// Setup a destination policy where it takes only 1 message at a time.
PolicyMap policyMap = new PolicyMap();
PolicyEntry policy = new PolicyEntry();
policy.setMemoryLimit(1);
policy.setPendingSubscriberPolicy(new VMPendingSubscriberMessageStoragePolicy());
policy.setPendingQueuePolicy(new VMPendingQueueMessageStoragePolicy());
policy.setProducerFlowControl(true);
policyMap.setDefaultEntry(policy);
service.setDestinationPolicy(policyMap);
connector = service.addConnector("tcp://localhost:0");