For some reason, I had a really hard time finding how to setup an XA datasource in JBoss for MySQL. Below is the contents of the file mysql-xa-ds.xml.
jdbc/DataSource
jdbc:mysql://localhost:3306/ordb
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource
root
password
true
org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter
org.jboss.resource.adapter.jdbc.vendor.MySQLValidConnectionChecker
1
10
10
mySQL