code: private void setAliveDeadMetrics() {
      clusterManager.getMetrics().setAliveNodes(nameToNode.size());
      int totalHosts = hostsReader.getHosts().size();
      if (totalHosts > 0) {
        clusterManager.getMetrics().setDeadNodes(
            totalHosts - nameToNode.size());
      }
    }
docs: Update metrics for alive/dead nodes.