如何更改NEST（ElasticSearch）滚动请求的索引？

Question

We have two indexes for each document type, a draft and a published index. Normally setting the index we want to work with is easy but I can't see how to do it with the scroll API.

The initial request is ok.

var query = new SearchDescriptor<MyDoc>()
            .Index(MyDoc.DraftIndexName) <-- we can switch them here
            // Or .Index(MyDoc.PublishedIndexName)
            .Size(pageSize)
            .Query(q =>
                 ...
            ))
            .Scroll("2m");

but when I want to get the next page

var request = new ScrollDescriptor<MyDoc>()
                .ScrollId(scrollId)
                .Scroll(new Time("2m"));
                // Nowhere to set the index


var scrollResponse = await client.ScrollAsync<EsPerson>(request);

I assume it will always use the default index via inference which is the draft one.

Answer 1

The start of scrolling is initiated with a request to the search API, which returns a scroll ID in the response. After that, the scroll ID from a response is passed to the scroll API to continue scrolling through all documents, repeating until no more documents are returned. All subsequent scroll API calls will use the configuration of the initial API call, including the index/indices targeted.

If scrolling is considered to be like a server-side cursor, where the initial request defines the parameters for scrolling, it doesn't make much sense to be able to change these parameters mid-scroll .