@Override
  public void stopManager() {
    synchronized (instances) {
      verifyManagementService();
      if (federatingManager != null) {
        federatingManager.stopManager();
        system.handleResourceEvent(ResourceEvent.MANAGER_STOP, null);
        cache.getJmxManagerAdvisor().broadcastChange();
        if (agent != null && agent.isRunning()) {
          agent.stopAgent();
        }
      }
    }
  }
It will stop the federating Manager and restart the Local cache operation
geode-core/src/main/java/org/apache/geode/management/internal/SystemManagementService.java