You may be confused if you see this:
org.jboss.mq.SpyJMSException: Cannot authenticate user; - nested throwable: (java.net.SocketException: Socket closed)
when a JMS client is trying to connect.
Authentication is attempted when a connection is first established. When a connection is accepted, JBoss attempts to authenticate the client. If the socket is closed, then this exception is generated. The underlying cause is found within the parenthesis: java.net.SocketException: Socket closed.
Connection difficulties may be due to network firewall issues, outages, or OS problems, such as not enough free sockets or files on the server. Or, an unreliable client may be connecting but soon dropping due to issues on the client side.
This might also happen if you start jboss server on a multihomed system and jboss bind's to the "wrong" ip address. Check the console log to what ip address the HA-JNDI service is bound.