Wildfly JMS server master and slave behavior

Question

I'm looking for the easiest way to build a Wildfly cluster with JMS load balancing for a development platform. Messages will be produced by the Wildfly servers themselves.

I wonder how works the ActiveMQ Artemis JMS server embedded in Wildfly in a cluster deployment. I see on this site that a Wildfly node can declare its JMS server as master or slave.

I also read here that a MDB can use an "in-vm-connector" connector.

I'm not sure that I understand how a JMS cluster works with a master and a slave JMS server with "in-vm-connector". Will the MDB instances in the Wildfly node with the slave JMS server receive messages? Will the JMS cluster provide load balancing or will there be only one active JMS server at the same time?

Answer 1

In ActiveMQ Artemis (i.e. the JMS broker embedded into WildFly) clustering (which provides things like message load balancing) and high-availability (which provides redundancy for the integrity of the message data) are separate concepts. The master/slave configuration you mentioned is for high-availability. This configuration doesn't provide message load balancing since only one of the brokers is alive at any given point in time.

If you want configure a master/slave pair it's recommended that you separate those servers from the servers that actually process the messages since it doesn't make sense to have MDBs running on a server which doesn't have a live broker (i.e. a slave) since they won't receive any messages.