The NASTEL.APTM.MESSAGE queue reaches its maximum queue depth. The queue became full. After recycling nsqtacon, the queue was quickly drained.
The TransactionWorks probe exit captures messages passing through and places them in this queue based on queues selected for processing. The process nsqtacon reads the messages off this queue and sends the data via TCP to the transaction analyzer. During peaks of activity in MQ, this queue will have messages in it.
It should only be considered a problem if the queue is not open for input and messages are not getting processed.
If messages are being processed but not fast enough, perhaps due to latency with the transaction analyzer, increase the number of threads being used by nsqtacon (-T parameter). This will increase the number of messages per second that it can process and send.
The transaction analyzer probe statistics can be used to get the volume of messages processed and the most recent messages.