You should set unique password for all instances. To do that set it like this:
I check the configuration of our all Jboss server instances and find there is only "<attribute name="SuckerPassword"></attribute>" there. What does this mean? No password or default password?
If I set the SuckerPassword as you wrotem, for exampel:
Should I restart the JBoss instance and what an influce will happend to the applications which deployted on it? I hope there should be no any influence.
Besdies, I read fomr the document from RedHat that
"JBoss Messaging internally makes connections between nodes in order to redistribute messages between clustered destinations. These connections are made with the user name of a special reserved user. On this parameter you define the password used as these connections are made. After JBossMessaging 1.4.1.GA you will need to define the Sucker Password on the ServerPeer and on the SecurityMetadataStore."
I wonder what is this special reserved user?