Aggregate metric field type

Stores pre-aggregated numeric values for metric aggregations. An aggregate_metric_double field is an object containing one or more of the following metric sub-fields: min, max, sum, and value_count.

When you run certain metric aggregations on an aggregate_metric_double field, the aggregation uses the related sub-field’s values. For example, a min aggregation on an aggregate_metric_double field returns the minimum value of all min sub-fields.

 PUT my-index {
  "mappings": {
    "properties": {
      "my-agg-metric-field": {
        "type": "aggregate_metric_double",
        "metrics": [ "min", "max", "sum", "value_count" ],
        "default_metric": "max"
      }
    }
  }
}

metrics

(Required, array of strings) Array of metric sub-fields to store. Each value corresponds to a metric aggregation. Valid values are min, max, sum, and value_count. You must specify at least one value.

default_metric

(Required, string) Default metric sub-field to use for queries, scripts, and aggregations that don’t use a sub-field. Must be a value from the metrics array.

time_series_metric

(Optional, string) Marks the field as a time series metric. The value is the metric type. You can’t update this parameter for existing fields.

Valid `time_series_metric` values for `aggregate_metric_double` fields

gauge

A metric that represents a single numeric that can arbitrarily increase or decrease. For example, a temperature or available disk space.

null (Default)

Not a time series metric.

We designed aggregate_metric_double fields for use with the following aggregations:

• A min aggregation returns the minimum value of all min sub-fields.
• A max aggregation returns the maximum value of all max sub-fields.
• A sum aggregation returns the sum of the values of all sum sub-fields.
• A value_count aggregation returns the sum of the values of all value_count sub-fields.
• A avg aggregation. There is no avg sub-field; the result of the avg aggregation is computed using the sum and value_count metrics. To run an avg aggregation, the field must contain both sum and value_count metric sub-field.

Running any other aggregation on an aggregate_metric_double field will fail with an "unsupported aggregation" error.

Finally, an aggregate_metric_double field supports the following queries for which it behaves as a double by delegating its behavior to its default_metric sub-field:

• exists
• range
• term
• terms

The following create index API request creates an index with an aggregate_metric_double field named agg_metric. The request sets max as the field’s default_metric.

 PUT stats-index {
  "mappings": {
    "properties": {
      "agg_metric": {
        "type": "aggregate_metric_double",
        "metrics": [ "min", "max", "sum", "value_count" ],
        "default_metric": "max"
      }
    }
  }
}

The following index API request adds documents with pre-aggregated data in the agg_metric field.

 PUT stats-index/_doc/1 {
  "agg_metric": {
    "min": -302.50,
    "max": 702.30,
    "sum": 200.0,
    "value_count": 25
  }
}

PUT stats-index/_doc/2
{
  "agg_metric": {
    "min": -93.00,
    "max": 1702.30,
    "sum": 300.00,
    "value_count": 25
  }
}

You can run min, max, sum, value_count, and avg aggregations on a agg_metric field.

 POST stats-index/_search?size=0 {
  "aggs": {
    "metric_min": { "min": { "field": "agg_metric" } },
    "metric_max": { "max": { "field": "agg_metric" } },
    "metric_value_count": { "value_count": { "field": "agg_metric" } },
    "metric_sum": { "sum": { "field": "agg_metric" } },
    "metric_avg": { "avg": { "field": "agg_metric" } }
  }
}

The aggregation results are based on related metric sub-field values.

{
...
  "aggregations": {
    "metric_min": {
      "value": -302.5
    },
    "metric_max": {
      "value": 1702.3
    },
    "metric_value_count": {
      "value": 50
    },
    "metric_sum": {
      "value": 500.0
    },
    "metric_avg": {
      "value": 10.0
    }
  }
}

Queries on a aggregate_metric_double field use the default_metric value.

 GET stats-index/_search {
  "query": {
    "term": {
      "agg_metric": {
        "value": 702.30
      }
    }
  }
}

The search returns the following hit. The value of the default_metric field, max, matches the query value.

{
  ...
    "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1.0,
    "hits": [
      {
        "_index": "stats-index",
        "_id": "1",
        "_score": 1.0,
        "_source": {
          "agg_metric": {
            "min": -302.5,
            "max": 702.3,
            "sum": 200.0,
            "value_count": 25
          }
        }
      }
    ]
  }
}

For example:

 PUT idx {
  "settings": {
    "index": {
      "mapping": {
        "source": {
          "mode": "synthetic"
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "agg_metric": {
        "type": "aggregate_metric_double",
        "metrics": [ "min", "max", "sum", "value_count" ],
        "default_metric": "max"
      }
    }
  }
}

PUT idx/_doc/1
{
  "agg_metric": {
    "min": -302.50,
    "max": 702.30,
    "sum": 200.0,
    "value_count": 25
  }
}

Will become:

{
  "agg_metric": {
    "min": -302.50,
    "max": 702.30,
    "sum": 200.0,
    "value_count": 25
  }
}