private T loadInstance() {
    if (jpaStarted.get()) {
      LOGGER.info("Loading {} configuration data", configurationCategory.getCategoryName());
      T instance = loadInstance(ambariConfigurationDAOProvider.get().findByCategory(configurationCategory.getCategoryName()));
      encryptor.decryptSensitiveData(instance);
      return instance;
    } else {
      LOGGER.info("Cannot load {} configuration data since JPA is not initialized", configurationCategory.getCategoryName());
      if (instance == null) {
        return loadInstance(Collections.emptyList());
      } else {
        return instance;
      }
    }
  }
Attempts to load the relevant configuration data.
<p>
If the JPA infrastructure has not been initialized, return the instance data that has already
been set up or (if null) requests an empty instance.

@return the loaded instance data
ambari-server/src/main/java/org/apache/ambari/server/configuration/AmbariServerConfigurationProvider.java