The entire code base except Artemis is under our control. The vast majority of the messages are delivering fast ,more than 99.999. The use case:
An API submits a POST request, we form a message and stick it into a queue. The queue has 10 listeners. When these listeners receive a Message, they write info to DB and then send email. In most cases, this process takes a few seconds (mostly due to delay in SMTP). However, some messages are stuck in a queue for more than 12 hours, for no apparent reason. -- Sent from: http://activemq.2283324.n4.nabble.com/ActiveMQ-User-f2341805.html