def _update(self, values):
        assert self.query.can_filter(), \
                "Cannot update a query once a slice has been taken."
        query = self.query.clone(sql.UpdateQuery)
        query.add_update_fields(values)
        self._result_cache = None
        return query.get_compiler(self.db).execute_sql(None)
Gives the cluster name
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/models/query.py/QuerySet._update--crossover with--dataset/ETHPy150Open pycassa/pycassa/pycassa/system_manager.py/SystemManager.describe_cluster_name