Queues provide the facility for users to store messages in an intermediate location sent by an external party, and access them on-demand. WSO2 Message Broker uses a Message Queue to facilitate this feature, and all operations are carried out on that message queue. The queuing feature is similar to an inbox where anyone can send messages to and only the owner can consume the messages. Queues enable users to publish messages and receive them in the order that they are sent. These queues are natively persistent, which indicates that even after shutting down the server or a sudden crash happens, the messages still remain in the queue ready to be delivered.
The message queue architecture is depicted in the figure below.
Figure: How Message Queues Work
The Queue management capability in WSO2 Message Broker is provided by the following feature in the WSO2 feature repository.
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 with it using the instructions given in section, Server Provisioning.