Caused by: java.lang.IllegalArgumentException: JBAS011470: Persistence unitName was not specified and there are 2 persistence unit definitions in application deployment deployment "xyz-1.0.ear". Either change the application deployment to have only one persistence unit definition or specify the unitName for each reference to a persistence unit.

The Structure of the persistence.xml looks like the following

persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">

<persistence-unit name="appPersistenceUnit1" transaction-type="JTA">       
   <jta-data-source>java:jboss/datasources/FedDS1</jta-data-source>
    <jar-file>XYZServices-1.0.jar</jar-file>      
    <class>xyz.data.entities.Event</class>   
</persistence-unit>

java:jboss/datasources/FedDS2
XYZServices-1.0.jar
xyz.data.entities.Event

The persistence.xml resides in the ear.