A message broker (also known as an integration broker or interface engine) is an intermediary computer program module that translates a message from the formal messaging protocol of the sender to the formal messaging protocol of the receiver. Message brokers are elements in telecommunication or computer networks where software applications communicate by exchanging formally-defined messages. Message brokers are a building block of

message-oriented middleware Message-oriented middleware (MOM) is software or hardware infrastructure supporting sending and receiving messages between distributed systems. MOM allows application modules to be distributed over heterogeneous platforms and reduces the comple ...

(MOM) but are typically not a replacement for traditional middleware like MOM and

remote procedure call In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure ( subroutine) to execute in a different address space (commonly on another computer on a shared network), which is coded as if it were a normal ...

(RPC).

Overview

A message broker is an

architectural pattern An architectural pattern is a general, reusable solution to a commonly occurring problem in software architecture within a given context. The architectural patterns address various issues in software engineering, such as computer hardware perfor ...

for message validation, transformation, and routing. It mediates communication among applications, minimizing the mutual awareness that applications should have of each other in order to be able to exchange messages, effectively implementing decoupling.

Purpose

The primary purpose of a broker is to take incoming messages from applications and perform some action on them. Message brokers can decouple end-points, meet specific non-functional requirements, and facilitate reuse of intermediary functions. For example, a message broker may be used to manage a workload queue or

message queue In computer science, message queues and mailboxes are software-engineering components typically used for inter-process communication (IPC), or for inter- thread communication within the same process. They use a queue for messaging – the ...

for multiple receivers, providing reliable storage, guaranteed message delivery and perhaps transaction management.

Life cycle

The following represent other examples of actions that might be handled by the broker: *Route messages to one or more destinations *Transform messages to an alternative representation *Perform message aggregation, decomposing messages into multiple messages and sending them to their destination, then recomposing the responses into one message to return to the user *Interact with an external repository to augment a message or store it *Invoke web services to retrieve data *Respond to events or errors *Provide content and topic-based message routing using the

publish–subscribe pattern In software architecture, publish–subscribe is a messaging pattern where senders of messages, called publishers, do not program the messages to be sent directly to specific receivers, called subscribers, but instead categorize published mes ...

Message brokers are generally based on one of two fundamental architectures: hub-and-spoke and message bus. In the first, a central server acts as the mechanism that provides integration services, whereas with the latter, the message broker is a communication backbone or distributed service that acts on the bus. Additionally, a more scalable multi-hub approach can be used to integrate multiple brokers.

List of message broker software

*Amazon Web Services (AWS
Amazon MQ
*Amazon Web Services (AWS
Kinesis
*

Apache ActiveMQ Apache ActiveMQ is an open source message broker written in Java together with a full Java Message Service (JMS) client. It provides "Enterprise Features" which in this case means fostering the communication from more than one client or server. Su ...

Apache Artemis
*

Apache Kafka Apache Kafka is a distributed event store and stream-processing platform. It is an open-source system developed by the Apache Software Foundation written in Java and Scala. The project aims to provide a unified, high-throughput, low-latency plat ...

Apache Qpid Apache Qpid is an open-source messaging system which implements the Advanced Message Queuing Protocol (AMQP). It provides transaction management, queuing, distribution, security, management, clustering, federation and heterogeneous multi-platfor ...

Apache Pulsar
*Cloverleaf (Enovation Lifeline - NL) *Comverse Message Broker ( Comverse Technology) *Eclipse Mosquitto MQTT Broker (

Eclipse Foundation The Eclipse Foundation AISBL is an independent, Europe-based not-for-profit corporation that acts as a steward of the Eclipse open source software development community, with legal jurisdiction in the European Union. It is an organization suppo ...

) *EMQ
EMQX MQTT Broker
*

Enduro/X Enduro/X is an open-source middleware platform for distributed transaction processing. It is built on proven APIs such as X/Open group's XATMI and XA. The platform is designed for building real-time microservices based applications with a c ...

Transactional Message Queue (TMQ) *Financial Fusion Message Broker (

Sybase Sybase, Inc. was an enterprise software and services company. The company produced software to manage and analyze information in relational databases, with facilities located in California and Massachusetts. Sybase was acquired by SAP in 2010; ...

) * Fuse Message Broker (enterprise ActiveMQ) * Gearman *Google Clou
Pub/Sub
(

Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...

) *HiveM
HiveMQ MQTT Broker
*

HornetQ HornetQ is an open-source asynchronous messaging project from JBoss. It is an example of Message-oriented middleware. HornetQ is an open source project to build a multi-protocol, embeddable, very high performance, clustered, asynchronous messaging ...

(

Red Hat Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide. Red Hat has become a ...

) (Now part of Apache Artemis) * IBM App Connect * IBM MQ * JBoss Messaging (

JBoss WildFly, formerly known as JBoss AS, or simply JBoss, is an application server written by JBoss, now developed by Red Hat. WildFly is written in Java and implements the Java Platform, Enterprise Edition (Java EE) specification. It runs on mu ...

) * JORAM * Microsoft Azure Service Bus (

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ...

) *

Microsoft BizTalk Server Microsoft BizTalk Server is an inter-organizational middleware system (IOMS) that automates business processes through the use of ''adapters'' which are tailored to communicate with different software systems used in an enterprise. Created by M ...

(

)
MigratoryData
(a publish/subscribe

WebSockets WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as in 2011. The current API specification allowing web applications ...

message broker written to address the C10M problem ) * NATS ( MIT Open Source License, written in Go) *NanoM
MQTT Broker for IoT Edge
* Open Message Queue *Oracle Message Broker (

Oracle Corporation Oracle Corporation is an American multinational computer technology corporation headquartered in Austin, Texas. In 2020, Oracle was the third-largest software company in the world by revenue and market capitalization. The company sells da ...

) *

RabbitMQ 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 Stre ...

(

Mozilla Public License The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird The MPL license is developed and maintained by Mozilla, which seeks to balance the conce ...

, written in Erlang) *

Redis Redis (; Remote Dictionary Server) is an in-memory data structure store, used as a distributed, in-memory key–value database, cache and message broker, with optional durability. Redis supports different kinds of abstract data structures, s ...

An open source, in-memory data structure store, used as a database, cache and message broker. * SAP PI (

SAP AG Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant. Sap is distinct from latex, resin, or cell sap; it is ...

) *SM
SMC Platform
*

Solace Consolation, consolement, and solace are terms referring to psychological comfort given to someone who has suffered severe, upsetting loss, such as the death of a loved one. It is typically provided by expressing shared regret for that loss and ...

PubSub+ * Spread Toolkit *

Tarantool Tarantool is an in-memory computing platform with a flexible data schema, best used for creating high-performance applications. Two main parts of it are an in-memory database and a Lua application server. Tarantool maintains data in memory an ...

, a NoSQL database, with a set of

stored procedure A stored procedure (also termed proc, storp, sproc, StoPro, StoredProc, StoreProc, sp, or SP) is a subroutine available to applications that access a relational database management system (RDBMS). Such procedures are stored in the database data d ...

s for message queues * TIBCO Enterprise Message Service * WSO2 Message Broker * ZeroMQ

References

Middleware Software design patterns {{network-software-stub

Overview

Purpose

Life cycle

List of message broker software

See also

References