https://issues.apache.org/jira/browse/AMQ-3195 - NetworkConnector initialization should be backed by an executor added new broker attribute networkConnectorStartAsync (default false) that will cause network connectors to be started in seperate threads such that a block of one does not effect the rest
activemq/trunk/activemq-core/src/main/java/org/apache/activemq/broker/BrokerService.java