la búsqueda se trata de javaee6 con glassfish incrustado y búsqueda de derby jndi incrustada para la fuente de datos en el momento del despliegue antes de ejecutar la prueba unitaria ...

Encuentre el persistence.xml aquí ...

<?xml version="1.0" encoding="UTF-8"?>
<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="mymodulePU" transaction-type="JTA">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> 
        <jta-data-source>jdbc/__default</jta-data-source>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:derby:C:/myappDB;create=true" />
            <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
            <property name="eclipselink.ddl-generation.output-mode"
                value="database" />
            <property name="eclipselink.logging.level" value="ALL" />
            <property name="eclipselink.logging.file" value="./target/eclipselink.logs" />
        </properties>
    </persistence-unit>
</persistence>

Busque el registro de la consola del servidor aquí cuando se ejecute la prueba de la unidad ...

Jan 24, 2011 5:12:44 PM com.sun.enterprise.resource.allocator.LocalTxConnectorAllocator createResource
WARNING: poolmgr.create_resource_error
Jan 24, 2011 5:12:44 PM com.sun.enterprise.connectors.ConnectionManagerImpl internalGetConnection
WARNING: poolmgr.get_connection_failure
Jan 24, 2011 5:12:44 PM com.sun.gjc.spi.base.DataSource getConnection
WARNING: jdbc.exc_get_conn
Jan 24, 2011 5:12:44 PM org.eclipse.persistence.session.file:/C:/DD/WORKSPACES/lean-soa-arch/entities/target/classes/_mymodulePU.ejb
SEVERE: 
Local Exception Stack: 
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: Error in allocating a connection. Cause: Connection could not be allocated because: java.net.ConnectException : Error connecting to server localhost on port 1527 with message Connection refused: connect.
Error Code: 0
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:309)
......
.......
......
Caused by: java.sql.SQLException: Error in allocating a connection. Cause: Connection could not be allocated because: java.net.ConnectException : Error connecting to server localhost on port 1527 with message Connection refused: connect.
    at com.sun.gjc.spi.base.DataSource.getConnection(DataSource.java:112)
    at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:126)
    ... 44 more
Jan 24, 2011 5:12:44 PM org.eclipse.persistence.session.file:/C:/DD/WORKSPACES/lean-soa-arch/entities/target/classes/_mymodulePU.properties
FINEST: End deploying Persistence Unit mymodulePU; session file:/C:/DD/WORKSPACES/lean-soa-arch/entities/target/classes/_mymodulePU; state Deployed; factoryCount 1