Architecture

The underlying messaging framework of the WSO2 Message Broker is powered by Andes, one of the distributed message brokering systems which is compatible with leading Advanced Message Queuing Protocol (AMQP)(0-91)). Andes is under apache license and uses Apache Cassandra as its storage.

The following diagram depicts the component-based architecture of the WSO2 Message Broker:

Figure: Andes-component-diagram

Andes broker engine

This is the core engine of WSO2 message broker which handles AMQP messaging, connection/session creation etc.

Andes Authenticator

Users are authenticated so that the instances inside broker can be given ownership. 

Queues

Implements FIFO messaging with message persistence. 

Topics

Allows subscribing for interested events, and broadcast events published. 

Event publisher/subscriber

Enables WS eventing.

Cassandra Database

Cassandra is a highly-scalable, eventually consistent, distributed, structured key-value store which acts as the persistence storage for WSO2 MB. This component is packed with WSO2 MB by default, but can be deployed as an external database also. For instructions on setting up externally, refer to Clustered Deployment.