Re: Unfortunately, I don't see the messages that had been published to the topic before I've added my subscriber.
That's expected behavior.
Re: Which way is the best to see all the messages that have been published on that topic since the begining without removing them?
Did you try jmx-console? Also you can do it programatically as the operations are defined in mbeans.
Yes, listing all subscriptions and then getting the messages for each subscription solves my problem.