code: def run_metrics(command, parser, cl_args, unknown_args):
    
    cluster, role, env = cl_args['cluster'], cl_args['role'], cl_args['environ']
    topology = cl_args['topology-name']
    try:
      result = tracker_access.get_topology_info(cluster, env, topology, role)
      spouts = result['physical_plan']['spouts'].keys()
      bolts = result['physical_plan']['bolts'].keys()
      components = spouts + bolts
      cname = cl_args['component']
      if cname:
        if cname in components:
          components = [cname]
        else:
          Log.error('Unknown component: \'%s\'' % cname)
          raise
    except Exception:
      Log.error("Fail to connect to tracker: \'%s\'", cl_args["tracker_url"])
      return False
    cresult = []
    for comp in components:
      try:
        metrics = tracker_access.get_component_metrics(comp, cluster, env, topology, role)
      except:
        Log.error("Fail to connect to tracker: \'%s\'", cl_args["tracker_url"])
        return False
      stat, header = to_table(metrics)
      cresult.append((comp, stat, header))
    for i, (comp, stat, header) in enumerate(cresult):
      if i != 0:
        print('')
      print('\'%s\' metrics:' % comp)
      print(tabulate(stat, headers=header))
    return True
docs: run metrics subcommand