> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chronosphere.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Configure your OpenTelemetry Collector

export const ApiTokenList = () => <>
    <em><code>API_TOKEN</code></em>: The API token generated from your <a href="/administer/accounts-teams/service-accounts">service account</a>. Chronosphere recommends storing your API token in a separate file or Kubernetes Secret and calling it using an environment variable, such as <code>$API_TOKEN</code>.
  </>;

export const MyTenant = () => <>
    Replace <em><code>TENANT</code></em> with the name of your Observability Platform tenant.
  </>;

You can configure the [OpenTelemetry Collector](https://opentelemetry.io/docs/collector/)
to send metric and tracing data to Chronosphere Observability Platform. You must send
all traffic over HTTPS.

<Tip>
  To learn more about OpenTelemetry, see
  [What is OpenTelementry?](https://chronosphere.io/learn/what-is-opentelemetry/)
  on the Chronosphere Blog.
</Tip>

Observability Platform accepts OpenTelemetry Protocol (OTLP) metrics from
OpenTelemetry Collectors by using the gRPC OTLP Exporter.

<Note>
  Chronosphere recommends not sending OTLP metrics directly from the OpenTelemetry
  Client SDK.
</Note>

This procedure adds each configuration section separately. For a complete file,
which you can modify as needed, see the
[OpenTelemetry configuration example](#opentelemetry-configuration-example).

## Prerequisites

To use the OpenTelemetry Collector, you need to
[create a restricted service account](/administer/accounts-teams/service-accounts#create-a-restricted-service-account),
which generates an API token you use to authenticate with Observability Platform. The
access you provide for the service account depends on how you use the OpenTelemetry
Collector.

| Use case                                                                  |                 Read access                |                Write access                |
| ------------------------------------------------------------------------- | :----------------------------------------: | :----------------------------------------: |
| Collect metrics                                                           |       <Icon icon="ban" color="red" />      | <Icon icon="circle-check" color="green" /> |
| Remote [head sampling](/control/shaping/sample-traces/head-sampling) only | <Icon icon="circle-check" color="green" /> |       <Icon icon="ban" color="red" />      |
| Collect traces plus remote head sampling                                  | <Icon icon="circle-check" color="green" /> | <Icon icon="circle-check" color="green" /> |

Chronosphere recommends storing the API token generated from your service account
in a separate file, or securely as a
[Kubernetes Secret](https://kubernetes.io/docs/concepts/configuration/secret/), and
reference it using an environment variable, such as `$API_TOKEN`. Binding a Secret to
an environment variable on the Pod is a well-supported, secure pattern in Kubernetes.

## Configure the OpenTelemetry Collector

To configure the OpenTelemetry Collector to ingest metric and trace data:

1. Pull the [OpenTelemetry Docker image](https://opentelemetry.io/docs/collector/getting-started/#docker)
   to run the OpenTelemetry Collector in a Docker container:

   ```shell theme={null}
   docker pull otel/opentelemetry-collector-contrib:VERSION
   docker run otel/opentelemetry-collector-contrib:VERSION
   ```

   Replace *`VERSION`* with the version of the OpenTelemetry Collector you want to
   run, which must be version 0.83 or later.

2. In the OpenTelemetry Collector
   [`config.yaml` file](https://opentelemetry.io/docs/collector/configuration/), apply
   the following settings to modify the `exporter` YAML collection. Specify an
   `endpoint` that points to your Observability Platform tenant, and include the
   Chronosphere API key you created as an HTTP header.

   You can modify the OpenTelemetry Collector
   [configuration](https://opentelemetry.io/docs/collector/configuration/) if you
   want to change the defaults. For example, you can reference a `config.yaml` in a
   different location, such as a Kubernetes ConfigMap.

   ```yaml theme={null}
   exporters:
     otlp/chronosphere:
       endpoint: TENANT:443
       timeout: 30s
       retry_on_failure:
         enabled: true
       sending_queue:
         num_consumers: 50
       # Valid values are snappy, gzip, zstd and none.
       compression: zstd
       headers:
         API-Token: ${env:API_TOKEN}
         Chronosphere-Metrics-Validation-Response: SHORT
   ```

   * `endpoint`: <MyTenant />
   * `timeout`: Set to `30s` to prevent larger requests from timing out, because
     the upstream system might require more time for internal batching.
   * `retry_on_failure`: Set `enabled` to `true` to enable retries for all retryable
     errors.
   * `sending_queue`: Set `num_consumers` to the number of consumers that dequeue
     batches from the sending queue. Increase the value of `num_consumers` if the
     exporter queue size demonstrates variability over time. A healthy sending queue
     metric depicts a small number of batches that shouldn't experience spikes over
     time. Chronosphere recommends setting this to 50 for
     [gateway deployments](https://opentelemetry.io/docs/collector/deployment/gateway/)
     of OTel Collectors.
   * `compression`: The compression method to apply. The Chronosphere OpenTelemetry endpoint
     supports `snappy`, `gzip`, and `zstd` compression, or `none`.
   * <ApiTokenList />
   * *`Chronosphere-Metrics-Validation-Response`*: The `ErrorMessage` verbosity for
     rejected metrics. Default: `SHORT`.

