private void logAllSettings(Config config) {
    StringBuilder b = new StringBuilder();
    b.append("Elasticsearch System settings: ");
    b.append("\n");
    for (Map.Entry<String, String> entry : config.entrySet()) {
      b.append('\t');
      b.append(entry.getKey());
      b.append(" = ");
      b.append(entry.getValue());
      b.append("\n");
    }
    LOGGER.info(b.toString());
  }
Elasticsearch configuration class to read elasticsearch specific configuration from Samza.
samza-elasticsearch/src/main/java/org/apache/samza/config/ElasticsearchConfig.java