Elasticsearch 批量 api 的默认“路由”参数是什么?

What is the default `routing` parameter for Elasticsearch's bulk api?

来自elastic docs

The default value used for _routing is the document’s _id(关于 PUT api)

但我找不到 bulk api documentation

的任何默认值

我应该手动设置 _routing 映射还是有默认值?

您需要在每个命令行中提供routing value

                                                 here
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                                                   v
{ "index" : { "_index" : "test", "_id" : "1", "_routing": 123 } }
{ "field1" : "value1" }