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What is a Message Broker?

A message broker is a type of software that allows applications, systems, and services to communicate with each other. Also known as message queue (MQ) software, message brokers facilitate communication between various components and distributed systems, serving as an intermediary, ensuring messages are delivered from publishers to the appropriate subscribers.

Built by the original creators of Apache Kafka, Confluent powers scalable, real-time data integration, event-driven communication, stream processing, and analytics across 120+ apps, systems, and sources.

How Message Brokers Work

In the fast-changing world of enterprise IT systems, clear and direct communication between different components is critical. This is where message brokers come in, serving as the backbone that makes this communication smooth and efficient in a pub/sub (publisher-subscriber) messaging system.

A message broker is a server software that facilitates communication between different, often distributed systems, serving as an intermediary, routing messages, and ensuring that they are delivered from publishers to the appropriate subscribers. This communication method is fundamental in building scalable and adaptable enterprise messaging systems. Some well-known message brokers are RabbitMQ, ActiveMQ, HiveMQ, IBM MQ and Google Pub/Sub.

Message Broker Image

A well-designed pub/sub messaging system with a message broker operates following the event-driven architecture paradigm. Here's a closer look at how the elements come together:

  1. Event Generation: Events are generated when a change occurs in a system. It triggers the publishers to send a message to the message broker.
  2. Message Channeling or Routing: The message broker receives the messages and categorizes them based on topics or queues.
  3. Event Consumption: Subscribers that have subscribed to those topics or queues are notified and receive the messages.

Topics and queues are central elements in messaging architectures. Topics are used to implement 1:n and n:m communication patterns (multiple subscribers can receive the same message), while queues are best suited for 1:1 or n:1 communication.

The above building blocks allow developers to build event-driven systems that have the ability to react to events as they happen in real-time, allowing for fast insights and responses. Other, not event-driven paradigms that event-driven systems are contrasted with are request-response and batch processing systems.

Common Messaging Use Cases & Examples

Message brokers are widely used in enterprise back-end applications. Here are a few examples and use cases.

Real-Time Analytics and Monitoring

Financial trading platforms use message brokers to analyze market data in real-time, helping to make instantaneous trading decisions.

Supply Chain and Logistics

Shipping companies often use message brokers to track packages in real-time, coordinating between various systems for smooth logistics operations.

Social Media Notifications

Social media applications employ message brokers to manage the distribution of notifications and messages between users effectively.

Telecommunications Networks

Telecom companies use message brokers to handle SMS and call data records, facilitating billing and network management.

Smart Home Systems

Home automation platforms use message brokers to synchronize the functioning of various devices like lights, thermostats, and security cameras.

IoT Device Communication

Example: Smart city implementations use message brokers to facilitate communication between various IoT devices, collecting data and triggering actions based on predefined conditions.

Multi-Player Games

Example: Online multiplayer games like Fortnite use message brokers to manage real-time communications and game state synchronization between players.

These are just a few examples where message brokers play a crucial role, aiding in the efficient and reliable routing of data across various components and helping to scale and adapt to changing demands in (near) real-time.

Why Apache Kafka vs Traditional Messaging

While traditional message brokers were revolutionary when they debuted decades ago, today, they have numerous shortcomings. Apache Kafka was designed to address these issues. Here are some of the main benefits Kafka brings:

See also: Kafka vs Other Messaging Systems

Data Persistence

Most message brokers do not offer data persistence, meaning data is lost if not consumed promptly. Kafka, on the other hand, was designed with persistence in mind; it allows for configurable data retention, enabling a more reliable data storage and retrieval process.


Kafka has a distributed architecture that helps in horizontal scaling, a feature not found or limited in many traditional message brokers.

Fault Tolerance and Reliability

Kafka provides strong durability and fault tolerance features, making it more reliable for mission critical production systems compared to other brokers that might have single points of failure.

Stream Processing

Kafka was designed with stream processing in mind. It also integrates well with stream processing systems, which is not a characteristic of many message brokers. This capability facilitates real-time data processing and analytics.

Batch and Real-Time Processing

Kafka is adept at handling both batch and real-time data processing efficiently, whereas most message brokers don’t support batch processing use cases.

Security Features

Kafka offers robust security features including ACL-based security and SSL/TLS support.

Built-in Monitoring and Metrics

Kafka comes with built-in tools for monitoring and metrics, which can provide detailed insights into system performance and help in troubleshooting, a feature not as developed in many other message brokers.

Large Community and Ecosystem

Kafka has a large community and ecosystem with a rich set of APIs and connectors, easily surpassing other message brokers in this regard.

Real-Time Data Streaming With Confluent

When considering deploying Kafka in your enterprise, Confluent is a logical choice. Confluent provides a rich ecosystem of pre-built connectors, allowing you to consume data from and produce data to a wealth of back-end systems. You can process your events in real time and process and transform them as needed.

Confluent also offers a fully managed cloud service for Apache Kafka with pre-built connectors, automatic cluster scaling, security, and governance, allowing you to focus on your business with zero ops burden.