Defaulting to native/exponential histograms

docs/sources/configure/export-data.md

@@ -70,7 +70,7 @@ otel_metrics_export:
   features: ["network", "network_inter_zone"]
   buckets:
     duration_histogram: [0, 1, 2]
-  histogram_aggregation: base2_exponential_bucket_histogram
+  histogram_aggregation: explicit_bucket_histogram
 ```
 
 | YAML<p>environment variable</p>                                                              | Description                                                                                                                                                                                                                                                                                                                                                    | Type            | Default                     |
@@ -85,7 +85,7 @@ otel_metrics_export:
 | `allow_service_graph_self_references`<p>`BEYLA_OTEL_ALLOW_SERVICE_GRAPH_SELF_REFERENCES`</p> | Controls if Beyla includes self-referencing services in service graph generation, for example a service that calls itself. Self referencing reduces service graph usefulness and increases data cardinality.                                                                                                                                                   | boolean         | `false`                     |
 | `instrumentations`<p>`BEYLA_OTEL_METRICS_INSTRUMENTATIONS`</p>                               | The list of metrics instrumentation Beyla collects data for, refer to [metrics instrumentation](#metrics-instrumentation) section.                                                                                                                                                                                                                             | list of strings | `["*"]`                     |
 | `buckets`                                                                                    | Sets how you can override bucket boundaries of diverse histograms, refer to [override histogram buckets](../metrics-histograms/).                                                                                                                                                                                                                              | (n/a)           | Object                      |
-| `histogram_aggregation`<p>`OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION`</p>     | Sets the default aggregation Beyla uses for histogram instruments. Accepted values [`explicit_bucket_histogram`](https://opentelemetry.io/docs/specs/otel/metrics/sdk/#explicit-bucket-histogram-aggregation) or [`base2_exponential_bucket_histogram`](https://opentelemetry.io/docs/specs/otel/metrics/sdk/#base2-exponential-bucket-histogram-aggregation). | `string`        | `explicit_bucket_histogram` |
+| `histogram_aggregation`<p>`OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION`</p>     | Sets the default aggregation Beyla uses for histogram instruments. Accepted values [`explicit_bucket_histogram`](https://opentelemetry.io/docs/specs/otel/metrics/sdk/#explicit-bucket-histogram-aggregation) or [`base2_exponential_bucket_histogram`](https://opentelemetry.io/docs/specs/otel/metrics/sdk/#base2-exponential-bucket-histogram-aggregation). | `string`        | `base2_exponential_bucket_histogram` |
 
 ### Metrics export protocol
 

docs/sources/configure/metrics-histograms.md

@@ -22,6 +22,7 @@ For example:
 
 ```yaml
 otel_metrics_export:
+  histogram_aggregation: explicit_bucket_histogram
   buckets:
     duration_histogram: [0, 1, 2]
 ```
@@ -76,4 +77,5 @@ These default values are UNSTABLE and may change if Prometheus or OpenTelemetry
 
 For Prometheus, you enable [native histograms](https://prometheus.io/docs/concepts/metric_types/#histogram) by [enabling the `native-histograms` feature in your Prometheus collector](https://prometheus.io/docs/prometheus/latest/feature_flags/#native-histograms).
 
-For OpenTelemetry, you can use [exponential histograms](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#exponentialhistogram) for the predefined histograms instead of defining the buckets manually. Set the standard [OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION](https://opentelemetry.io/docs/specs/otel/metrics/sdk_exporters/otlp/#additional-configuration) environment variable. See the `histogram_aggregation` section in the [OTEL metrics exporter](../export-data/) section for more information.
+For OpenTelemetry, Beyla is configured to export [exponential histograms](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#exponentialhistogram)
+by default. See `histogram_aggregation` in the [OTEL metrics exporter](../export-data/) section for more information.

pkg/beyla/config.go

@@ -80,6 +80,8 @@ func DefaultConfig() *Config {
 		{InstrumentableType: svc.InstrumentableNodejs},
 		{InstrumentableType: svc.InstrumentablePython},
 	}
+	// Overrides histogram configuration to use exponential/native histograms by default
+	def.OTELMetrics.HistogramAggregation = otelcfg.HistogramAggregationExponential
 
 	def.Routes.Unmatch = transform.UnmatchLowCardinality