JBOSS: java.net.ConnectException: Connection refused

Vamos a ir subiendo algunos errores tipicos de jboss que aparecen en el log

WARN  [org.jboss.resource.connectionmanager.JBossManagedConnectionPool] Throwable while attempting to get a new connection: null
org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.net.SocketException
MESSAGE: java.net.ConnectException: Connection refused

STACKTRACE:

java.net.SocketException: java.net.ConnectException: Connection refused

Este es facil, directamente no puede conectar con la base de datos Mysql usando el odbc, asi que hay que comprobar que la base de datos esta levantada, usuario , password, etc…