Version upgrade from 8.16.3 to 8.17.0 broken nested mapping type

[nadzk]

In version 8.17.0 mapping for nested fields are not recognized, the "type": "nested" is missing hence queries fail. But when downgrading back to 8.16.3 everything works as expected

Index created in 8.16.3:
{ "test-index": { "aliases": {}, "mappings": { "properties": { "branches": { "type": "nested", "properties": { "id": { "type": "long" }, "services": { "type": "nested", "properties": { "id": { "type": "long" }, "name": { "type": "text", "fields": { "keyword": { "type": "keyword", "ignore_above": 256 } } } } } } } } }, "settings": { "index": { "creation_date": "1705197654049", "number_of_shards": "1", "number_of_replicas": "1", "uuid": "vMprJ3AHSperrvC_sbOvcw", "version": { "created": "7050099" }, "provided_name": "business-index" } } } }

Index created in 8.17.0:
{ "test-index": { "aliases": {}, "mappings": { "properties": { "branches": { "properties": { "id": { "type": "long" }, "services": { "properties": { "type": "text", "fields": { "keyword": { "type": "keyword", "ignore_above": 256 } } }, "id": { "type": "long" }, "name": { "type": "text", "fields": { "keyword": { "type": "keyword", "ignore_above": 256 } } }, } } } } } }, "settings": { "index": { "routing": { "allocation": { "include": { "_tier_preference": "data_content" } } }, "number_of_shards": "1", "provided_name": "test-index", "creation_date": "1736434041031", "number_of_replicas": "1", "uuid": "5SBIB0pjRpe17hVyiTz0kg", "version": { "created": "8080299" } } } } }

Index Mapping:

`
protected override TypeMappingDescriptor ConfigureMappings(TypeMappingDescriptor descriptor)
{
return descriptor
.Properties(p => p
.Nested(n => n.Branches, nd => nd.Properties(np => np
.Keyword(k => k.Branches.First().Id)
.Nested(nn => nn.Branches.First().Services, nnd => nnd.Properties(nnp => nnp
.LongNumber(k => k.Branches.First().Services.First().Id)
.Text(t => t.Branches.First().Services.First().Name))
)))
);
}

var createResponse = await _client.Indices.CreateAsync(IndexName, descriptor => descriptor
.Mappings(mapping => ConfigureMappings(mapping)));
`

Elastic.Clients.Elasticsearch version: 8.17.0

Elasticsearch version: 8.8.2

.NET runtime version : 8.0.11

[flobernd]

Hi @nadzk,

I'm not able to reproduce this. The following example:

var mapping = new TypeMappingDescriptor<X>() // Your code uses a non-generic version here which does not exists!?
    .Properties(p => p
        .Nested(n => n.Branches, nd => nd.Properties(np => np
            .Keyword(k => k.Branches.First().Id)
            .Nested(nn => nn.Branches.First().Services, nnd => nnd.Properties(nnp => nnp
                .LongNumber(k => k.Branches.First().Services.First().Id)
                .Text(t => t.Branches.First().Services.First().Name))
            ))));

await client.Indices.CreateAsync<X>("new_idx", d => d.Mappings(mapping));

public class X
{
    public Y[] Branches { get; set; } = default!;
}

public class Y
{
    public string Id { get; set; } = default!;
    public Z[] Services { get; set; } = default!;
}

public class Z
{
    public string Id { get; set; } = default!;
    public string Name { get; set; } = default!;
}

Produces this valid request:

# Request:
{
  "mappings": {
    "properties": {
      "branches": {
        "properties": {
          "id": {
            "type": "keyword"
          },
          "services": {
            "properties": {
              "id": {
                "type": "long"
              },
              "name": {
                "type": "text"
              }
            },
            "type": "nested"
          }
        },
        "type": "nested"
      }
    }
  }
}

Could you please post a complete reproducer, including the data classes (redacted to only contain the required properties).

[nadzk]

Weirdly I can't reproduce this issue now either, will close the issue. Thanks for the prompt response though. 👍🏻