public void start()
      throws Exception {
    metricsReporters.forEach((reporterName, metricsReporter) -> {
      log.info("Registering the metrics reporter : {},  with source :  {}.", reporterName, METRICS_SOURCE);
      metricsReporter.register(METRICS_SOURCE, metricsRegistry);
      log.info("Starting the metrics reporter : {}.", reporterName);
      metricsReporter.start();
    });
    log.info("Starting server on port {}", ((NetworkConnector) server.getConnectors()[0]).getPort());
    server.start();
    log.info("Server is running");
  }
Starts the server asynchronously. To stop the server, see {@link #stop()}.

@throws Exception if the server could not be successfully started.
samza-rest/src/main/java/org/apache/samza/rest/SamzaRestService.java