Apache ActiveMQ Artemis has a powerful & flexible core which provides a foundation upon which other protocols can be implemented. Each protocol implementation translates the ideas of its specific protocol onto this core.

The broker ships with a client implementation which interacts directly with this core. It uses what’s called the “core” API, and it communicates over the network using the “core” protocol.

1. Supported Protocols

The broker has a pluggable protocol architecture. Protocol plugins come in the form of protocol modules. Each protocol module is included on the broker’s class path and loaded by the broker at boot time. The broker ships with 5 protocol modules out of the box.

1.1. AMQP

AMQP is a specification for interoperable messaging. It also defines a wire format, so any AMQP client can work with any messaging system that supports AMQP. AMQP clients are available in many different programming languages.

Apache ActiveMQ Artemis implements the AMQP 1.0 specification. Any client that supports the 1.0 specification will be able to interact with Apache ActiveMQ Artemis.

Please see AMQP for more details.

1.2. MQTT

MQTT is a lightweight connectivity protocol. It is designed to run in environments where device and networks are constrained. Any client that supports the 3.1, 3.1.1, or 5 specification will be able to interact with Apache ActiveMQ Artemis.

Please see MQTT for more details.

1.3. STOMP

Stomp is a very simple text protocol for interoperating with messaging systems. It defines a wire format, so theoretically any Stomp client can work with any messaging system that supports Stomp. Stomp clients are available in many different programming languages. Any client that supports the 1.0, 1.1, or 1.2 specification will be able to interact with Apache ActiveMQ Artemis.

Please see Stomp for more details.

1.4. OpenWire

ActiveMQ Classic defines its own wire protocol: OpenWire. In order to support ActiveMQ “Classic” clients, Apache ActiveMQ Artemis supports OpenWire. Any ActiveMQ 5.12.x or higher can be used with Apache ActiveMQ Artemis.

Please see OpenWire for more details.

1.5. Core

ActiveMQ Classic defines its own wire protocol: OpenWire. In order to support ActiveMQ “Classic” clients, Apache ActiveMQ Artemis supports OpenWire. Any ActiveMQ 5.12.x or higher can be used with Apache ActiveMQ Artemis.

Please see Core for more details.

1.5.1. APIs and Other Interfaces

Although JMS and Jakarta Messaging are standardized APIs, they do not define a network protocol. The ActiveMQ Artemis JMS & Jakarta Messaging clients are implemented on top of the core protocol. We also provide a client-side JNDI implementation.

2. Configuring Acceptors

In order to make use of a particular protocol, a transport must be configured with the desired protocol enabled. There is a whole section on configuring transports that can be found here.

The default configuration shipped with the ActiveMQ Artemis distribution comes with a number of acceptors already defined, one for each of the above protocols plus a generic acceptor that supports all protocols. To enable protocols on a particular acceptor simply add the protocols url parameter to the acceptor url where the value is one or more protocols (separated by commas). If the protocols parameter is omitted from the url all protocols are enabled.

• The following example enables only MQTT on port 1883

  <acceptors>
     <acceptor>tcp://localhost:1883?protocols=MQTT</acceptor>
  </acceptors>

• The following example enables MQTT and AMQP on port 5672

  <acceptors>
     <acceptor>tcp://localhost:5672?protocols=MQTT,AMQP</acceptor>
  </acceptors>

• The following example enables all protocols on 61616:

  <acceptors>
     <acceptor>tcp://localhost:61616</acceptor>
  </acceptors>

Here are the supported protocols and their corresponding value used in the protocols url parameter.