerings available of RabbitMQ, for support and enterprise features: "VMware RabbitMQ OVA", "VMware RabbitMQ" and "VMware RabbitMQ for Kubernetes" (different feature levels) Open-Source RabbitMQ is also packaged by Bitnami and commercially for VMware's Tanzu Application Service.
History.
Originally developed by Rabbit Technologies Ltd. which started as a joint venture between LShift and CohesiveFT in 2007, RabbitMQ was acquired in April 2010 by SpringSource, a division of VMware. The project became part of Pivotal Software in May 2013. Which then got acquired back by VMWare in December 2019.
The project consists of:
Examples.
This section gives sample programs written in Python (using the "pika" package) for sending and receiving messages using a queue.
Sending.
The following code fragment establishes a connection, makes sure the recipient queue exists, then sends a message and finally closes the connection.
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters(host="localhost"))
channel = connection.channel()
channel.queue_declare(queue="hello")
channel.basic_publish(exchange="", routing_key="hello", body="Hello World!")
print(" [x] Sent 'Hello World!'")
connection.close()
Receiving.
Similarly, the following program receives messages from the queue and prints them on the screen:
import pika
def callback(ch, method, properties, body):
 print(" [x] Received %r" % body)
connection = pika.BlockingConnection(pika.ConnectionParameters(host="localhost"))
channel = connection.channel()
channel.queue_declare(queue="hello")
print(" [*] Waiting for messages. To exit press Ctrl+C")
channel.basic_consume(queue="hello", on_message_callback=callback)
channel.start_consuming()
References.
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