> ## 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.

# Ingest metrics and traces using the OpenTelemetry Collector

The [OpenTelemetry Collector](https://opentelemetry.io/docs/collector/) is
vendor agnostic, open source, and supports popular backends and the OpenTelemetry
Protocol. You can use the OpenTelemetry Collector to ingest metric data, and configure
dynamic, remotely configurable
[head sampling](/control/shaping/sample-traces/head-sampling#configure-the-opentelemetry-collector)
for your trace data.

## Get started

To get started with the OpenTelemetry Collector:

1. [Instrument your app](https://opentelemetry.io/docs/instrumentation/) with an
   [OpenTelemetry SDK](https://opentelemetry.io/docs/instrumentation/).

2. Create an API token to authenticate with Chronosphere Observability Platform. You must
   [create a service account](/administer/accounts-teams/service-accounts#create-a-restricted-service-account).
   Chronosphere recommends creating a restricted service account with a write-only
   scope. Use the generated API token in the OpenTelemetry Collector file
   `config.yml` to authenticate with Observability Platform.

   <Warning>
     Store your API token in a secure location. If you lose your token, you must create
     a new service account.
   </Warning>

3. Configure your OpenTelemetry Collector to
   [ingest metrics or traces](/ingest/metrics-traces/otel/otel-ingest).

## Conversion from OpenTelemetry to Prometheus-compatible metrics

Observability Platform follows the
[OpenTelemetry to Prometheus Specification](https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#otlp-metric-points-to-prometheus)
to convert OpenTelemetry metrics to Prometheus-compatible metrics and adds delta
temporality aggregation support to provide a more seamless experience for delta
metrics.

Observability Platform implements the following data conversions as defined in the
[OpenTelemetry to Prometheus Specification](https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#otlp-metric-points-to-prometheus):

* Sanitize metric and label names to conform to
  [Prometheus naming conventions](/ingest/metrics-traces/collector/mappings/prometheus/prometheus-recommendations).
  For example, an OpenTelemetry metric named `http.duration` becomes `http_duration`.
* Collapse multiple consecutive underscore (`_`) characters to a single underscore
  character.
* Metric names for OpenTelemetry explicit bucket boundary histograms follow the
  OpenMetrics specification to correctly name the time series for each histogram
  bucket. For example, a histogram has one `_bucket` series for each bucket, and
  a series for the `_sum` and `_count`.
* Observability Platform supports staleness markers and writes them whenever any OpenTelemetry
  data point presents a `NoRecordedValue` flag for the associated scope.
* Observability Platform **requires** `service.instance.id` for all metric time series to
  ensure
  [metric writer uniqueness](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#single-writer),
  and **rejects** metrics without a `service.instance.id` resource attribute. To
  configure a value for `service.instance.id`, follow the recommendations in
  [Map resource attributes to Prometheus job and instance](/ingest/metrics-traces/otel/otel-ingest#map-resource-attributes-to-prometheus-job-and-instance).

  Observability Platform deviates from the
  [OpenTelemetry to Prometheus Specification](https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#otlp-metric-points-to-prometheus)
  to reduce operational chores and improve metric usability.
* Observability Platform preserves metric names and doesn't apply metric type or unit suffixes
  to metrics as defined in the OpenMetrics specification, with the exception of
  explicit bucket boundary histograms.
* Observability Platform drops OpenTelemetry resource and data point attributes
  that have empty values from the time series. Observability Platform then accepts
  the resulting time series for processing.
* Observability Platform merges both OpenTelemetry Protocol resource attributes
  and individual data point attributes into a single set of Prometheus labels for
  each time series. Merging resource attributes after ingestion removes the need to
  [manually configure resource attribute copying](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/exporter/prometheusexporter/README.md#setting-resource-attributes-as-metric-labels)
  in your OpenTelemetry Collector configuration. To configure resource attribute
  exclusions or turn off resource attribute merging, see
  [Configure OpenTelemetry ingestion](/ingest/metrics-traces/otel/otel-config).
* Observability Platform doesn't create a
  [`target_info`](https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#resource-attributes-1)
  metric by default. The `target_info` metric is equivalent to the `up` metric,
  the presence of which indicates that a resource is available. You can
  [change your configuration](/ingest/metrics-traces/otel/otel-config) to
  enable `target_info` metric creation.