@Override
  public CoordinatorCommunication coordinatorCommunication(CoordinatorCommunicationContext context) {
    ClusterManagerConfig clusterManagerConfig = new ClusterManagerConfig(context.getConfigForFactory());
    JobModelHttpServlet jobModelHttpServlet = new JobModelHttpServlet(context.getJobInfoProvider(),
        new JobModelHttpServlet.Metrics(context.getMetricsRegistry()));
    HttpServer httpServer = new HttpServer("/", clusterManagerConfig.getCoordinatorUrlPort(), null,
        new ServletHolder(DefaultServlet.class));
    httpServer.addServlet("/", jobModelHttpServlet);
    return new HttpCoordinatorCommunication(httpServer);
  }
Implements HTTP-based communication between the coordinator and workers.
samza-core/src/main/java/org/apache/samza/coordinator/communication/HttpCoordinatorToWorkerCommunicationFactory.java