apex-app-archetype/src/main/resources/archetype-resources/src/site/conf/my-app-conf1.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<configuration>
  <property>
    <name>apex.attr.MASTER_MEMORY_MB</name>
    <value>1024</value>
  </property>
  <property>
    <name>apex.application.MyFirstApplication.operator.randomGenerator.prop.numTuples</name>
    <value>1000</value>
  </property>
</configuration>