https://issues.apache.org/jira/browse/AMQ-3473 - Messages (possibly) stuck and pending messages count showing high number of pending message which do not get sent to a consumer. resolve the error in queue stats, message count and enqueue count when index suppressed a duplicate message add attempt
activemq/trunk/activemq-core/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java