In messaging systems, message routing is done on the basis of a concept called Topics: First, we need to have topics created in the message broker (WSO2 MB). A JMS client can then be configured to publish messages to this topic and other JMS clients can be configured as subscribers of this topic. When the publisher sends a message to the topic, it will be dispatched to all the JMS clients that are subscribed to that topic.
For example, consider that we have a topic called 'SportsNews' created in the message broker. We can now have users (JMS clients) publishing messages related to sports news to this topic. Users (JMS clients) that are interested in sports news can subscribe to this topic and receive the messages that are published.
The following diagram depicts how messages are published to topics and how subscribers consume the messages:
The capability of managing topics and subscriptions in WSO2 Message Broker is provided by the following features in the WSO2 feature repository:
Name: WSO2 Carbon - Event Feature
Identifier: org.wso2.carbon.event.feature.group
Name: WSO2 Carbon - Feature - Andes
Identifier: org.wso2.carbon.andes.feature.group
This feature can be removed or added to a different distribution if it is not already bundled as described in Working with Features.