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Documentation Grafana Alloy Collect and forward data Collect Datadog traces and metrics

Receive traces and metrics from Datadog-instrumented applications

You can configure Alloy to collect Datadog traces and metrics and forward them to any OpenTelemetry-compatible database.

This topic describes how to:

• Configure Alloy to send traces and metrics.
• Configure the Alloy Datadog Receiver.
• Configure the Datadog Agent to forward traces and metrics to the Alloy Datadog Receiver.

Before you begin

• Ensure that at least one instance of the Datadog Agent is collecting metrics and/or traces.
• Identify where you will write the collected telemetry. Metrics can be written to Prometheus or any other OpenTelemetry-compatible database such as Grafana Mimir, Grafana Cloud, or Grafana Enterprise Metrics. Traces can be written to Grafana Tempo, Grafana Cloud, or Grafana Enterprise Traces.
• Be familiar with the concept of Components in Alloy.

Configure Alloy to send traces and metrics

Before components can collect Datadog telemetry signals, you must have a component responsible for writing this telemetry somewhere.

The otelcol.exporter.otlp component is responsible for delivering OTLP data to OpenTelemetry-compatible endpoints.

1. Add the following otelcol.exporter.otlp component to your configuration file.

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   otelcol.exporter.otlp "default" {
     client {
       endpoint = "<OTLP_ENDPOINT_URL>"
       auth     = otelcol.auth.basic.auth.handler
     }
   }

   Replace the following:

   • <OTLP_ENDPOINT_URL>: The full URL of the OpenTelemetry-compatible endpoint where metrics and traces will be sent, such as https://otlp-gateway-prod-eu-west-2.grafana.net/otlp.

2. If your endpoint requires basic authentication, paste the following inside the endpoint block.

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   basic_auth {
     username = "<USERNAME>"
     password = "<PASSWORD>"
   }

   Replace the following:

   • <USERNAME>: The basic authentication username.
   • <PASSWORD>: The basic authentication password or API key.

Configure the Alloy Datadog Receiver

1. Add the following otelcol.processor.batch component to your configuration file.

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   otelcol.processor.batch "default" {
     output {
       metrics = [otelcol.exporter.otlp.default.input]
       traces  = [otelcol.exporter.otlp.default.input]
     }
   }

2. Add the following otelcol.processor.deltatocumulative component to your configuration file.

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   otelcol.processor.deltatocumulative "default" {
     max_stale = “<MAX_STALE>”
     max_streams = <MAX_STREAMS>
     output {
       metrics = [otelcol.processor.batch.default.input]
     }
   }

   Replace the following:

   • <MAX_STALE>: How long until a series not receiving new samples is removed, such as “5m”.
   • <MAX_STREAMS>: The upper limit of streams to track. New streams exceeding this limit are dropped.

3. Add the following otelcol.receiver.datadog component to your configuration file.

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   otelcol.receiver.datadog "default" {
     endpoint = “<HOST>:<PORT>”
     output {
       metrics = [otelcol.processor.deltatocumulative.default.input]
       traces  = [otelcol.processor.batch.default.input]
     }
   }

   Replace the following:

   • <HOST>: The host address where the receiver will listen.
   • <PORT>: The port where the receiver will listen.

4. If your endpoint requires basic authentication, paste the following inside the endpoint block.

   alloy Copy

   basic_auth {
     username = "<USERNAME>"
     password = "<PASSWORD>"
   }

   Replace the following:

   • <USERNAME>: The basic authentication username.
   • <PASSWORD>: The basic authentication password or API key.

Configure Datadog Agent to forward telemetry to the Alloy Datadog Receiver

You can set up your Datadog Agent to forward Datadog metrics and traces simultaneously to Alloy and Datadog.

We recommend this approach for current Datadog users who want to try using Alloy.

1. Add the following environment variables to your Datadog-agent installation.

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   DD_ADDITIONAL_ENDPOINTS='{"http://<DATADOG_RECEIVER_HOST>:<DATADOG_RECEIVER_PORT>": ["datadog-receiver"]}'
   DD_APM_ADDITIONAL_ENDPOINTS='{"http://<DATADOG_RECEIVER_HOST>:<DATADOG_RECEIVER_PORT>": ["datadog-receiver"]}'

   DD_ADDITIONAL_ENDPOINTS is used for forwarding metrics, whereas DD_APM_ADDITIONAL_ENDPOINTS is for traces.

   Replace the following:

   • <DATADOG_RECEIVER_HOST>: The hostname where the Alloy receiver is found.
   • <DATADOG_RECEIVER_PORT>: The port where the Alloy receiver is exposed.

Alternatively, you might want your Datadog Agent to send metrics only to Alloy. You can do this by setting up your Datadog Agent in the following way:

1. Replace the DD_URL in the configuration YAML:

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    dd_url: http://<DATADOG_RECEIVER_HOST>:<DATADOG_RECEIVER_PORT>

Or by setting an environment variable:

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DD_DD_URL='{"http://<DATADOG_RECEIVER_HOST>:<DATADOG_RECEIVER_PORT>": ["datadog-receiver"]}'

Run Alloy

The otelcol.receiver.datadog component is experimental. To use this component, you need to start Alloy with additional command line flags:

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alloy run config.alloy --stability.level=experimental