     Valid values are:

     * `SHORT`, which reports the number of rejected metrics.
     * `SUMMARY`, which also includes counts of rejection reasons.
     * `DETAILED`, which also includes a sample of rejected metrics.

3. Configure
   [batch processing](https://github.com/open-telemetry/opentelemetry-collector/blob/main/processor/batchprocessor/README.md).
   Sending telemetry in batches improves data compression and reduces the number of
   outgoing connections required to transmit the data.

   For example, the following configuration enforces a maximum batch size limit of
   `2000` spans without introducing any artificial delays:

   ```yaml theme={null}
   processors:
     batch:
       timeout: 1s
       send_batch_size: 1000
       send_batch_max_size: 2000
   ```

   The `timeout`, `batch size`, and `batch max size` are default recommendations.
   Monitor the exporter send and enqueueing failure metrics to tune these parameters
   based on your workload.

4. Add the OTLP exporter and the batch processor to the metrics and traces exporters
   definition.

   ```yaml theme={null}
    service:
      pipelines:
        metrics:
          receivers: [otlp]
          processors: [batch]
          exporters: [otlp/chronosphere]
        traces:
          receivers: [otlp]
          processors: [batch]
          exporters: [otlp/chronosphere]
   ```

5. Instruct the OpenTelemetry Collector to load the API token from an environment
   variable.

   <Warning>
     Never share or store your API token in plain text. Chronosphere recommends using
     tools like SOPs to securely store this information.
   </Warning>

   ```yaml theme={null}
      # In the OpenTelemetry Collector Deployment:
        - name: ${env:API_TOKEN}
          valueFrom:
            secretKeyRef:
              name: chronosphere-api-token
              key: apiToken

      # The accompanying Secret:
        apiVersion: v1
        kind: Secret
        metadata:
          name: chronosphere-api-token
          namespace: YOUR_NAMESPACE
        type: Opaque
        data:
          apiToken: ${env:API_TOKEN}
   ```

6. Save your OpenTelemetry Collector `config.yaml` file.

## Map resource attributes to Prometheus job and instance

Observability Platform uses the OpenTelemetry `service.namespace`, `service.name`
and `service.instance.id` resource attributes as the values for the Prometheus
[job and instance source labels](https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#resource-attributes-1).

* `service.namespace/service.name -> job`: Recommended. Observability Platform sets
  the job label value as a concatenation of `service.namespace` and `service.name`
  attribute values. If only `service.name` is set, then `job = "service.name"`.
  If neither `service.namespace` or `service.name` are present as resource attributes,
  then Observability Platform doesn't create a job label as part of the conversion.
* `service.instance.id -> instance`: Required. Observability Platform sets
  the instance label value to the `service.instance.id` attribute value.
  Observability Platform rejects the metric if the `service.instance.id` resource
  attribute is missing.

To ensure all metrics have a valid `service.instance.id` attribute, copy an existing,
unique resource attribute, such as `host.name` or `pod.id`, as the unique instance
identifier value for `service.instance.id`.

To define a default `service.instance.id` resource attribute:

1. Add a resource detection processor. Use the resource detection processor can to
   detect resource information from the environment. Append or override the resource
   value in telemetry data with this information. Configure the resource detection
   processor based on the environment where you've deployed the Collector. Review the
   [resource detection processor documentation](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/processor/resourcedetectionprocessor)
   to select the processor for your environment. For example, if the Collector is
   deployed on a host, the system processor is the best option to gather information
   about the host.

   ```yaml theme={null}
      processors:
        resourcedetection:
          detectors: [env, system]
          timeout: 2s
          override: true
   ```

2. Define a resource attribute processor.
   In the processors ConfigMap, define a rule to add the `service.instance.id`.
   The following example maps the `host.name` resource attribute to a new
   `service.instance.id` resource attribute. Depending on how resource detection is
   configured, your environment might have other resource attributes available, such
   as `k8s.node.uid`, which can serve as the instance identifier.

