A new feature that we are working on that we are very excited about is the addition of the pubsub communication model for XATMI services. You can track our work on this here.
What this will mean is that user code will be able to send a single notification to multiple services using the standard XATMI API.
"ServiceA" is advertised on Server 1
"ServiceA" is also advertised on Server 2
When the client sends the request to "ServiceA", this would typically be handled by a single instance of the service, however, if, ServiceA is configured with a type="topic" attribute in the servers btconfig.xml, that same message would be received by all instances! An example of where this is useful would be for event notification such as for stock ticker symbols or more trivially/importantly (depending on your point of view), a chat room.
Significantly, this will all be achieved using the standard XATMI API with the only caveat being that all requests are sent with the tpacall method and TPNOREPLY set as the client cannot receive multiple responses to the same invocation.
This issue is currently scheduled in for M1 of the 3.0.0 release so please do comment on the Jira or in our forums if you have any further suggestions for us in this area...