code: def fetch_max(self, cluster, metric, topology, component, instance, timerange, environ=None):
      '''
      :param cluster:
      :param metric:
      :param topology:
      :param component:
      :param instance:
      :param timerange:
      :param environ:
      :return:
      '''
      components = [component] if component != "*" else (yield get_comps(cluster, environ, topology))
  
      result = {}
      futures = []
      for comp in components:
        query = self.get_query(metric, comp, instance)
        max_query = "MAX(%s)" % query
        future = get_metrics(cluster, environ, topology, timerange, max_query)
        futures.append(future)
  
      results = yield futures
  
      data = self.compute_max(results)
  
      result = self.get_metric_response(timerange, data, True)
  
      raise tornado.gen.Return(resultf fetch_max(self, cluster, metric, topology, component, instance, timerange, environ=None):
      '''
      :param cluster:
      :param metric:
      :param topology:
      :param component:
      :param instance:
      :param timerange:
      :param environ:
      :return:
      '''
      components = [component] if component != "*" else (yield get_comps(cluster, environ, topology))
  
      result = {}
      futures = []
      for comp in components:
        query = self.get_query(metric, comp, instance)
        max_query = "MAX(%s)" % query
        future = get_metrics(cluster, environ, topology, timerange, max_query)
        futures.append(future)
  
      results = yield futures
  
      data = self.compute_max(results)
  
      result = self.get_metric_response(timerange, data, True)
  
      raise tornado.gen.Return(result)
docs: :param cluster:
      :param metric:
      :param topology:
      :param component:
      :param instance:
      :param timerange:
      :param environ:
      :return: