참고사이트
https://discuss.elastic.co/t/how-to-cancel-search-using-the-task-management-api/73842
https://www.elastic.co/guide/en/elasticsearch/reference/6.0/search.html#global-search-cancellation
https://www.elastic.co/guide/en/elasticsearch/reference/6.0/tasks.html#_current_tasks_information
