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Caution

Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.

Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Open source

otelcol.exporter.prometheus

otelcol.exporter.prometheus accepts OTLP-formatted metrics from other otelcol components, converts metrics to Prometheus-formatted metrics, and forwards the resulting metrics to prometheus components.

NOTE: otelcol.exporter.prometheus is a custom component unrelated to the prometheus exporter from OpenTelemetry Collector.

Conversion of metrics are done according to the OpenTelemetry Metrics Data Model specification.

Multiple otelcol.exporter.prometheus components can be specified by giving them different labels.

Usage

river
otelcol.exporter.prometheus "LABEL" {
  forward_to = [...]
}

Arguments

otelcol.exporter.prometheus supports the following arguments:

NameTypeDescriptionDefaultRequired
include_target_infobooleanWhether to include target_info metrics.trueno
include_scope_infobooleanWhether to include otel_scope_info metrics.trueno
gc_frequencydurationHow often to clean up stale metrics from memory."5m"no
forward_tolist(receiver)Where to forward converted Prometheus metrics.yes

By default, OpenTelemetry resources are converted into target_info metrics, and OpenTelemetry instrumentation scopes are converted into otel_scope_info metrics. Set the include_scope_info and include_target_info arguments to false, respectively, to disable the custom metrics.

When include_scope_info is true, the instrumentation scope name and version are added as otel_scope_name and otel_scope_version labels to every converted metric sample.

When include_scope_info is true, OpenTelemetry Collector resources are converted into target_info metrics.

Exported fields

The following fields are exported and can be referenced by other components:

NameTypeDescription
inputotelcol.ConsumerA value that other components can use to send telemetry data to.

input accepts otelcol.Consumer data for metrics. Other telemetry signals are ignored.

Metrics sent to the input are converted to Prometheus-compatible metrics and are forwarded to the forward_to argument.

The following are dropped during the conversion process:

  • Metrics that use the delta aggregation temporality
  • Exemplars on OpenTelemetry cumulative sums and OpenTelemetry Histograms
  • ExponentialHistogram data points

Component health

otelcol.exporter.prometheus is only reported as unhealthy if given an invalid configuration.

Debug information

otelcol.exporter.prometheus does not expose any component-specific debug information.

Example

This example accepts metrics over OTLP and forwards it using prometheus.remote_write:

river
otelcol.receiver.otlp "default" {
  grpc {}

  output {
    metrics = [otelcol.exporter.prometheus.default.input]
  }
}

otelcol.exporter.prometheus "default" {
  forward_to = [prometheus.remote_write.mimir.receiver]
}

prometheus.remote_write "mimir" {
  endpoint {
    url = "http://mimir:9009/api/v1/push"
  }
}