How to implement virtual topic functionality in ActiveMQ Artemis

Question

ActiveMQ "Classic" has virtual topic functionality. This means that consumers can be created dynamically. How is this feature managed by ActiveMQ Artemis?

Answer 1

The point of virtual topics in ActiveMQ "Classic" was to deal with a particular limitation of JMS topics - the fact that only one consumer can be connected to a subscription at a time. Thus virtual topics allowed applications to send to a JMS topic and consume from a JMS queue since queues don't limit the number of consumers like subscriptions do.

ActiveMQ Artemis solves this problem in two ways.

1. It provides full implementation of JMS 2. The shared subscription functionality available in JMS 2 eliminates the need for virtual topics, and since this is a standard part of JMS 2 that means the same application code can be used with any broker which implements JMS 2. This solves one of the main disadvantages of virtual topics which is vendor lock-in.
2. The fundamental address model of ActiveMQ Artemis and the way JMS maps onto that model means that a "JMS subscription" is always represented as a core queue and any client (whether is uses JMS 2 or not) can use the fully qualified queue name to access that queue.

ActiveMQ Artemis also has special support for legacy ActiveMQ "Classic" clients which use virtual topic syntax.