   ```yaml theme={null}
      resource/service-instance:
        attributes:
          - key: service.instance.id
            from_attribute: host.name
            action: insert
   ```

3. Add the resource detection and resource attribute processors to your metrics
   processors pipeline. In the `service.pipelines.metrics.processors` ConfigMap, add
   the resource attribute processor defined in the previous step:

   ```yaml theme={null}
   processors: [transform, batch, resourcedetection, resource/service-instance]
   ```

## Send operational metrics about the OpenTelemetry Collector

The OpenTelemetry Collector exposes metrics about its operations using a Prometheus
scrape endpoint. Observability Platform uses OpenTelemetry Collector metrics in the
OpenTelemetry Ingestion & Health dashboard to describe Collector health.

To send operational metrics about your OpenTelemetry Collectors to Observability
Platform:

1. Define a Prometheus receiver to scrape the endpoint receiver:

   ```yaml theme={null}
      prometheus/otel-collector-self-scrape:
      config:
        scrape_configs:
          - job_name: 'otel-collector-self-scrape'
            scrape_interval: 30s
            static_configs:
              - targets: ['0.0.0.0:8888']
   ```

2. Add the Prometheus receiver to the metrics pipeline:

   ```yaml theme={null}
     metrics:
       receivers: [prometheus/otel-collector-self-scrape, otlp/chronosphere]
   ```

3. Add the metrics service to the Service ConfigMap:

   ```yaml theme={null}
      service:
        telemetry:
          metrics:
            address: "0.0.0.0:8888"
   ```

## Next steps

Observability Platform should begin ingesting data. Verify the Collector is receiving
[metrics](/ingest/metrics-traces/collector/monitor/verify-metrics) and
[traces](/ingest/metrics-traces/collector/monitor/verify-traces). You can also configure
[head sampling](/control/shaping/sample-traces/head-sampling) to determine whether to drop a span or
trace as early as possible.

If you encounter issues, see the [troubleshooting](/ingest/metrics-traces/troubleshooting) page.

## OpenTelemetry configuration example

The following example is the entire configuration file, containing all of the
previously provided required sections:

```yaml filename="config.yaml" copy theme={null}
receivers:
  # OTLP receiver
  otlp:
    protocols:
      grpc:
      http:

  # Prometheus receiver configured to scrape the Collector's own metrics
  prometheus/otel-collector-self-scrape:
    config:
      scrape_configs:
        - job_name: 'otel-collector-self-scrape'
          scrape_interval: 30s
          static_configs:
            - targets: ['0.0.0.0:8888']

exporters:
  # OTLP exporter configured to send telemetry to your Observability Platform tenant
  # Replace the endpoint's `MY_COMPANY` and `API_TOKEN` with your values
  otlp/chronosphere:
    endpoint: "TENANT:443"
    timeout: 30s
    retry_on_failure:
      enabled: true
    sending_queue:
      num_consumers: 50
    # Compression method. Valid values are snappy, gzip, zstd, and none.
    compression: zstd
    headers:
      API-Token: ${env:API_TOKEN}
      # Validation Response verbosity. Valid values are SHORT, SUMMARY, and DETAILED.
      Chronosphere-Metrics-Validation-Response: SHORT

processors:
  # Detect environment information to include as telemetry attributes
  # Configure the detector from the list of available detectors:
  # https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/processor/resourcedetectionprocessor
  resourcedetection:
    detectors: [env, system]
    timeout: 2s
    override: true
  # Use environment information to define the `service.instance.id` attribute
  # This example maps `host.name` detected by the `resourcedetection` processor
  # to a new `service.instance.id` resource attribute
  resource/service-instance:
    attributes:
      - key: service.instance.id
        from_attribute: host.name
        action: insert
  # Add the batch processor to efficiently send telemetry
  batch:
    timeout: 1s
    send_batch_size: 1000
    send_batch_max_size: 2000

service:
  pipelines:
    traces:
      receivers: [otlp]
      processors: [batch, resourcedetection, resource/service-instance]
      exporters: [otlp/chronosphere]
    metrics:
      receivers: [otlp]
      processors: [batch, resourcedetection, resource/service-instance]
      exporters: [otlp/chronosphere]
    # Define a separate metrics pipeline to send the Collector's metrics to
    # Observability Platform
    metrics/internal:
      receivers: [prometheus/otel-collector-self-scrape]
      processors: [batch, resourcedetection]
      exporters: [otlp/chronosphere]
```