Sigma should be a double? on ExtendedStatsBucketAggregation

[russcam]

NEST/Elasticsearch.Net version: 2.1.0

Elasticsearch version: 2.3.0

Description of the problem including expected versus actual behavior:

Sigma is specified as an int? on ExtendedStatsBucketAggregation but it should be a double? (based on the docs of Extended Stats Aggregation).

Sending a number without decimal places throws a parse exception on Elasticsearch 2.3.0:

Request:

{
  "size": 0,
  "aggs": {
    "projects_started_per_month": {
      "date_histogram": {
        "field": "startedOn",
        "interval": "month"
      },
      "aggs": {
        "commits": {
          "sum": {
            "field": "numberOfCommits"
          }
        }
      }
    },
    "extended_stats_commits_per_month": {
      "extended_stats_bucket": {
        "buckets_path": "projects_started_per_month>commits",
        "sigma": 2
      }
    }
  }
}

Response:

  "error" : {
    "root_cause" : [ {
      "type" : "parse_exception",
      "reason" : "Parameter [sigma] must be a Double, type `Integer` provided instead"
    } ],
    "type" : "search_phase_execution_exception",
    "reason" : "all shards failed",
    "phase" : "query",
    "grouped" : true,
    "failed_shards" : [ {
      "shard" : 0,
      "index" : "project",
      "node" : "afZfSF7hQoqmZQip5n3-LQ",
      "reason" : {
        "type" : "parse_exception",
        "reason" : "Parameter [sigma] must be a Double, type `Integer` provided instead"
      }
    } ]
  },
  "status" : 500
}

Steps to reproduce:

1. Run the ExtendedStatsBucketAggregationUsageTests.
2. Changing Sigma to double? fixes the problem. This would be a binary break for NEST 2.x however 😞

See also elastic/elasticsearch#17499 - I filed an issue as I think Elasticsearch should also accept an integer value for sigma (and deserialize to double on the server side).

[jonyadamit]

@russcam How would this be a breaking change, when ExtendedStatsBucketAggregation hasn't been released yet?

[russcam]

@jonyadamit My bad, I thought it'd gone into 2.1.0 but I was looking at ExtendedStatsAggregation - will close this issue and change it to double? 👍

[gmarz]

👍 I had actually made this change in master (7273f55) but never cherry picked it to 2.x.