Top Metrics Aggregation Usage

The top metrics aggregation selects metrics from the document with the largest or smallest "sort" value.

Top metrics is fairly similar to "top hits" in spirit but because it is more limited it is able to do its job using less memory and is often faster.

Be sure to read the Elasticsearch documentation on Top Metrics Aggregation

Fluent DSL example

edit

a => a
.TopMetrics("tm", st => st
    .Metrics(m => m.Field(p => p.NumberOfContributors))
    .Size(10)
    .Sort(sort => sort
        .Ascending("numberOfContributors")
    )
)

Object Initializer syntax example

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new TopMetricsAggregation("tm")
{
    Metrics = new List<ITopMetricsValue>
    {
        new TopMetricsValue(Field<Project>(p => p.NumberOfContributors))
    },
    Size = 10,
    Sort = new List<ISort> { new FieldSort { Field = "numberOfContributors", Order = SortOrder.Ascending } }
}

Example json output.

{
  "tm": {
    "top_metrics": {
      "metrics": [
        {
          "field": "numberOfContributors"
        }
      ],
      "size": 10,
      "sort": [
        {
          "numberOfContributors": {
            "order": "asc"
          }
        }
      ]
    }
  }
}

Handling Responses

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response.ShouldBeValid();
var topMetrics = response.Aggregations.TopMetrics("tm");
topMetrics.Should().NotBeNull();
topMetrics.Top.Should().NotBeNull();
topMetrics.Top.Count.Should().BeGreaterThan(0);

var tipTop = topMetrics.Top.First();
tipTop.Sort.Should().Should().NotBeNull();
tipTop.Sort.Count.Should().BeGreaterThan(0);
tipTop.Metrics.Should().NotBeNull();
tipTop.Metrics.Count.Should().BeGreaterThan(0);

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