可以用 update-index-settings API 动态修改副本数：
PUT /my_temp_index/_settings
{
"number_of_replicas": 1
}
curl -XPUT http://192.168.0.200:9200/index_execution_20200414/_settings -d '{"number_of_replicas":1}'
curl -XPUT http://192.168.0.200:9200/index_execution_20200414/_settings -d '{"number_of_replicas":0}'