Problem

How to configure embedded ActiveMQ Brokers as a network of brokers?

Resolution

For a Group of API gateway instances change the configuration so that the 'Enabled Embedded ActiveMQ Broker' setting is checked.

Also check the 'Communicate with brokers in the same group' setting.

Also, the Shared Directory MUST actually be a network share that is accessible from all instances in the group (NFSv4 recomended).

Then set up at least one JMS Consumer for this configuration.

With this setup you should have a network of JMS brokers (API Gateway instances in a group with embedded ActiveMQ enabled).
See details on configuring a JMS consumer here: https://docs.axway.com/bundle/APIGateway_753_PolicyDevGuide_allOS_en_HTML5/page/Content/PolicyDevTopics/general_messaging_consumer.htm.

When the instances have JMS consumers configured for a queue then the queues should be propagated (and messages routed to all instances). Note, see KB 181087 for more info on that.