Delete child documents without parent

[ilijaplusx]

As the title says, I'm trying to delete all the parentless child documents using Jest. If I got things correctly, I need to use DeleteByQuery, and my proposed solution is this:

val allParentlessChildren = QueryBuilders
    .boolQuery()
    .mustNot(JoinQueryBuilders.hasParentQuery(
      "my_parent",
      QueryBuilders.matchAllQuery(),
      false)
    )
val delete = new DeleteByQuery.Builder(allParentlessChildren.toString)
    .addIndex("my_index")
    .addType("my_child")
    .build()

However, I get routing_missing_exception. Investigating online, it seems I need to set parent type for routing, however, apart from specifying it in hasParentQuery idk where else I need to add it?

Although I found some examples how to do it with REST API, I wasn't able to find ones that use Jest, so hopefully someone can help out.

I'm using Elasticsearch 5.5.

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