You shouldn't have any problems with that on JBoss Messaging 1.4. I just ran a quick test where I had thousand subscribers and it ran without any problems. When i say you shouldn't have any problems, I'm assuming you are designing your application well and you have considered resource usage on the server (max Openfiles set for the number of clients you will have, enough I/O and enough memory on the server and JVM). If your consumers are local to the server, you should probably avoid ObjectMessage as Serialization will aways be something expensive (but that should be ok if your consumers are distributed. On the server side an ObjectMessage is just a ByteArray, but on the client that is using ObjectINputStream and if you have all the clients on the same server that will use more CPU power. (Those recommendations will apply to any system you choose.. not just JBM) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4193627#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...