ExtendedStats with one document -> UnexpectedElasticsearchClientException

NEST/Elasticsearch.Net version: 7.9.0 Elasticsearch version: 7.9.1

Description of the problem including expected versus actual behavior: Using ExtendedStats on a numeric value on one document generates always an exception:

    "message": "An error has occurred.",
    "exceptionMessage": "expected:'Number Token', actual:'\"NaN\"', at offset:179002",
    "exceptionType": "Elasticsearch.Net.UnexpectedElasticsearchClientException",

ps: I really don’t know if the issue was present before, actually we working usually with a lot of documents, so this is the first time we see only one document after filtering our index and the first time in years that we see this exception.

Expected behavior No exception but an empty result.

[russcam]

I’ve opened https://github.com/elastic/elasticsearch-net/pull/5404 to address

[russcam]

Hi @meriturva

there’s no change in NEST for this yet. There’s been some discussion about whether Elasticsearch should be returning NaN at all, given the ambiguity of representing it in JSON. No conclusion has been reached yet though.

@Mpdreamz, @stevejgordon perhaps we can check for "NaN" in the offending fields? I think it’s the addition of the sampling fields in extended stats, but would need double checking.