archaius-core/src/main/java/com/netflix/config/ConfigurationManager.java
public static void loadCascadedPropertiesFromResources(String configName) throws IOException {
        Properties props = loadCascadedProperties(configName);
        if (instance instanceof AggregatedConfiguration) {
            ConcurrentMapConfiguration config = new ConcurrentMapConfiguration();
            config.loadProperties(props);
            ((AggregatedConfiguration) instance).addConfiguration(config, configName);
        } else {
            ConfigurationUtils.loadProperties(props, instance);
        }
    }
public static void loadCascadedPropertiesFromResources(String configName) throws IOException {
        Properties props = loadCascadedProperties(configName);
        if (instance instanceof AggregatedConfiguration) {
            ConcurrentMapConfiguration config = new ConcurrentMapConfiguration();
            config.loadProperties(props);
            ((AggregatedConfiguration) instance).addConfiguration(config, configName);
        } else {
            ConfigurationUtils.loadProperties(props, instance);
        }
    }
Load resource configName.properties first. Then load configName-deploymentEnvironment.properties
into the system wide configuration. For example, if configName is "application", and deployment environment
is "test", this API will first load "application.properties", then load "application-test.properties" to
override any property that also exist in "application.properties".

@param configName prefix of the properties file name.
@throws IOException
@see DeploymentContext#getDeploymentEnvironment()