Instance Specific EMS Listeners
Each instance is configured to exclusively listen to southbound replies that include an 'originator' EMS header, facilitated by JMS selectors. The JMS selectors create these listeners. Every instance creates listeners with the header name 'originator' and value as the instance ID of the instance. An orchestrator, for instance, processes only the messages for orders that it owns.
After the message is picked, it is queued for the InternalOrderProcessor
worker thread. Each order is processed exclusively by one InternalOrderProcessor
thread, ensuring that all related messages or events are handled by a single thread and eliminating the need for order locking.
If a southbound system's reply lacks the 'originator' header, the Broker service routes the message to the correct owner instance. For more information, see 'Listener for Southbound Reply Queues (With no Originator)' topic in the Broker Service.