cache/src/META-INF/protected.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">

    <entity class="model.Order">
        <cache isolation="PROTECTED"/>
    </entity>
    <entity class="model.OrderLine">
        <cache isolation="PROTECTED"/>
    </entity>
    <entity class="model.Customer">
        <cache isolation="PROTECTED"/>
    </entity>

</entity-mappings>