Pros of EMQX

• Highly scalable, supporting millions of concurrent MQTT connections
• Rich features including rule engine, data bridging, and multi-protocol support
• Built-in clustering for high availability and fault tolerance

Cons of EMQX

• More complex setup and configuration compared to Mosquitto
• Higher resource requirements for running and maintaining
• Steeper learning curve for beginners

Code Comparison

EMQX (Erlang):

-module(emqx_broker).
-export([publish/1]).

publish(Message) ->
    emqx:publish(Message).

Mosquitto (C):

#include "mosquitto.h"

int publish_message(struct mosquitto *mosq, const char *topic, const char *payload) {
    return mosquitto_publish(mosq, NULL, topic, strlen(payload), payload, 0, false);
}

Key Differences

• EMQX is written in Erlang, while Mosquitto is written in C
• EMQX offers a more extensive feature set for enterprise-level deployments
• Mosquitto is lightweight and easier to set up for smaller projects
• EMQX provides built-in clustering, while Mosquitto requires additional configuration for clustering
• EMQX has a web-based dashboard for management, whereas Mosquitto relies on command-line tools

Both brokers are open-source and support the MQTT protocol, but they cater to different use cases and deployment scales.

Pros of VerneMQ

• Highly scalable and distributed architecture, suitable for large-scale deployments
• Built-in clustering capabilities for improved fault tolerance and load balancing
• Extensive plugin system for customization and integration with other services

Cons of VerneMQ

• Steeper learning curve and more complex configuration compared to Mosquitto
• Higher resource requirements, which may be overkill for smaller projects
• Less widespread adoption and community support than Mosquitto

Code Comparison

VerneMQ (Erlang):

vmq_server:start_listener(1883, [{max_connections, 100000},
                                 {nr_of_acceptors, 100},
                                 {mountpoint, ""}]).

Mosquitto (C):

mosquitto_new("client_id", true, NULL);
mosquitto_connect(mosq, "localhost", 1883, 60);
mosquitto_loop_start(mosq);

VerneMQ's code snippet demonstrates its focus on high-performance settings, while Mosquitto's code shows its simplicity in establishing a basic connection.

Both projects are open-source MQTT brokers, but they cater to different use cases. Mosquitto is lightweight and easy to set up, making it ideal for small to medium-sized projects and IoT applications. VerneMQ, on the other hand, is designed for large-scale, distributed systems that require high availability and scalability.

The choice between the two depends on the specific requirements of your project, such as expected load, scalability needs, and available resources for deployment and maintenance.

Pros of HiveMQ Community Edition

• Scalable architecture designed for enterprise-level deployments
• Built-in clustering support for high availability
• Extensive plugin system for customization and integration

Cons of HiveMQ Community Edition

• Higher resource requirements compared to Mosquitto
• Steeper learning curve for configuration and management
• Limited documentation for the community edition

Code Comparison

Mosquitto configuration example:

listener 1883
protocol mqtt
allow_anonymous true

HiveMQ Community Edition configuration example:

<hivemq>
    <listeners>
        <tcp-listener>
            <port>1883</port>
        </tcp-listener>
    </listeners>
    <anonymous-usage-statistics>
        <enabled>false</enabled>
    </anonymous-usage-statistics>
</hivemq>

Mosquitto is known for its simplicity and lightweight nature, making it ideal for small to medium-sized deployments. It uses a straightforward configuration file format and has a smaller memory footprint.

HiveMQ Community Edition, on the other hand, offers more advanced features suitable for large-scale, enterprise-level implementations. It uses XML-based configuration files, which provide more flexibility but can be more complex to manage.

Both projects are open-source MQTT brokers, but they cater to different use cases and deployment scales. The choice between them depends on the specific requirements of the project, such as scalability needs, resource constraints, and desired features.

Pros of RabbitMQ Server

• More feature-rich with advanced routing capabilities and multiple messaging protocols
• Better scalability and clustering support for high-availability setups
• Comprehensive management UI and monitoring tools

Cons of RabbitMQ Server

• Higher resource consumption and complexity compared to Mosquitto
• Steeper learning curve for configuration and management
• Less suitable for lightweight IoT applications

Code Comparison

Mosquitto (C):

mosquitto_publish(mosq, NULL, topic, strlen(message), message, 0, false);

RabbitMQ (Erlang):

basic_publish(Channel, <<"">>, RoutingKey, Payload, #'basic.properties'{})

Both examples show a basic message publish operation. Mosquitto's API is simpler and more straightforward, while RabbitMQ's offers more flexibility with routing and message properties.

Mosquitto is lightweight and ideal for MQTT-based IoT scenarios, while RabbitMQ is a more robust, feature-rich message broker suitable for complex enterprise messaging needs. The choice between them depends on specific project requirements, scalability needs, and the desired level of complexity in message routing and management.

Pros of ActiveMQ

• Supports multiple protocols (AMQP, MQTT, STOMP) in addition to its native protocol
• Offers advanced features like message persistence, clustering, and security
• Provides a web-based management console for easier monitoring and administration

Cons of ActiveMQ

• Higher resource consumption and complexity compared to Mosquitto
• Steeper learning curve and more challenging setup process
• May be overkill for simpler messaging scenarios or IoT applications

Code Comparison

Mosquitto (C):

mosquitto_publish(mosq, NULL, topic, strlen(message), message, 0, false);

ActiveMQ (Java):

MessageProducer producer = session.createProducer(destination);
TextMessage message = session.createTextMessage(text);
producer.send(message);

Summary

Mosquitto is a lightweight, MQTT-focused broker ideal for IoT and simple messaging scenarios. ActiveMQ is a more feature-rich, multi-protocol message broker suitable for complex enterprise messaging needs. While Mosquitto excels in simplicity and efficiency, ActiveMQ offers advanced features at the cost of increased complexity and resource usage.