Reloading configs using commons-configurations2 Not working

Question

I'm using Apache commons-configurations2 (v2.10.1) to load app configs and reload some of the property files dynamically using a ReloadCombinedConfigrationBuilder, however the reload is not working.

Here is my configuration.xml

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<configuration>
    <header>
        <fileSystem config-class="org.apache.commons.configuration2.io.DefaultFileSystem"/>
        <result>
            <nodeCombiner config-class="org.apache.commons.configuration2.tree.OverrideCombiner"/>
            <listDelimiterHandler config-class="org.apache.commons.configuration2.convert.DefaultListDelimiterHandler">
                <config-constrarg config-value="|"/>
            </listDelimiterHandler>
        </result>
    </header>
    <override>
        <system/>
        <properties fileName="app1.properties" config-name="app1Properties" config-optional="true" config-reload="true" reloadingRefreshDelay="5000"/>
                <properties fileName="bootstrap.properties"/>
    </override>
</configuration>

Here is my code snippet.

Parameters params = new Parameters();

      ReloadingCombinedConfigurationBuilder combinedBuilder =
          new ReloadingCombinedConfigurationBuilder()
              .configure(params.fileBased().setFileName("configuration.xml"));

      // without this, the combinedBuilder.getReloadingController() is coming null and a NPE is thrown
      combinedBuilder.getConfiguration();

      // Register an event listener for triggering reloading checks
      combinedBuilder.addEventListener(ConfigurationBuilderEvent.CONFIGURATION_REQUEST,
              (EventListener) event -> combinedBuilder.getReloadingController().checkForReloading(null));

      // apache guide suggests to have this line as well
      combinedBuilder.getReloadingController().addEventListener(
              ReloadingEvent.ANY,  event -> event.getController().resetReloadingState());

      PeriodicReloadingTrigger trigger = new PeriodicReloadingTrigger(combinedBuilder.getReloadingController(),
              null, 60, TimeUnit.SECONDS);
      trigger.start();

      return combinedBuilder.getConfiguration();

Here is the app1.properties which I'm expecting to reload a changed property value.

server.host=api-dev.testserver.com

1. At runtime, I expect it to connect to api-qa.testserver.com after a reload and I don't see that working.
2. Also, I want to add log statements to know that the app1.properties file actually reloaded. How can it be done?

Appreciate your help.

I referred to the common-configurations2 guide and implemented steps as explained. I also verified on stackoverflow thread, but that didn't help