code: def get(self, cluster, environ, topology, instance):
      '''
      :param cluster:
      :param environ:
      :param topology:
      :param instance:
      :return:
      '''
      pplan = yield access.get_physical_plan(cluster, environ, topology)
      host = pplan['stmgrs'][pplan['instances'][instance]['stmgrId']]['host']
      result = json.loads((yield access.get_instance_pid(
          cluster, environ, topology, instance)))
      self.write('<pre><br/>$%s>: %s<br/><br/>%s</pre>' % (
          host,
          tornado.escape.xhtml_escape(result['command']),
          tornado.escape.xhtml_escape(result['stdout']))f get(self, cluster, environ, topology, instance):
      '''
      :param cluster:
      :param environ:
      :param topology:
      :param instance:
      :return:
      '''
      pplan = yield access.get_physical_plan(cluster, environ, topology)
      host = pplan['stmgrs'][pplan['instances'][instance]['stmgrId']]['host']
      result = json.loads((yield access.get_instance_pid(
          cluster, environ, topology, instance)))
      self.write('<pre><br/>$%s>: %s<br/><br/>%s</pre>' % (
          host,
          tornado.escape.xhtml_escape(result['command']),
          tornado.escape.xhtml_escape(result['stdout'])))
docs: :param cluster:
      :param environ:
      :param topology:
      :param instance:
      :return: