1) It is an FAQ and you haven't looked hard enough
2) It is a question about clustered ejb deployment so you are in the wrong forum
clustering => clustering forum
3) I added it to the JMS FAQ about MDB singleton
4) Eventually the JMS FAQ is just going to be bigger as big as this forum :-(
Thanks. I didn't make the connection between my question and "MDB singleton" because in my scenario, there may be as many MDB instances as appropriate. Several messages may be processed in parallel, even on different nodes, as long as every message is only processed once.
Concerning (4): Why not put the information in the documentation instead, e.g. 5.5 "Message driven beans in cluster configurations"