cache/src/META-INF/in-memory.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings version="2.4"
    xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/orm"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <named-query name="findOrdersByCustomer">
        <query>Select o from Order o where o.customer.id = :customerId</query>
        <hint name="eclipselink.cache-usage" value="CheckCacheOnly"/>
    </named-query>
    <entity class="model.Order">
        <cache type="FULL"/>
    </entity>
    <entity class="model.OrderLine">
        <cache type="FULL"/>
    </entity>
    <entity class="model.Customer">
        <cache type="FULL"/>
    </entity>

</entity-mappings>